Category Archives: Photography

Green Screening Stills

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Hey Everyone:

It’s been quite awhile since I posted to my blog. It was a great Summer and Fall, but Winter is dragging on. But that also means I now have time indoors to try some Green Screen techniques. My setup is actually optimized for video; my lights are all continuous fluorescent. This actually cases problems for portraits, as I will explain later.

Goal –

I’m a big fan of a certain television series filmed in my home city of Albuquerque , New Mexico, and I needed a new headshot for my Facebook page. So I decided to take a self portrait, and transform myself into “Hines”+”enberg” = “Hinesenberg!”

[The character in the show is Heisenberg; named after the famous physicist who was one of the leading developers of Quantum Mechanics.]

This gave me an excuse to learn about green screens…

Equipment –

The image below shows my setup for the shot. The main lighting and backdrop are from “video” kit from Linco lighting. The kit is inexpensive, but the quality is surprisingly good. The total wattage is only 1500, but provides enough light for most amateur video applications, and still photography (but, again, causes issues for portraits). The kit comes with three octagonal reflectors that can be covered with diffusing material to convert them into softboxes. The octagons also have tension cords around their perimeters that allow the exit aperture to be reduced, even enough to form a “snoot.”  This is great for concentrating light into a confined beam and directing light where you want it.

Green screen setup.

Green screen setup in my living room.

I used two of the softboxes to uniformly illuminate the green screen background. This is very important, since any lighting gradients make “knocking out” the background much more difficult. It’s also important to make the background cloth smooth and wrinkle-free; again, wrinkles will cast shadows that will be hard to knock out in post.

I have some cheap, clamp-reflector lamps from the hardware store mounted low on the stands that I use to illuminate the bottom of the green screen for standing shots; I didn’t use them for this session.

I wanted illumination all over, with some interesting shadows as well.  So, to illuminate my face, I used my cheap umbrella diffuser on one side and a 5-in-1 reflector (with its silver surface) on the other.  The 5-in-1 reflector was supported by a reflector boom connected to a mic stand.  I also mounted a speedlight on my camera with a soft box attachment to provide front fill lighting.  I had the flash on 1/8 power so that the key lighting was from the umbrella, and the flash just removed harsh shadows.

I used my 50 mm prime focus lens to get a sharp focus, but short Depth of Field/Focus (DoF); this was to make sure that any remaining wrinkles on the backdrop were out of focus.

Shots –

Because I wanted short DoF, I used f/4.5, but this also meant I needed to focus on a subject with the correct height and distance from the camera. I used a small tripod to hold my jacket, sunglasses and hat (see image above), then focused on these. I also took several test shots with aperture priority and different flash settings to get a good exposure. I had a remote control to trigger the camera from my seated position in front of the camera, and took about 20 shots. It turned out that light from the windows in my living room caused troublesome reflections on my sunglasses, so I reoriented my pose and shot twenty more.

This is where I learned an important lesson. I was using a wide aperture and ISO 200. This meant the shutter speeds were moderate, about 1/60 to 1/100 seconds. This was slow enough that the images were blurred a bit by my motions. No matter how hard I tried to stay still, all of the images were slightly blurred.

In the future, there are three modifications that can address this. Brighter continuous lights would enable shorter exposure, freezing the action better. I could have used a higher ISO setting, especially since I was making a Facebook portrait that would not be affected by some added noise.  However, the best solution would be to get a couple of strobes for the softboxes. The flash would freeze the image regardless of the shutter speed (within the sync range).  That is what the pros do, and is clearly the best solution… Fortunately, my birthday isn’t too far off!

I next loaded the RAW image into Photoshop using the Adobe Camera Raw plugin. From there, the rest is just standard post-processing manipulation using layers.  The RAW image as shot is shown below.  The colors are not correct, but that’s the great thing about RAW; there is much more information in the file that is easily displayed.  This enables lots of head-room to make color corrections.

Note that the background is uniform, with no shadows or wrinkles. The backlight over my should helps give definition against the green background. Also note that I avoided any color on my wardrobe that had any green or blue hues. This also helps in knock out later.

Background Knocked Out & Crop

The image above shows the results after color-correction, background knockout, and a tight crop. The crop was not planned, but I had to crop it that way to crop out the top of the chair. I’d also planned a more rectangular, “portrait” crop. But again, the square crop made a better composition. In hindsight, these crops make for a much better composition.

I also had to do a bit of refining on the right side of my face and hat, because there was a bit of green reflection from the green screen. I knew this would be a problem, since I was too close to the green screen; only about three feet. It would have been better to be about five feet from the screen.

Green BB Smoke

Next I found a free wallpaper image of green smoke made to look like the opening credits from the show, dropped it into a background layer. The image is very sharply focused, and makes the blurring of my portrait more noticeable. I tried to blur the background a bit, but that made it less obvious that the image was green smoke filaments… It just didn’t look right.

So in the end, I just used the smoke image with full detail. I did adjust the levels of the smoke image a bit before compositing the background with my portrait.

Final Potrait of Me As Hinesenberg!

The image above shows the final product. You can see that the softness on me is caused by motion blur, rather than focus, because the blurred regions are located at a range of distances from the camera.

Aside from my double-chin (and the slight motion blur), the final result turned out pretty well. I think this is an appropriate homage to my favorite show… And a proper celebration of being 51 years on planet Earth!

[I have a special shot planned for my 52nd birthday… heh!]

I hope you found this useful, or at least entertaining.

Sharp focus and happy shooting.

Cheers,
Dean

Lenses

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Hey Folks:

In today's post I will discuss lenses. This is probably one of the most complex subjects in photographic hardware. So I won't be comprehensive, but I will try to touch the basics and give you some ideas about what you need for good photography. Even so, this is going to be a pretty long post, so thanks in advance for reading it.

While a point-and-shoot camera can take good photographs, you are limited in the scope of possibilities by the lens that's built into the camera. That is where a Digital Single Lens Reflex (DLSR) camera becomes essential, as it enables a wide variety of lenses to be attached to the camera body. There are literally hundreds of types of lenses available, but today I'm only going to discuss a few basic types that I feel are important for maximizing your photographic potential. But first we need to define some terms.

Focal Length

This rather long section contains quite a bit of jargon. You might want to skip it if you just want to get to the main points of this blog.

The focal length for a single element lens is the distance from the collimated input beam (typically the midplane of the optical element) to the focused image. For a fixed entrance opening, the longer the focal length, the smaller the Field of View (FoV), and the larger the magnification. [See this very good wikipedia page as well.]. For multiple-element, photographic lenses, the listed focal length is the distance from the last nodal point (typically about at the mid plane of the last optical element at the back of the lens) to the focal plane where the film or sensor is located. Becasue interchangable photographic lenses were popularized with 35mm film cameras, most focal lengths are referred to a 35mm equivalent. In the film days, most 35mm cameras came with a 35mm, prime focus lens (see discussion of prime lenses below)! This is because a lens with focal length similar to the image size at the film or sensor is said to be a Normal Lens; it produces an image that most matches the FoV of a typical human visual FoV, and looks “natural” or “normal.”

But there's a catch… Most consumer grade DSLRs have sensors that are smaller than the format of a film-based 35mm camera, which means that the FoV for these cameras is smaller for a given focal length lens compared with the 35mm. Therefore, you have to adjust for the ratio of the size of the sensor versus a 35mm camera to figure out your actual FoV on the camera. Most consumer grade DLSRs use CMOS APS-C format sensors. For Canon cameras with an APS-C sensor, this translates to a “crop factor” of 1.6 smaller in format size versus 35mm. So a 50mm lens on a Canon would have an FoV of an 80mm lens on a 35mm film camera. The factor is ~1.5 for Nikon APS-C cameras. This is important to keep in mind, because lens manufacturers now build lenses specifically for APS-C format sensors, with the FoV tailored to match the size of the sensor even though the focal length is 35mm equivalent. Therefore a lens specifically made for a camera with an APS-C sensor will show strong vignetting around the image edges if mounted on a full-format (i.e., 35mm sensor) camera. Because lenses can be more expensive than camera bodies, you should consider buying full format lenses if you ever feel that you'll be upgrading to full format body anytime soon. Another advantage of full-format lenses used on a APS-C camera is that image quality is almost always best near the center of the FoV, so a cropped sensor will sample the best part of the image from such a lens.

Zoom vs. Prime Lenses

Now that you've waded through all that technical detail, let's move on to a discussion on the two main types of lenses, zoom and prime. A zoom lens enables you to select a range of focal lengths, while a prime lens has a single focal length.

Zoom Lenses

Most consumer grade DSLRs come bundled with an 18-55mm zoom lens. These lenses are typically lightweight and deliver decent images, but they won't produce uniform image quality over the entire FoV at all available focal lengths. They are, however, very handy especially if you are shooting in different situations that require different FoVs (I used the term FoV instead of distance deliberately). These kit lenses run a couple hundred bucks. You can upgrade to better quality optics and lens mechanisms for under $1000; a professional level zoom lens can run a couple thousand dollars.

– Some considerations for zoom lenses

The least expensive zoom lenses are typically fairly slow; their lowest f/stop is 4.5 or worse, which means they are limited in ability to photograph in low light and cannot produce shallow Depth of Field (DoF). [See my blog about Aperture, Shutter Speed and ISO Setting.] These lenses also have variable minimum f/stop; as the focal length increases, the f/stop increases (this is related to the entrance pupil). They also change their lengths dramatically as they zoom, and the front of the lens usually rotates as it is being focused. This last characteristic makes polarizing filters and “tulip lens hoods” difficult to use.

The image on the right shows two zoom lenses, the Canon 18-55mm kit lens that came with my Canon t2i (550D) and a Canon 55-200mm kit-grade ltele-zoom ens. At full telephoto with a lens hood, these lenses can be pretty unwieldy. Fortunately, their plastic construction makes them fairly light-weight. Many mid-range lenses also extend quite far, but the front doesn't rotate during focus.

The high-end lenses have a fixed size, can often have fixed f/stop over the full range of zoom, and are fast. However, they can be very expensive, and are usually much heavier than their lower priced cousins.

Prime Lenses

The alternative to a zoom lens is the prime focus lens. These lenses have a single focal length, and thus a single FoV. Because the optical train is simpler than a zoom lens, a prime lens is usually lighter weight, has better image quality, and is faster… all for lower price (usually). While the cheapest prime might have a rotating front end during focus, most do not, so polarizing filters and tulip lens hoods are unaffected by focus changes.

Prime lenses are manufactured with a huge range of focal lengths, from 6mm fish-eye to ~2000mm telephoto, and lots in between. [This is an interesting article about an extreme telephoto lens.] Most consumer and prosumer grade telephoto lenses have focal lengths below 500mm.

– Some considerations for prime lenses

The most obvious limitation of prime lenses is that they have a fixed FoV. This means that you, the photographer, must actually move to frame the shot! On the other hand, this really will help you to improve your photography, even when applied later to zoom lens shooting.

The biggest advantage of prime lenses, aside from image quality, is speed. A prime lens can have very low f/stops; down to f/1.2, for very reasonable prices. This enables shooting in very low light situations and gives very fine control over depth of field. This latter feature is crucial for many portrait applications.

Prime lenses also often have good manual focus rings and focus distance indicators. This can be very important to achieve perfect manual focus, especially for portrait situations.

Prime focus lenses are also the best for achieving high quality video. Again, because of image quality and fine control over DoF.

Other Lens Types

There are a slew of other lens types, from macro, to tilt-shift, to fish-eye, to pancake lenses. If you're really into the types of photography that require these specialty lenses, then knock yourself out. But most people will not need these. The one exception might be a good telephoto macro lens, because it can do double duty as a macro lens, and as a general purpose telephoto lens. I will discuss microphotography in a future blog…

Which Lens for Is for You?

This question is the subject of dozens of blogs and websites, and there is a range of answers. After spending literally weeks reading through these, it appears that there is some consensus on the basic lens toolkit.

For beginners and intermediate shooters, the standard 18-55mm zoom lens supplied with your DSLR is adequate for most situations, and will get you started. You can upgrade to a mid-level lens that covers the same focal length range, but will give you better aperture control, including lower f/stops, better autofocus mechanisms, and better image quality overall. [Image quality is a complicated term that encompasses many different things including the modulation transfer function (MTF) [see this article also], contrast, field distortion, and chromatic aberration.]

The consensus for a must have prime lens appears to be a 50mm, often referred to as a “nifty fifty” because it is so useful. It's preferable to get an f/1.4, but that can set you back a few hundred dollars. An f/1.8 can be had for as little as $100, and will still provide superior aperture control and image quality compared to the basic kit lens. I managed to find a used Canon 50mm f/1.8 Mark 1, shown in the image to the left, for about $150 on eBay. I mention this lens specifically because it is no longer made, but is a really great lens. Unlike the newer, and cheaper Mark II, the older lens has a metal (as opposed to plastic) mounting ring, and it has a wide manual focus collar with a distance gauge visible through a small window. These features make this lens extremely easy to focus, and is especially useful for racking focus in video. I use this lens quite a bit. It is perfect for shooting stills for stock photography and online sales. Attached to extension tubes, it also makes a very good, fast macro lens.

And finally, a telephoto zoom is also very handy to have in your camera bag, especially if you like to capture images of wildlife (including the human kind playing sports). These lenses typically range from 55-270mm, which complements well the standard 18-55mm kit lens. The entry level tele-zoom lenses are actually pretty good for most situations, but as before, upgrading to a mid-range tele-zoom will produce superior images and (usually) provide lower f/stops.

The biggest problems with these tele-zoom lenses (and all lenses to some extent) are field distortion and chromatic aberrations, which are usually worse near the edges of the FoV. This can be minimized by centering your subject and cropping the image in post. However, this violates one of the foundations of good image composition; namely the Rule of Thirds in which the subject is offset from the center of the image.

Some software can also use the lens prescription stored in the metadata for the image to correct field distorion and chromatic aberation (especially for images saved in RAW format), but software can only go so far… It's better to start with a quality image.

Having said this, I have an entry level 55-250mm tele-zoom lens from Canon, and… I love it! The image quality is more than adequate for online use, and Canon has done a very good job of controlling distortion and chromatic aberration. The only issue I've had is that the lens is rather slow, which makes low light shooting difficult, and shallow DoF impossible.

Even if you opt for an entry level tele-zoom, make sure it has image stabilization. At focal lengths greater than ~100mm, it's very difficult to minimize camera shake. And because these lenses are slow, you'll need to use a long exposure time to capture the scene without increasing the ISO setting to unacceptable levels. This is actually true even for mid-range lenses… The limiting factor in your telephoto images will likely be image shake, not the quality of the lens. Of course, using a tripod will reduce camera shake dramatically, so I highly recommend having a quality tripod if you plan to shoot telephoto. [See my blog about tripods.]

One final consideration for any lens is its imaging capabilities as a function of f/stop. There are two aspects here: a) the quality of the image as a function of f/stop; and b) the actual construction of the iris that controls the size of the aperture. Most lenses have a sweet spot in the f/stop range, which is typically around f/8. This should be kept in mind when shooting critical shots, such as portraits or scenes with fine detail over a wide FoV.

In addition, the number of blades in the diaphragm, and their shape, can affect the image quality. While usually not noticeable in the focused part of the image, the diaphragm structure will affect the quality of the out of focus areas. This may seem silly. After all, the out of focus parts are… well… out of focus! But this is actually very important, especially if the out of focus areas contain light sources. The out of focus areas of an image obtained with a lense of finite aperture are called bokeh. Note that this is not simply a blurred area, it has structure imprinted by the shape of the diaphragm; features closer to or beyond the Depth of Field (focus) will appear to have the shape of the diaphragm. So if the lens diaphragm has five straight-edged blades, the bokeh features will also be pentagonal. [For all you atronomers and optical geeks like me, this is formally an image of the exit pupil, which is is itself an image of the diaphragm.] Such bokeh features can be very distracting in images with background lights such as candles or city scenes at night. It can really trash an otherwise great wedding shot. Just be aware. Less expensive lenses usually have less elaborate diaphragms, but even some more expensive lenses can suffer from this problem. Just be aware of the issue, and select a lens that meets your needs.

[Note that you can use the fact that the bokeh contains images of the entrance pupil to do some rather creative effects.]

A Final Note About Vintage (Legacy) Lenses

Some of us old-timers have lenses lying around from our days with film cameras. In my case, I have a Vivitar 28mm wide angle and a Minolta/Celtic 200mm telephoto, both with manual focus only and made for Minolta bayonette mounts. These lenses aren't worth much (about $20-30 on eBay), but the Vivitar has very nice optics, and it's fast (f/2.5). Old lenses are cheap and pretty easy to acquire. It might be a good idea to grab one or two if you see them at a thrift store or pawn shop.

Given that I already had a couple of lenses, I decided to get an adapter to mount them on my Canon t2i. You can get simple adapters for about $15-20, but these act as extension tubes, increasing the magnification of the lens by at least 2x. So, instead I opted to pay an extra $15 for an adapter that also has a corrective optic that is suposed to preserves the magnification of the original lens. Note that because these vintage lenses were designed for 35mm film cameras, the APS-C sensor will crop the image. But keep in mind that the original lens was designed for 35mm film cameras, so there will be a crop (see below).

Not surprisingly, the adapted telephoto produce poorer quality images than the Canon. The Celtic lens has really cheap optics anyway, so I didn't expect much. There is strong distortion and chromatic aberration at the edges of the frame, and stopping down the aperture doesn't improve things. The images on the right show a comparison between my Canon 55-250mm lens set at 200 mm, my Canon set at 250mm, and the Celtic 200mm telephoto, both set at f/8, and shot with Shutter Speed 1/60 and ISO 400. Even though the optics in the adapter are supposed provide a 1:1 image, there is still some extra magnification as evidenced by these comparison images. The good news is that the adapter does manage to preserve much of the image throughput; it preserves the approximate f/stop capability of the lens when mounted on the Canon.

The situation is similar with the Vivitar lens. However, the superior quality of the Vivitar optics is readily apparent. The image to the right shows a comparison between the Vivitar and my 18-55mm kit lens set at 28mm. Both images were taken at f f/3.5, since that is the fastest my kit lens will achieve. Both used ISO 400 and 1/60 Shutter Speed.

After my first draft of this blog, I did some additional research on the Vivitar 28mm f/2.5. Apparently, it is becoming quite a coveted lens for indie film makers, which is driving up the resale value. So the budget-minded might consider the vintage lens route; you won't get autofocus and image stabilization, but you can get very high quality glass. And with steady-cam rigs and tripods, the lack of image stabilization may not be a big issue, especially for shorter focal length lenses.

The image left shows a comparison between my kit18-55mm lens set at 28mm, and my Vivitar 28mm. the images were taken with f/stop f/8, Shutter Speed 1/60 and ISO Setting 400. (a) and (b) show the full frame of the kit and Vivitar lenses, respectively. (c) and (d) show an enlargement of the upper right-hand corners of (a) and (b). The kit lens produces good images even in the corners, but the adapted Vivitar is pretty terrible. I'm pretty sure that the adaptor optics are to blame here. But as I stated earlier the Vivitar is much faster. So I plan to hang onto the lens, especially for video.

Well, that's it for today. Thanks for slogging through this long post. I hope it gave you some ideas and information. Buying a camera body is just the beginning… It's the lens that makes the image. But most important, it's the person using the camera that makes a photograph. No matter how good the equipment, bad technique will not make a good photograph (I know… I take tons of bad pictures). On the other hand, good technique can do wonders with limiting and limited equipment. With the three lens types suggested herein, you should be able to tackle most any situation, or learning experience. Then, when you find that you need to upgrade, you'll have developed the chops to make the most out of that new equipment!

Happy Shooting!

 

PS – There are many, many great websites for photography, and I encourage you to visit them. But there are two that I go to regularly for information on specific equipment. They are dpreview.com and steves-digicams.com.

PSS – Here are two additional links to articles about lens selection. Article one, and article two.

 

White Balance

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Hey Everyone:

In today's blog, I'll be briefly discussing the sometimes mysterious topic of White Balance, sometimes referred to as Color Balance. In short, White Balance is simply the adjustment of the color in a photograph to render neutral tones, such as white, grey and black, so that they appear… white, grey and black! Because photographs capture light reflected, scattered or transmitted from/through objects, the color of the illuminating light source can impart a color cast to the image, altering the appearance of the scene. An extreme example would be a red light shining on a white surface; the surface will attain a red hue in the image. An obvious fix would be to change the color of the illuminating source, but this isn't always possible.

Because most light sources in the past were generated by heated filaments, or from the Sun, color is often described by a Color Temperature, and is given in degrees Kelvin. Warm objects emit a “black body” spectrum that can be characterized by a single temperature. Sunlight has a color temperature of about 5800K, while a tungsten filament has T~3000K, and a fluorescent light has T~5000K. An overcast day will have a color temperature of T~6500K, which means it appears blue; the warmer Sunlight is suppressed and the bluer light (due to Rayleigh Scattering in the atmosphere and to some extent in clouds) is enhanced. Higher color temperatures translate into “bluer” light.

[Note that this is easy to see on a dark night. The stars will appear to be different colors, from red to blue-white, because they have different effective temperatures!]

In the good old days of film, there were only a couple of ways to handle color balance. One was to use a film with different emulsions (e.g., Kodachrome, Ektachrome and Fujichrome). You could also use colored filters on the lens to compensate. Finally, colors could be adjusted during printing. With digital technology, color balance can be easily controlled in the camera or in post processing. So let's look at a few details.

Nearly all digital cameras have an automatic white balance setting, which is usually fairly accurate. However, there are many situations where the auto setting will not set the correct white balance. This is especially problematic when the scene is lit by multiple sources that have different color temperatures. In these situations, the camera can be switched to a specific white balance setting. These are typically, tungsten, fluorescent, bright daylight, overcast sky. Higher end cameras also allow the settings to be fine tuned. This is particularly handy for mixed lighting situations, but can be tricky.

When should you worry about white Balance? The short answer is “always!” But a better answer really depends on the situation. I've gotten in the habit of shooting almost all images in RAW. This mode provides the most flexibility for most photographic situations, even if I'm just trying get some snapshots for Facebook. This is because RAW format stores the native intensity information from the sensor with minimal processing, and with 14 to 16 bit precision as opposed to the 8-bit (256 individual brightness levels) typical of JPEG images (see this discussion about Color Depth). This added dynamic range enables very precise control over the final image in post-processing. And for this particular application, it means that you can control the final white balance in detail. This also makes it easy to apply different color corrections to different parts of an image.

However, there is a price to be paid in the form of much larger files, more computing power for post-processing, and additional steps in your workflow (images must be converted to TIFF or JPEG to be usable in image editing programs. So in some situations, like large panoramas, snapshots or some timelapse situations, using a standard white balance setting and JPEG compression will be fine. My Canon t2i has a cool mode that will store both RAW and JPEG versions of an image. This makes it easy to figure out when you can and cannot get away with using JPEG. As I alluded to, I like to use RAW, and especially in situations with high dynamic range with lots of bright areas and shadows, and when there are many different light sources.

Most descent photography applications like Lightroom, Aperture and Photoshop (with the RAW plugin) have handy white balance tools. You simply find a location in the image that should be white, click on it, and the software adjusts the white balance. I use this quite a bit, and have found that it works pretty well. But sometimes, there isn't anything white in the scene. So, I recently picked up a set of Digital Grey Kards. This is a set of black, white and grey plastic cards that you use to help either set a Custom White Balance setting for JPEG shots, or for adjusting white balance in RAW images during post-production. My set of cards from DGK was fairly inexpensive, and they are small making them easy to carry and use. I don't use them often, but for JPEG timelapse, they have helped in a few cases.

Finally, even though white balance is usually used to correct images for color cast to make them look more “natural”, white balance settings can also be used creatively to add a color cast to an image. Let's say you want to warm up an image to make it look a bit more like it was taken in the “Golden Hour”, you can change the white balance to enhance the warmer tones.

Well, that's it for today.

Happy Shooting,

Dean

 

Tripods

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Hey Everyone:

In today’s post, I will discuss tripods with an eye towards helping you find the one that best suits your needs. But first, why do you need a tripod?

If you want to move beyond simple snapshots, you’re starting to explore the various modes of your camera (see my post on Aperture, Shutter Speed and ISO Setting). In that case, there will be many occasions where handheld shots will not produce crisp images. Any time the shutter speed is slow, say below 1/60 second, even in a wide angle shot, the camera will shake enough to cause some noticeable blur. The blurring will get worse for longer focal lengths. In addition, there are many situations and photographic techniques that require the camera to remain in exactly the same position for a series of exposures. Finally, when shooting with a wide open aperture to provide a shallow Depth of Field (DoF), archieving focus on the primary subject can be very difficult without a tripod. So, aside from the camera and lens, a tripod is probably the most important accessory to add to your equipment.

Although not as stable as a tripod, a monopod is also very useful. Because I carry a walking stick almost everywhere for balance, I often substitute a monopod to have my camera with me. This is especially useful if you have a GoPro, because you can take that just about anywhere.

I will attempt to be fairly general in this discussion, bud I’ll be using specific examples from my (growing) collection of tripods and monopods: Manfroto 679 monopod; Vanguard Alta Pro 263AT; AmazonBasics 60 inch; Dolica GX600B200 Proline; Joby GP3 GorillaPod SLR-Zoom.

Considerations –

It’s useful to consider the types of photography that you’ll be attempting when choosing a tripod. No tripod will fill every need, but if you concentrate on a specific category, such as landscapes, portraits, sports, or macro photography, your ideal tripod might be different for each. Having said this, I will recommend my choice for the best all-around tripod at the end of this post.

Weight

A solid tripod is usually fairly heavy, which adds stability. Newer materials such as carbon fiber are becoming more popular and therefore less expensive, but lighter means it’s easier to tip over. Most lighter tripods, regardless of construction, will have a hook attached to enable a weight to be hung under the tripod to add stability.

Wooden tripods are great, because they are stable and the wood dampens vibrations, but they are heavy! They might be a good choice for a dedicated portrait studio, or static video shooting, but most of us will not want a wooden tripod.

As I mentioned above, carbon fiber tripods are becoming popular for their strength and light weight, but they are still pretty expensive. Aluminum/magnesium tripods are the most common, and there is a large selection at various price points. They are sturdy, and are robust against adverse weather conditions.

Legs

Aside from the obvious fact that a tripod has three of them, the configuration of the legs is an important consideration. Traditionally, the three legs are connected to a spreader that limits the angle to which the legs can expand. This provides added stability, but also limits the versatility of the tripod. Many of the newer designs forego the spreader, allowing each leg to be adjusted independently, and at a variety of angles. This really helps, especially in situations where the ground is uneven. This also enables the tripods to support the camera very low to the ground.

The number of segments for each leg and the mechanism for securing them is also a consideration. Tripods typically have two, three or four leg segments. This provides the ability to position the camera at a range of heights, and also makes it compact enough for easy transport. The trade offs are compactness, stability and weight. More segments usually provide a smaller collapsed unit for transport, but the extra hardware adds weight. In addition, each segment slides inside the one above it, so the last segment must be quite small, which compromises stability.

The image at left shows my tripods at their fullest extent. Except for the Joby GorillaPod, they all reach to about 60 inches without the head, and the Vanguard provides the heighest perch at 63 inches. In each case, I have extended the central tower as well as extended all of the leg segments. The ball heads add a couple of inches.

The Amazon and Vanguard tripods have three leg segments, while the Dolica has four (the monopod has three). At full extension, only the Vangaurd still feels sturdy. The Dolica, with four leg segments and rather light build, is the least steady. I would hesitate to have my DSLR at this height on the Dolica unless I was very careful. Also, wind shake would be noticeable as would vibrations, such as someone walking by on anything but a very solid surface. Hanging a sandbag or other weight might help, but that could also compromise the very thin fourth segments.

Adjustments to the leg segments are made with either a twist-tensioner, or with handled clasps. This is really a matter of preference, but I personally like the clasps. They are easily adjusted, at least on the better models, and they are easier for me to handle in general.

Feet

The feet at the end of the tripod legs are important. Inexpensive tripods typically just have a “rubber” or plastic tip, although my Manfroto monopod has a fairly “cheap feeling” tip… My Amazon tripod has flat-bottomed, gimbaled tips, which allows then to adjust to uneven surfaces. The Dolica and Vanguard tripods both have rounded, grooved rubber tips that are on spiked screws. This enables the rubber tips to be retracted, exposing the spiked tips, which can dig into the ground, carpet or icy surface. This last feature is very handy.

Heads and Head Mounts

There are four basic types of tripod heads: fixed, pan-tilt, ball and gimbal. Fixed heads are almost never used, because there is no easy way to adjust the camera other than the tripod legs. Pan-tilt heads are very common on inexpensive tripods, such as my Amazon tripod. They allow panning left and right, and tilt forward and backwards. Most also allow flip from vertical to horizontal. These heads can be very useful for video, and in fact I have a high end pan-tilt fluid head for just that purpose. However, they aren’t as versatile for still photography.

Ball heads are probably the most popular for photography. These have a panning base, usually marked with angle tick marks to enable easy stitching for panorama shots. There is also a ball release knob that loosens the ball clutch to enable the camera to achieve angles over at least 90 degrees of the viewing hemisphere. They also have a cut-out on one side that enables the camera to be oriented at 90 degrees for vertical (portrait), and thus 180 degrees of the viewing hemisphere.

The image to the above shows my tripod ball heads. From left to right are: (a) small head I use for my GoPro, usually mounted to my monopod; (b) the Vanguard SBH 100 head that came with my Vanguard; (c) the Optica head; (d) and the Joby head. While tripods usually come with a head, you can get just the legs and use the appropriate head for your application. The Vanguard head is by far my favorite, because it has a damped ball joint. The keeps the camera from just flopping over when the ball tension knob is released. This head also has big knobs, which makes them much easier to adjust. Unfortunately, it’s pretty heavy, and overpowers my Dolica.

These heads are all 3/8 mounted (see images on right). This is a bigger thread than the 1/4 20 that screws into your camera. However, there are adapters if needed. The thicker thread is important for heavier heads such as fluid head or a gimbal head. I won’t discuss gimbal heads here, because: I don’t have one; and they are typically used for very longline, and heavy, telephoto lens uses. Here’s a brief introduction to gimbal heads in photography.

Another aspect of the heads and mounts is the presence (or absence) of locking screws. A careful look at the mounts will reveal that only the Vanguard mount (see panel b) has locking screws. These are hex head screws that are tightened after the head is attached. They wedge into the grooves on the bottom of the head (see the image of the Vanguard head). While it’s not a big deal for ball heads, I have found it crucial for my fluid video head and would also be important for heavier cameras on any head. Because the fluid head has significant resistance for smooth panning, the screws are crucial to keep the head from unscrewing from the tripod mount. Keep this in mind if you ever plan to use a fluid head.

Center Tower

The center tower provides additional height to the tripod. it can also provide an additional degree of freedom in some models.

The Amazon tripod has a tower that is adjusted vertically by a crank mechanism. This is pretty handy, and helps ensure that there are no sharp drops when the securing knob is released. However, it also means that the tower cannot be removed, inverted or placed at a non-vertical angle. Both the Dolica and Vanguard tripods allow you to remove the tower to enable the tripod to be lower to the ground, and to invert the tower. This is very useful for getting low shots and for many macro applications.

I also find that the heft of the tower is important. In addition to the locking screws on the Vanguard, it also has a very sturdy tower. It’s the only tripod in my collection that can handle my fluid head without feeling like it will break.

In my post about photography of small objects for documenting collections or for online sales, I mentioned that my current tripod had a limitation that made it difficult to get the shot I wanted. To solve this, I purchased the Vangapuard, which has a tower that not only inverts, like the Optica, but also allows other angles. This turns out to be very important for shooting table work, where you want to place the camera high above the objects, but the tripod needs to be positioned offset from the camera. This is also important for many macro applications.

The image at right shows the Dolica and Vanguard tripods in t heir lowest configuration. The tower has been removed from the Dolica and the Vanguard tower is pulled out and angled. Both tripods. Enable the camera to be held level at about 4-5 inches above the ground. Again, the Vanguard is more versatile, and would allow a wide angle shot the avoids the legs being in the image.

Which Tripod Is For You?

That’s a tough question to answer. As you see, I have four, plus a monopod. As I said earlier, it depends on what you do most in photography. While a cheap tripod, like the Amazon, will work, you’ll likely find too many situations where it will get in the way. I actually bought the Amazon for mounting my Digital Audio redcorder and shotgun mics. it’s perfect for that. it’s also very handy for holding off-camera strobes and LED cinima lights. it’s so handy and so inexpensive, that I’m considering another one eventually. But it’s not ideal for mounting a camera for photography.

A tripod like the Vanguard will cover almost all msituations, but it’s fairly expensive (~$200, including the ball head), it’s pretty heavy (~6lbs), and it’s pretty big even when fully collapsed. The Joby Gorilla is really cool, and enables you to secure your camera to objects. But it’s not big enough for many uses.

A tripod like the Dolica is probably the perfect solution for most situations. It’s light (~4lbs), has a good range of adjustments, and comes with a good ball head. It collapses to a small enought package that it will fit in a carrying bag. It’s fairly inexpensive (~$55), and it comes with a very well made case.

A Mystery… Can you help?

Finally, I’d like to show you a handy little tripod that I’ve had for over 35 years! I don’t remember where I got it, but probably it’s was Kurt’s Camera Corral in Albuquerque, New Mexico. As shown right, this little gadget is about 6 inches, but extends to about 10 inches. It has a 1/4 20 thread in the base, so it can act as a ball head. Best of all, it has tripod legs that fold up inside for transport. I love this thing, but have never seen another one like it. If any of you can identify it, I would love to hear from you!

Well, that’s it for today. I hope this helps in your quest for a tripod. Let me know about your experiences.

Happy shooting!

Photographing Small Products for Fun and Profit

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Hey Everyone:

Spring cleaning has revealed a slew of small items lying around my home that either need documentation, or that need to be sold online. So, today I'll be sharing some experiences photographing small objects with the intent of documenting a collection, or selling things online. Well-photographed items not only look good, but the images can be sold to stock photography houses, and they definitely improve your sales success online.

Snapshot vs Photograph

I make this distinction often. A snapshot captures photons, but a photograph captures emotion and tells a story. This is especially important for sales, where you only get a few seconds to make that all-important first impression.

The vast majority of online images promoting an item for sale look like this image on the left. While this snapshot, taken with my trusty point-and-shoot camera, shows the product, it's flat and the background is somewhat distracting (I've seen worse, though). I deliberately used the in-camera flash, since this will be the natural tendency of folks when shooting in lower light situations. The image of each radio is very small, with too much space around the objects. The radios get “lost” in the scene. I could crop this tighter, which would improve the image dramatically, but the flatness and harsh lighting would still remain.

The image on the right completely changes the scene. There is no mistaking the subject, your eye is drawn immediately to the radios. The image is crisp and clean. The radios are well lit, and they are clearly three dimensional. There is no distracting background; the background is pure white, matching perfectly the standard white background on websites.

In addition, I have added some subtle shadows that enhance the three dimensional “feel” of the radios. The shadows are applied to give the illusion that the radios are floating just above the table. This adds to the three dimensional effect, letting the viewer get a better feel for the “depth” or “thickness” of the objects. This is especially important for the radio on the left, which is more face-on and lacks interesting extra structure (like a strap or antenna).

Making a Photograph Instead of a Snaphot

The key to producing a photograph of an object is lighting. While this is always the case for any photograph, it's critical for small objects. It's also important to have a very sharp picture. How many blurry pictures have you seen on eBay?

Large Depth of Field (DoF) is important to make sure that all parts of the object are in focus. But this typically means a large f/stop (small aperture), so you will need plenty of light to avoid high ISO Settings and the resultant high noise. (see my post on Aperture, Shutter Speed and ISO Settings).

It is also crucial to shoot your subject against a clean background. While many people like colored or patterned backgrounds, it's always better to shoot against a “green screen” or better yet, a backlit white background. Green screens are great for video, or when you have items with pure white colors. But a white background produces a very clean look, and makes it easy to “knock out” any non-white color. A translucent white background is even better, because you can add a backlight (see below).

Here's an inexpensive way to achieve a white background. I purchased a white poster board for about dollar at a local hobby store. I clipped it to a fiber board, and propped it in a chair. The smooth slope of the poster board ensures that there is no shadow at a seam in the background. I used my trusty umbrella diffuser to provide a soft general light. I used an off-camera flash, triggered wirelessly, with a diffuser to provide a key light. These sources didn't produce the proper lighting, so I used my old Vivitar flash, with Peanut optical trigger, to provide hard fill light form the right side. [Please read my post about vintage flashes BEFORE you use your vintage flash in any situation with modern DSLR cameras.]

The image to the right was the best I could obtain with this setup. I like it, and it shows off two prize possessions from my youth, but it's not great. The background just wasn't smooth and clean, and the whole scene is too flat. I could have spent hours trying to isolate the objects with the lasso tool in Photoshop and then redo the background, but I didn't want to spend the effort. The flatness is somewhat mitigated by converting the image to B&W. While the figurines are Pewter and appear B&W anyway, the B&W conversion gets rid of many distracting color artifacts. In addition, these images are still fairly noisy, even with the two flashes and umbrella light.

Shooting Tents and Tables

After trying my cheap setup, and producing only mediocre results, I decided to look into a more professional solution. There are many options, but two are most common: shooting tents and tables.

A shooting tent surrounds the subject in a translucent box, and external lights are used to illuminate the box. This provides a very soft and uniform illumination of the subject. While this is great for objects with non-specular (diffusing) surfaces, sometimes you actually want hard reflections for specular (shiny) objects, and this is not easily achieved with a shooting tent.

Instead, I settled on a shooting table. There are many varieties, and you can make one yourself, but I settled on this relatively inexpensive kit. It's fairly easy to assemble and disassemble, and it's very study. And best of all, it can be backlit!

This shooting table comes with a stand, and a translucent plastic sheet that has a diffusive surface on one side. The sheet is quite thick, which makes it a bit difficult to manipulate, but that also means it's sturdy and resilient to stains. The sheet is clipped to the stand with spring-loaded hand-clips; the clips also enable other backgrounds to be attached. I have a small CFL light under the table to provide illumination for focusing and framing (basically a “modeling light”). My main strobe flash is on the floor under the table; there's also a bracket on the table stand to attach the flash, but I wanted the flash to be further away. The flash is attached to a radio remote that is triggered by a twin attached to the hot shoe on my camera. My slaved Vivitar flash is sitting on the bench and pointed at a silver reflector. This extra light source provides additional top and side fill light.

I did discover that my tripod is not sufficient for this type of photography. I had to adjust the legs to lean the camera over the table, but that made it unstable, hence the red bag of junk hanging from the balance hook. I will discuss my ultimate solution to this tripod problem in a future blog.

Here is the final image. I've done some minor post-processing in Photoshop to ensure a pure white background, and then I added shadows using this awesomely simple technique. In a future post, I'll show the processing steps in detail, which includes nine layers for the shadows; but note that it only took me about ten minutes using the aforementioned technique!

Well, that's it for today. I hope this helps your online selling. At the very least, these techniques will continue to transform your snapshots into photographs, even for everyday images. And, best of all, it's a lot fun!

Until next time, happy shooting!

 

Apple Aperture and Adobe Lightroom

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Hey Everyone:

Today I'm going to very briefly discuss two software packages that enable you to maintain catalogs of your photographs, and that provide fairly sophisticated image editing capabilities. They are Apple Aperture (hereafter AA) or Adobe Lightroom (hereafter LR).

First and far most, AA and LR are cataloging packages for individual images. In this age of digital photography, libraries of photographs can accumulate into the thousands. Managing these can quickly become overwhelming.

Both packages offer powerful cataloging tools that enable you to classify, sort and maintain your image libraries. This is really key. Before I started using these, I would have to search through directory upon directory to find the image I wanted. I found myself wasting way too much time looking for a specific image. Now, once the libraries are built, it's much faster to find what I need.

While other software, such as Apple iPhoto (for Mac) and ACDSee (for Mac and Windows) provide basic cataloging, the features in AA and LR are much more powerful. In addition, while iPhoto and ACDSee offer basic image manipulation tools, AA and LR provide professional level tools. Both AA and LR provide tools for cropping, color correction, retouching, and support for RAW mode for most cameras. [I note that iPhoto and ACDSee continue to improve, so both are stil viable options to consider if they fit your needs.]

A full description of each is well beyond the scope of this blog, so I refer you to their respective websites: Apple Aperture – Adobe Lightroom

What's the difference between AA and LR?

The main difference between the two is really tied to workflow.

LR is compartmentalized, and follows the workflow that would be typical when using analog media (film, chemicals, enlarger, photo paper, etc). In LR you import, catalog, develop, edit, export/print, and make slide shows and picture books. Each of these is basically a module designed to be roughly linear in flow.

In contrast to LR, AA is very free form, and similar to iPhoto; the user does whatever they want, at any time in the workflow. AA offers basically the same capabilities as LR, so the main difference is simply this workflow philosophy.

I should mention that both have fairly broad user communities, so there are resources, including presets and tutorials, for both. LR does have a larger community, though, and so there are more resources in general.

What about Photoshop or GIMP?

Importantly, neither package is a replacement for pixel-based editors like Adobe Photoshop (hereafter Ps) or GIMP, which have many tools the you won't find in AA or LR. In fact, for individual image manipulation (and for certain video and animation needs), Ps and GIMP can do anything that can be done with AA or LR, but offer more pixel-based capabilities. Anytime you need multilayering or masking, Ps or GIMP is a must. Also, even though you can do everything on single images with Ps and GIMP that can be done with AA or LR, it's often much more cumbersome; AA and LR take the low level tools of Ps and GIMP, and make them more user friendly and intuitive.

Also, neither Ps nor GIMP offer any kind of cataloging. They also don't allow easy manipulation of metadata in the image headers. This last point has become more and more important, as information packed into the image headers becomes more extensive.

In my, and most other's experience, you will definitely want to have both types or software. GIMP is free, but Photoshop is quite expensive. Fortunately, Adobe offers a slightly less powerful version, Photoshop Elements.

Which program is for me?

That's a tough question. Unfortunately, Apple has decided to stop providing a free trial version of AA. The software is fairly inexpensive (but still not cheap), and the lack of a try-before-you-buy version seems like a ridiculous move by Apple. This might not bode well for the future of Aperture. In sharp contrast, there is a free trial version for LR. This is, in fact, what enabled me to evaluate LR against AA, and ultimately change to LR.

There are many discussions of which package to buy. Most eventually come to two main conclusions:

Go with Aperture if you already have and use iPhoto. It's trivial to transition to AA from iPhoto. Also, go with AA if you want to make photo books seamlessly.

Go with LR if you prefer the linear workflow model, and you'd like the advantage of a very large community of professional photographers.

In the end, even though I already owned AA, I have switched to LR. For this old-timer, who cut his photographic teeth in a real darkroom with enlarger, chemicals, and paper, the LR workflow is more intuitive. In a little less than a day, I was able to build a catalog of my 10,000 or so images, and learn most of the features. Of course, there's always more to learn… That's what makes it fun.

 

Until next time,

Happy Shooting

 

Aperture, Shutter Speed, ISO Setting: Part 2 – Some Illustrative Examples

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Hey Everyone:

In part one, I discussed the effects of Aperture (f/stop), Shutter Speed, and ISO Setting. I then presented you with some exercises to try that would illustrate the effects of these settings and how they are interconnected.

Today, I'm posting the results I got from doing these exercises myself. Even though I knew ahead of time what to expect in most cases, I ran into a few interesting surprises.

For all of the images shown, I shot in RAW mode. This produces larger files, but also maximizes dynamic range, reduces compression artifacts, and enables much better control and results in post-production. The RAW conversion was accomplished in Adobe Photoshop CS4, but no corrections were applied (just cropping, resizing and compositing). Click on the images for larger versions.

Exercises –

1) Shoot flowers in your yard. Set aperture priority and then photograph the same flower, but with different f/stop settings. What happens?

DoF

Since Spring is only now “springing,” I decided to photograph my favorite white, silk rosebuds instead of something outside.

For these photographs, I set my camera to Aperture Priority, Av on my Canon t2i (550D). As I increased the f/stop, the Depth of Field or Depth of Focus (DoF) increased – background objects became more and more in focus. This is great if you want to have objects at different distances stay in focus, but it's distracting when you want to highlight the main subject. A lower f/stop blurs the background, forcing your eye to look at the main subject, which is the flowers. This effect is very helpful for any scene with a crowded background (or foreground), and is essential for portraits.

2) Shoot running water, such as a stream, fountain or even a running faucet. Use shutter spread priority, and then take a series of shots at different speeds. What happens?

speed

I ran water in the kitchen sink, and photographed the scene with different shutter speeds. My camera was set to Shutter Priority, Tv on my Canon t2i.

The long, 5 sec exposure produced a very smooth stream of water; you can't see individual drops. As the shutter speed increased, individual water drops became resolved and finally “frozen” in time.

These effects can be used creatively. Very long exposures of rivers, water falls and moving clouds can really add drama and a feel of motion to your photographs. Of course, fast shutter speeds can be crucial for freezing action, especially in sports.

One important thing to keep in mind, however, is that the camera will have to adjust the aperture, and maybe the ISO setting, in order to achieve the correct exposure. In the running water images, you can see that the bottom right image is degraded by noise. This was caused by using a very short exposure in low light. The camera was wide open (so I had to carefully focus on a bottle at the same position as the water stream due to loss of DoF), and the ISO Setting was increased automatically by the camera to achieve correct exposure.

Note that slow shutter speeds can produce blurred images due to camera shake, so you'll need a tripod for some shots (I used a tripod for all of the shots in this blog post). Also, a Neutral Density (ND) filter is really important for situations where you want long exposures, but the scene is very bright, or you want a large aperture to control DoF. I'll discuss ND filters in a future blog.

3) Shoot a flat, well lit scene, such as a wall-hung picture. Set the camera to manual mode. Select a f/5.6 and shutter speed 1/125. Take a shot. Now change the f/stop to the next higher number (e.g., f/8) and shutter to the next longer speed (e.g., 1/100). Take a shot. Now try the opposite experiment. What happens? This should give you a feel for the interplay between f/stop and shutter speed.

Exposure

Here are two photographs of a reproduction Picasso painting that's been in my family since I was a kid. The two shots were taken in full Manual Mode with ISO 1600, and White Balance set manually to Fluorescent (this last bit isn't strictly necessary, but I didn't want anything to change in these photographs except Aperture and Shutter Speed).

The top image was taken with f/6.3 and Shutter Speed 1/60 sec. The bottom image was taken with f/8 and Shutter Speed 1/40 sec. Both images have the same Exposure Value (EV), meaning they both have the same range of brightness, even though they each have different f/stop and Shutter Speed settings.

Note that my Canon t2i has intermediate Shutter Speeds and Apertures, so simply changing the f/stop by “one click” does not mean a change in f/stop by “one stop.” [see part 1] The same is true of the shutter speeds. In these cases, the metered value measured by the camera will show you when the EV's are the same.

The point of this exercise was to illustrate the interplay between f/stop and Shutter Speed. Namely, that the same Exposure Value can be achieved using different combinations of f/stop and Shutter Speed, and that they are inversely related to each other. This is important to keep in mind when using either Aperture or Shutter Speed priority to get your shot.

4) Shoot a simple scene in low light. Set the camera to manual. Adjust the shutter speed and aperture to get a good exposure. Now take a series of shots with different ISO values, starting with ISO 100 and increasing by at least four or five settings. What happens?

ISO

For these images, I set the camera to Portrait Mode so that the camera would automatically adjust the Aperture (f/stop) and Shutter Speed, but let me manually adjust the ISO Setting. [Portrait Mode attempts to always use the widest aperture possible to decrease DoF, which is important for… well… portraits!]

You can see that as the ISO Setting increases, the images become noisier. In fact, this exercise revealed a surprise about my Canon t2i; the noise is not uniform in all three color channels. Even in shooting in RAW mode, the noise in the Green channel increases more rapidly than the Blue and Red channels. This causes a green color cast to the higher ISO images. Such a color cast can be adjusted in post, but it's annoying. I suggest testing you camera before you find yourself in a high-ISO situation; I had not know about this for my camera!

ISO_Zoom

These next two images show a zoomed region of the ISO 100 and ISO 12800 photographs. The increase in noise and annoying color cast are apparent. Such higher noise could really degrade an enlargement, even though there are plenty of pixels (and thus spatial resolution) in the image.

In general, you should use the lowest ISO Setting possible in any shooting situation. Again, this is especially true for portraits, and if you plan to enlarge the image for printing. If you use Av or Tv settings to achieve DoF or Shutter Speed effects, be careful if you have your camera set to AUTO ISO; you might get the shot, but it might be noisy. It's always better to set the ISO manually for important shots. If you can't get the correct exposure, then start adjusting the ISO Setting to larger values.

Having said all this, there are some situations where you just need to get the shot (like your kid sleeping in a darkened room with feet hanging off the bed). In those cases, turn on the camera's noise reduction (if not already engaged) or try to clean up the image in post. Note that cleaning noise in post-production inevitably leads to reduced spatial resolution, making the image blurrier. Again, this can be disastrous if you intend to make enlargements. Fortunately, Photoshop has a variety of noise reduction algorithms, some of which are not as aggressive and will cause less blur. Apple Aperture and Adobe Lightroom have noise reduction tools as well.

Well, that's it for today. I hope you learned something; I sure did. Give these exercises a try. If you do, let me know what happened.

Next time, I'll be posting a short discussion about Apple's Aperture and Adobe's Lightroom software packages, which enable you to handle RAW images, catalog your photographs and make corrections to them. I'll also explain why this die-hard Apple fan just switched from Aperture to Lightroom.

Until then, happy shooting!

 

Aperture, Shutter Speed and ISO Setting

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In today's installment, I'm going to review the three primary controls used to set proper exposure of your camera. When you use the camera's “automatic” mode, these settings will be set by your camera to provide the best overall exposure for the scene. While convenient, this is one of the main reasons that images look like snap-shots, rather than photographs! By understanding these controls, you will be able to obtain properly exposed images, but you now have much more creative control. So let's abandon the automatic controls and get one with producing photographs.

Aperture –

This is the size of the opening in the camera that allows light to enter; typically controlled by an adjustable diaphragm in the lens. Wide apertures let in more light than small apertures, providing the most rudimentary exposure controls. However, the aperture size has another effect; it changes the depth of field or focus (DoF) of the captured image. Any kid who's made a pinhole camera knows this, because a pin-hole camera only works when the entrance aperture is… well… A pinhole.

A wide aperture will have a shallow DoF, where the primary object will be in focus but the foreground and background will be blurred. A narrow aperture will provide a well focused image of the foreground, object, and background. Most tablet and smart phones, and miniature cameras such as the GoPro, have narrow apertures to enable them to shoot very crisp images without the need for a focus mechanism. Unfortunately, this can cause a picture to be very cluttered, because everything is in focus, not just the main subject. On the other hand, there are times when you want everything in focus, but an automatic camera setting might open the aperture to better exposes the scene, thus blurring out the fore and backgrounds.

The solution is to use the “aperture priority” setting on your camera. This allows you to set the aperture for the correct DoF, and then the camera will set the shutter speed and/or ISO to yield the proper exposure. I find myself using this setting at least 60% of the time for still photography.

The aperture setting is often referred to as the f/stop. Since the amount of light admitted through the aperture is proportional to the area of the opening, the f/stop is measure of the Apertue. Each f/stop represents an aperture that is the square-root of two larger or smaller in radius, and thus admits a fair of two in light. The actual f/stop number is the reciprocol of the aperture size, so changing the f/stop from f/5.6 to f/8 reduces the amount of light entering the entrance aperture by a factor of two. This last fact is really all you need to know, since it will relate directly to the settings for shutter speed discussed next.

Here are two Wikipedia reference pages for aperture and f/stop.

Shutter Speed –

The shutter speed determines how long the film or sensor are exposed to the incoming light; slow shutter speeds increase the time that the shutter is “open” thus increasing the amount of light accumulated, and vice versa. Typically, slow shutters are used in low light situations, while fast shutters are used in bright light.

But there's a catch: moving objects will tend to be “motion blurred” with slower shutter speeds. This might be undesirable if you're shooting fast moving subjects such as athletes, cars, planes, or a child at play. Or, you might want a slow speed to intentionally blur the scene to make a waterfall more dramatic, for example.

In these situations, you can use the shutter priority on your camera to set the desired speed, and the camera will set the aperture and/or ISO to achieve the correct exposure.

I noted above that a change in one f/stop changes the amount of light by a factor of two. Shutter speeds setting are designed to also change the amount of light by a factor of two. Thus changing the shutter speed from 1/60 to 1/125 will reduce the light by a factor of two. If you were to also change the f/stop from f/8 to f/5.6, that would increase the light entering by two, and the overall exposure of the image would remain unchanged. This interplay between f/stop and shutter speed is the primary key to creating photographs as opposed to snapshots!

Here are two Wikipedia reference pages for shutter speed.

ISO Setting –

Finally we need to discuss the ISO setting, as I used to know it in the US, ASA. The International Organization for Standardization (ISO), is an international organization that maintains standards for a variety of measurements and other specifications. In the current context, ISO refers to the sensitivity of the sensor to light. In the film days, this mean that the emulsion on the negative had larger crystals that absorbed light and changed their opacity to make the image. Higher ISO meant larger grains and more light sensitivity. Today, for digital imaging sustems, the ISO setting refers to the “signal gain” on the detector. Larger ISO numbers mean that the camera is more sensitive, and it will therefore make an image in lower light.

However, higher ISO settings also bring added noise. In film, the larger crystals make the image more grainy. In the digital age, the higher ISO, and thus gain, increases the random noise on the image. In addition, higher ISO will also make bad pixels and any structure in dark current be more promenant. Lower ISO will always provide a better quality photgraph, but some situations will require higher ISO settings. It's always best to start with the lowest setting and only increase the value if you are unable to achieve your desired explore by adjusting the aperture and the shutter speed.

Higher end cameras now have noise reduction that can significantly improve image quality even at higher ISO settings. And some cameras will actually take a “dark” image to remove bad pixels and dark current structure; this age-old standard for astronomy imaging has made its way into commercial photography!

Here is a rather dense technical description of ISO that includes a discussion of ISO as applied to digital cameras.

Experiment

Now that you have some understanding of the non-automatic controls on your camera, you should challenge yourself to not to use the automatic setting….ever! Ok, there is one time when the automatic setting is very useful, and that's when your kid is doing something impromptu, and you don't have time to mes with the controls…

Exercises –

1) Shoot flowers in your yard. Set aperture priority and then photgraph the same flower, but with different f/stop settings. What happens?

2) Shoot running water, such as a stream, fountain or even a running faucet. Use shutter spread priority, and then take a series of shots at different speeds. What happens?

3) Shoot a flat, well lit scene, such as a wall-hung picture. Set the camera to manual mode. Select a f/5.6 and shutter speed 1/125. Take a shot. Now change the f/stop to the next higher number (e.g., f/8) and shutter to the next longer speed (e.g., 1/100). Take a shot. Now try the opposite experiment. What happens? This should give you a feel for the interplay between f/stop and shutter speed.

4) Shoot a simple scene in low light. Set the camera to manual. Adjust the shutter speed and aperture to get a good exposure. Now take a series of shots with different ISO settings, starting with ISO 100 and increasing by at least four or five settings. What happens?

 

Next time, I'll post my results from these excercises.

Until then, happy shooting!

 

Very Important – Using Vintage Flashes with Modern Cameras

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Hey Folks:

Happy New Year!

Summary – don’t use an old flash unless you are 100% sure it won’t damage your digital camera. Read on to find out why!

For this blog post, I was originally planning to cover some basic camera functions that really improve your shots, but instead I’m going to review some informational about flashes that could potentially save you a pile of money, and keep you from “bricking” (frying) your digital camera.

Many of us old timers have some vintage equipment in the closet, garage or basement. When I was digging through my old Minolta equipment, I came across my trusty old Vivitar 235 flash.

It’s a dinosaur from the 1970’s, but in the days when cameras didn’t even have a built-in flash, it was all I could afford and it worked pretty well (especially held off-camera hooked to a PC sync cord).

Since I hadn’t gotten a new flash yet for my new Canon t2i (550D), I thought I’d just put the Vivitar on my new Canon. I don’t know why, but I decided to look up some info on using this old flash on my Canon, and discovered that using it would probably fry my new camera… Making it an expensive “brick” or doorstop! What?

It turns out that older flash gear typically used a higher voltage to trigger the flash than is used in modern systems… often 100-250 volts. This was before modern CMOS technology, when most electronics was still discrete transistors that handled high voltage and current. Modern camera equipment uses much lower voltages, typically 5 volts. So using an old flash has the potential to fry the new electronics.

Here’s some sites that list flash trigger voltages, here, here and here.

If you do want to use your old flash, I’d personally recommend only using it for off camera fills and special effects. In that case, I also recommend not triggering it with a PC cord connected to your camera… Just be safe. Instead, either rely on the flash’s slave features, or as I just did, buy a cheap optical slave adaptor. I found this helpful guide to optical triggers here. A brief overview of how to use that old flash for a range of applications can be found here.

Since my old Vivitar flash only has three power settings, I decided to get a Wein Peanut trigger bought from B&H, but is also available for Adorama. The system works great for my purposes; adding background bounce light, or special effects. The Peanut works great for my applications. If you need to trigger wirelessly, then you probably want to go with newer flashes anyway.

In closing, if you have an old flash, beware. You should definitely be very careful using it on your DSLR unless you are sure that it will not damage your gear. On the other hand, having some extra flashes around can be very useful.

Until next time.

Cheers,
Dean

Remember that the best camera is the one you have with you!

Basic Equipment & Software

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For my first post on photography, I thought it would be useful to present a list of gear that I have found to be essential, either through direct experience or through recommendation by other sources. In all cases, though, I have used the gear or software listed.

I claim no expertise, but I hope that I can save you some time and money when plowing ahead. I’ve definitely spent a lot of time, and unfortunately squandered a few dollars on the way, so maybe I can save you some of both.

This section is divided into two main parts that describe the “Absolutely Essential Gear” and the “Minimal Software” required to get you some great shots.

Absolutely Essential Gear

  • Camera (duh). But seriously, get a good DSLR. Canon and Nikon are great choices. Mine is a slightly outdated, but still incredibly capable, Canon t2i (550D). I got it used off eBay (one of my favorite ways to stock up on equipment).
  • Lens (duh again). But this one isn’t so obvious. Most DSLRs come with a kit zoom lens. That have good optics, and they deliver great results. If you can only afford one lens (for now), stick with a kit lens like a 18-55mm zoom. Note that the focal length of lenses are always given in 35mm “film” equivalent terms. Most lower cost DSLRs have a sensor that is smaller than the focal plane of standard 35mm film camera. In my case, the effective focal length is 1.6 x the listed focal length. So a 50mm film camera lens will behave like an 80mm on my Canon t2i. Here’s a convenient calculator for converting focal lengths for many popular cameras.
  • Camera Strap. Most cameras come with some type of strap. Be sure you have one that is wide and adjustable. It needs to be long enough that you can carry the camera across your body and easily pull your arm back through to carry only about the neck. A wrist strap can be added, but should not be the primary strap. Here is a nice summary of strap types and usage.
  • Case. You need a good case/bag to protect your investment! I have four cases, mostly because I have accumulated them over the years. So I now have several sizes; I can take a small one for light travel, or a big one to take lenses, extra filters, and extra batteries.
  • Tripod. I debated about where this item should be listed. But after thinking about my photography over the years, it’s clear that a ‘good’ tripod is essential. I’d advise against a cheap ‘travel’ tripod. I’ve had one for years, and it works. But my new (to me) DSLR is way too heavy to be stable for many situations. On the other hand, my old Davis & Sanford travel tripod only costs about $12 and now I use it for a flash stand. Instead, buy a good quality tripod. I just got a Dolica GX600B200 for about $55 on Amazon. It comes with a nice ball-head and a case. It’s a great tripod for the money. A better option is the Manfrotto 055XPROB., but it will set you back $150 and you’ll need to buy a separate ball-head $100 and even a case!

Minimal Software (so you can get good results)

You need a way to download and manipulate your images on the computer. I use Apple hardware exclusively, so I will only be discussion products that run on that platform. Fortunately, most of the software I mention will run on both Mac OS and Windows systems. Most of the products also have trial versions, so you can see how they behave before you shell out the cash.

  • Downloading Utility. Most cameras will come bundled with software for this. But third party software will work as well. For example, iPhoto for Mac works well.
  • Image Cataloging and Basic Manipulation. You will definitely need some software to edit, adjust and touch-up your photographs. iPhoto and ACDSee both work ‘ok’. These provide cataloging and basic manipulation. Apple’s Aperture and Adobe Lightroom also have cataloging and manipulation, but are also designed for more professional level phtographers. I’ve been using Aperture, and it beats the heck out of iPhoto.
  • Pixel-Based Editor. In addition to cataloging and basic touch-up, you’re going to want a pixel-based editor. This enables compositing, cloning, masking, and many features available in a traditional darkroom like dodging and burning. I’d actually say that this type of software is more important than a cataloging program. Ultimately, the best, most powerful option is Adobe Photoshop CS6, hands down. But it is expensive!!!!!! This is the industry standard, and I have used it for photography and astronomy for over 15 years. You can get slightly older versions, new or used, on eBay for less than CS6, and they will work well. Don’t go earlier than CS4, since many of the technologies you’ll need weren’t available in those very early versions. Another good option is Adobe Photoshop Elements, for about $70. It has many of the most common features, and is geared towards the hobbiest. If you’re on a tight budget, there’s the free GIMP. It’s very powerful and has much of the functionality of photoshop, but (and it’s a big but), it’s interface is tedious and often confusing. Try it.

If you get started with the equipment and software listed here, you’ll be prepared for most situations. With a few tips on how to use this equipment, your shots will go from “snap shots” to “photographs.” At least that’s what happened to me.

Next time I’ll discuss some camera basics that I’ve known for a while, but have relearned for DSLR, that will really improve your shots, whether artsy landscapes, or pictures of a child’s birthday party.

Cheers, Dean