One of the primary things that attract people to reefkeeping is the amazing diversity of organisms available to the average aquarist. The eye-popping colors, patterns and details found in some aquatic species appear so fantastic as to seem unreal. The first time I stepped into a saltwater fish store I was awestruck - who wouldn't be? But what's more amazing, and perhaps harder to appreciate, is the minute detail… so tiny and intricate, it's nearly impossible to fully comprehend the complexity with the naked eye. A good close-up photograph shows things that you might not be able to fully appreciate without the help of a camera. This article will provide some tips on how to improve your close-up photography skills so you'll be able to share your aquarium's infinitely detailed glory with others.

For those of you who have digital point-and-shoot cameras, some of the following techniques will be slightly different from shooting with digital single lens reflex (dslr) cameras, although many of the tips hold true for dslr cameras, too. Briefly, a point-and-shoot camera is one that comes with a lens (usually a zoom lens) that is permanently attached to the camera. A single lens reflex (slr) camera uses a variety of interchangeable lenses, allowing the user to choose the most effective lens for any photograph. Camera manufacturers make a wide variety of lenses, which ultimately give the photographer greater creative flexibility. Point-and-shoot cameras offer ease of use and the convenience of small size and portability. They're also much less expensive than dlsrs.

Terminology

First, let's discuss a bit of the terminology that is important for close-up photography. The photographic term "minimum focus distance" refers to the point that is the shortest distance from the camera that the lens is able to focus on. This is a key piece of information in determining how effective a camera/lens will be for shooting close-ups. It's also a critical piece of information to know in order to get the best close-ups the camera is capable of taking. Consult the camera's manual to find out exactly what its minimum focus distance is. This distance, and the lens' focal length, are the two most important factors to consider when calculating how the camera will perform for close-up photography. The focal length isn't as big a consideration with point-and-shoots, though, because nowadays most are designed so that the best close-ups are achieved at the widest part of the lens. If you're looking into buying a particular point-and-shoot camera for taking close-ups, the most important factor is the minimum focus distance. For more tips on buying a camera, please see my previous Reefkeeping Magazine article.

"Magnification" describes the subject's true size compared to its size on the sensor or film. Another term that's used a lot for this kind of photography is "macro." In the photographic world, this term has a specific definition, even though it's widely misused or, shall I say, used more widely. The true definition of macro is (at least) 1:1 magnification - that means when comparing the subject's size in real life to its size on film, it will be the same size (or larger) on the piece of film (or image sensor). Last of all, "depth of field" is a term that is particularly important. Depth of field is defined as the distance between the closest and furthest points in the photograph that appear to be in sharp focus. (For an overview of what an aperture is, and how it affects the depth of field and shutter speed, please see my previous Reefkeeping Magazine article.)

Most of today's point-and-shoot cameras have a "macro" mode; when the camera is put into macro mode, usually by pressing a button on the back of the camera, the lens can focus considerably closer than in its regular focus mode, thus allowing the best possible close-ups. When focusing on something far away, you merely need to take the camera back out of macro mode by pressing the macro button once more. A fairly new feature that camera manufacturers are designing into point-and-shoots is a "super macro" mode. In this mode the camera can focus on something extremely close to the lens - sometimes even objects touching the lens. This has the potential to make for some very interesting photographs. If you want to take a picture at the greatest magnification your camera is capable of, common sense would have you zoom all the way in (full telephoto) to get the most magnification right? Wrong! Most point-and-shoot cameras get the greatest magnification with their lens at its widest angle. Keep that in mind if you're having trouble getting your camera to focus properly. Another important fact to contend with is that as the camera is moved closer to the subject, the inherent depth of field decreases. So, to achieve good depth of field on extreme close-ups, we're forced to use very small apertures. Remember that bit of information when shooting at your camera's minimum focus distance. If you're new to photography, a picture with a very narrow depth of field can easily be misinterpreted as out of focus.

Focus

Focusing is problematic in all types of aquarium photography. Close-up shots present their own challenges to an autofocus system, but when a layer of glass or acrylic, some water and a few hundred tiny particles are added between the lens and the subject, it's a very difficult situation indeed! So don't be too hard on your camera - the odds are stacked against it! Luckily, a work-around is available that will help - even with the toughest subjects. In aquarium photography most focus problems arise from dealing with subjects that lack adequate contrast and texture, and from introducing the added confusion of layers of acrylic, water and floating particles. The work-around is to focus on something that has a lot of contrast (and texture) first. Find something that has good contrast and texture that's the same distance from the lens as your intended subject and press the shutter release button half way down to activate the autofocus. Once the camera has the focus locked, recompose the shot -- just make sure to keep the button pressed half way down so the lens retains that focus point. When the picture is framed back up on your intended subject, press the button the rest of the way down to take the picture. It takes a little practice, but the results are worth the extra effort. This works well for fast-moving kids, too. Another important tip is to always shoot into the tank perpendicular to the glass or acrylic, to minimize distortion from the tank's material. This distortion can usually be seen in the LCD viewer before the picture is taken, so watch closely for it and make small adjustments in the camera's position to get the shot just right.

Some point-and-shoot cameras can be focused manually, usually through some type of magnification feature on the LCD. My experience has been that this feature is usually less than ideal for close-ups, but still worth experimenting with if the camera has the capability.

Depth of Field

If you're a beginning photographer, one of your first questions will likely be, "What settings do I use to get the best close-ups?" Because so many variables are specific to each photograph and photographer, more information is required to make the best recommendation. In other words, there is no simple, one-size-fits-all group of settings. When determining what settings to use, the first thing to consider is depth of field. How much depth of field do you want? Try to train yourself to visualize the image after it's taken. If you can picture in your mind how you want the image to look, then you can choose the settings that will get what you're after… as long as the depth of field concept is understood. This photo shows a very narrow depth of field:

The goal of this shot was to make the single Clavularia polyp in the frame's bottom right stand out by blurring the Acanthastrea background. To achieve that effect I needed a very small depth of field. The aperture setting was approximately f4.

This is an example of an image for which I wanted a large depth of field:

On this shot I used a very small aperture (f8), because I wanted the entire Echinophylia and pipefish to be in focus.

Shutter Speeds

I like to use aperture priority exposure mode for close-up photography. The reason is that good depth of field is usually the most challenging thing to achieve in close-up photography. The aperture setting is the factor that determines how much depth of field you'll end up with. When the camera is set to aperture priority, the camera figures out what the correct shutter speed will be for the best shot. Even though the camera figures out the shutter speed, you still need to be aware of it because the shutter speed determines whether or not a tripod is needed or if moving subjects will appear blurry. If you've decided a lot of depth of field is not needed and the subject is stationary, you might be able to get a fast enough shutter speed to allow taking the picture by holding the camera in your hands, as opposed to using a tripod. Here's a general rule of thumb regarding shutter speeds and handholding the camera: sharp results are achieved if the shutter speed is at least 1/focal length. For example, if you have a 100mm lens (or a zoom lens zoomed to a 100mm focal length), a shutter speed of at least 1/100th of a second is needed. Familiarize yourself with your camera and where to find the shutter speed (and aperture) information when the picture is displayed in playback mode, and use this rule of thumb to determine if a tripod is needed. Remember, too, that as the camera zooms further in, camera shake becomes more pronounced. More than likely, a tripod will result in sharper pictures, even when using fast shutter speeds. With slow shutter speeds a tripod is a must. Another reason to use a tripod is that it gives you time to carefully inspect the composition so distracting elements can be removed from the frame, the horizon can be leveled (when applicable), and the subject can be placed in the best possible position. Most cameras come with a self-timer feature that provides a delay between the time the shutter release button is pressed and when the picture is actually taken. Using the self-timer is another way to get sharper pictures because we inevitably jiggle the camera slightly when pressing the button, and even the slightest jiggle is enough to affect sharpness at slower speeds.

Accessories

Some accessories are available that will improve your camera's close-up performance. The good news is that, for the most part, they won't break the bank, either. The most common and least expensive is a close-up filter set; they come with three filters in different magnifications (usually +1, +2 and +4). These filters increase magnification by shortening the minimum focus distance of the camera's lens. Simply put, the closer the camera is to the subject, the greater its magnification. These filters screw onto the threads on the front element of the lens and can be used individually or stacked together for maximum magnification. A small step up from the filter sets, in terms of optical quality and cost, are multi-element close-up filters. Many manufacturers make quality close-up filters (B+W, Canon, Nikon, Tiffen, etc.). You've probably seen super macro close-up filters in the 10x range. Yes, these will greatly increase the magnification. However, they shorten the minimum focus distance to such a great extent that depth of field is massively reduced. To get even a tiny amount of depth of field, the smallest aperture your camera is capable of will need to be used, which in turn means long shutter speeds will also need to be used. Additionally, a tripod will be necessary, and you'll be limited to subjects that are stationary or moving very slowly. Another commonly available accessory is the telephoto adaptor. These adaptors increase the lens' focal length and are good for bringing faraway subjects closer, but they have limited use in close-up photography because they also increase the minimum focus distance. Consult your camera's documentation to determine if your camera requires an adaptor to use filters, and be aware that certain low-end point-and-shoot cameras don't have filter threads, so they can't accommodate an adapter.

Flash Photography

Flash use in aquarium photography presents an opportunity, but it also has drawbacks. The opportunity arises from the introduction of a large amount of light. When a flash is used effectively, the results can be stunning. Photography is about compromise… the photographer always has to determine where the best compromise is between depth of field and a shutter speed that is fast enough to freeze movement. There is rarely enough light for our needs - even in the most brightly-lit tanks. We can increase the ISO to get a faster shutter speed, but the higher the ISO, the grainier the picture will be. I always try to use the lowest ISO setting possible to maximize the picture's quality. A more detailed explanation of ISO can be found in this article. Adding a burst of light from a flash allows the photographer to choose much smaller apertures for much greater depth of field, or to choose much faster shutter speeds - or both; that is the beauty of the flash! For this close-up of zoanthids (below) I wanted a lot of depth of field, but I also needed to use a fairly fast shutter speed because I was shooting handheld. In manual exposure mode an aperture of f8 and a shutter speed of 1/90 were used, and the flash was fired.

In manual exposure mode both the shutter speed and aperture are set by the user, and if a flash is used, it becomes the main light source. In most cases the foreground subject will be well-lit and the background will be darker when the subject is a significant distance away from the background. If the subject and the background are close to each other, the whole scene will be fairly evenly-lit. If aperture or shutter speed priority is used, the flash will act as a fill light, supplementing the light that's already present. This technique can result in a very natural appearance when done correctly; however, because the flash is only a fill light, the shutter speed will be the same as without the flash. This technique is good for subjects that aren't moving much and/or those that don't require a lot of depth of field. It's a particularly effective technique for filling-in shadowy areas and is well-suited to situations encountered outdoors. Generally speaking, though, manual exposure mode is more useful for aquarium close-ups because it gives you the opportunity to use fast shutter speeds and small apertures.

Exposure Compensation

You may find that your pictures are being over (or under) exposed when using a flash. Don't worry - that beast can be tamed! Consult the camera's manual on how to set flash exposure compensation - usually its icon is a lightning bolt with a tiny plus/minus symbol. If the picture is too bright, negative exposure compensation should be set. It's best to experiment to determine just the right amount of compensation, but don't worry if your first picture comes out too bright; setting negative compensation will reduce the flash output and get that picture looking good. The same goes for situations where the picture is too dark. Exposure compensation is something to familiarize yourself with even when not using a flash. Aquarium photography frequently requires compensation because of the strong light source coming from directly above the subject; this creates a scene that has a lot of contrast (very dark and very bright areas). A couple of warnings about using a flash for aquarium pictures: to avoid getting the flash's reflection in the picture, aim the camera slightly downward. Also, certain subjects look unnatural when they're lit with a flash. Most Acropora species and many zoanthids, for example, will turn dull colors, so it's usually best to avoid using a flash with them.

The arrival of digital cameras is the greatest thing to happen to photography in a long time. We can practice to our heart's content and not have to worry about film and developing costs, and we can see right away if the picture came out the way we wanted it to. So practice! Take some of the suggestions in this article and use them, and then study the results. And post your pictures in the Photography Forum to get help, or just to show off.