Wide-angle & Close-up Photography
As an underwater photographer, a limitless range of opportunities awaits you, from close-ups of tiny creatures to wide reef scenes or large animals. A wide selection of lenses is available for SLR cameras, ranging from 14 mm (or even less) to monster lenses in excess of 600mm (which have little use for the underwater photographer). Zoom lenses cover varying portions within this range. Lens focal length is a prime factor in determining the properties of a lens and the things it will do for you. Short focal length lenses cover wide angles and allow close focus, while longer lengths have decreasing angles of view and longer minimum focus distances. Lenses in the 200mm range and beyond are considered telephoto. Macro lenses are designed for close-up photography and usually are at or near 50mm and 100mm. Marine biological photography above and below water can make use of all these wide angle, telephoto and macro lenses. Underwater your choices are somewhat more limited, but nevertheless permit a wide range of possibilities.
Youre diving off the coast of California on a calm winter day with 80-foot visibility (it can happen!). A shadow looms overhead and you look up at the belly of a passing gray whale (not likely to happen!). Hopefully youre not equipped with an extension tube set-up. What you need is a lens with a wide angle of coverage, like the Nikonos 15 mm (about 94 degrees). Even when several feet away from something as large as a whale, you can include a large portion of the subject in the image. A key in successful underwater photography is to get as close as possible to the subject to minimize the degrading effects of the watery environment on light and the image. Closeness is even more critical in areas like California and New England due to the frequent blooms of phytoplankton and floating particles. Wide-angle lenses permit you to get close to large subjects yet still include them in the image frame.
Equipped with a wide-angle lens, you are capable of getting those images of invertebrate reefs, kelp forests and whales. Wide angle Nikonos lenses include the 15mm, 20mm and 28mm. The 15mm focuses the closest of the group and has the widest angle of coverage. Of course, you pay the price for this privilege. This fine piece of glass is often the first choice for photographing large swimming animals like whales and whale sharks. It also works well for close focus wide-angle photos in which you have a subject one to three feet away in the foreground and a background area in the distance. The incredible depth of field of this lens enables foreground and background to usually be in focus together. Since this lens has such a wide field of view, subjects that are relatively small can disappear in the image. Make sure your subject is sufficiently large or close so that it takes up the desired area in the image frame. If your wallet is not quite so deep, the 20mm Nikonos lens is a fine wide-angle tool. It doesn't focus quite as close as the 15mm, has a smaller field of view, and at a given distance and aperture, a reduced depth of field (this is a general property of all lenses shorter focal lengths have a greater depth of field at a given distance). The 28mm lens is a good starter lens when purchasing a Nikonos system if your budget is limited. It requires more care in estimating focus due its less generous depth of field. Sea & Sea also makes a variety of wide-angle lenses for use with the Nikonos. Since the Nikonos is a viewfinder camera (rather than SLR) an accessory viewfinder will be necessary. You will need to develop skills and techniques for composing your image properly, particularly when focusing on something within 1 or 2 feet.
Housed systems provide a near limitless number of choices for wide-angle photography. Only the number of lenses available for your particular SLR camera limits your selection. Zoom lenses, such as 20-35mm, are also possible. This enables you to change the size of the area covered in the image. Regardless of the lens you use with your camera, if it has a focal length of about 35mm or less, a dome port will be needed for the housing. This type of port has a curved surface that corrects the severe refractive distortion you would otherwise have. Dome ports create a virtual image about a foot in front of the port. The lens must be capable of focusing this close in order to form a sharp image. Short focal length lenses should have no problem with this. Lenses of 28 to 35mm may not be capable of focusing down to a foot and often require the use of a screw-on close-up diopter lens. Dome ports also must be positioned correctly for each lens to be capable of forming a sharp image. Adjustment shims are generally available on metal housings that enable the lens to be matched properly with the port. If the quality of your wide-angle images is not satisfactory then an adjustment may be necessary. Images that are fuzzy throughout even when the lens is focused all the way down indicate the need for a close-up diopter. Unsharp corners, on the other hand, may be a sign that the dome port is not positioned correctly for that lens (wide-open apertures can also do this). Extreme wide-angle lenses in the range from 14 to 18mm will require an extra-wide dome port.
With sufficient ambient light, a variety of underwater images can be made without a strobe. Silhouettes, kelp forest scenes, jellies, shallow coral reefs and sea lions are some of the suitable subjects. Clear sunny days work best for this type of photography. Overcast conditions result in dull, colorless images when a strobe is not being used to pump up the colors. A light meter is generally necessary to obtain the desired exposure for the background. With a Nikonos camera you can use the internal meter, while the meter in a housed camera usually works fine. An alternative for both systems is to use an external Sekonic Marine Meter, which has a nice easily viewed read-out of aperture settings.
Backlighting using the sun can make for stunning images. The idea is to position the sun directly behind the subject (such as a jelly or sea lion) such that only the rays of light are visible. A light meter reading can be made at a point of intermediate brightness away from direct sunlight. If you meter too close to bright sun, the indicated aperture will be too small and the photo will be underexposed. A meter reading from a shadow area, on the other hand, will result in overexposure of the bright sun area. Housed cameras have an advantage in that more precise positioning of the sun in relation to the subject is possible. In shallow water with bright sun, you can also photograph with the sun behind you, thus providing front lighting on the subject.
Using a combination of ambient and strobe lighting permits a wider variety of photographic possibilities. The idea is to combine background ambient light with strobe fill lighting of foreground subjects that would otherwise be left in the dark. The result should be a natural illumination that doesnt give away the fact that an artificial light source was used. The natural effect is enhanced by an exposure producing blue (or often green in California and New England!) background water. Most good wide-angle underwater photographs make effective use of this lighting combination.
Good visibility and sunny skies go a long way toward making a good wide-angle photo opportunity. If the water is excessively murky from plankton or particles, or overcast skies create dim conditions, it may be better to forgo your efforts in favor of close-up photography. Assuming you luck out and the water is clear and the sky sunny, you only need to find a suitable subject. In California waters that could be colorful invertebrates on a rocky reef or a group of rockfish beneath the kelp canopy. At this point position yourself with the subject in the foreground from 1 to 4 feet away and the desired background behind. Including the ball of the sun in the image frame generally makes for a more dynamic photo. To do this youll actually need to point the camera in an upward direction. Although it may not appear to be the case, most wide-angle photos that include a blue background with sun are made with the camera pointing upwards rather than horizontal. This also has the effect of isolating the subject to make it stand out from the background. Once you have an idea of how to compose the image, you can make a light meter reading from an area of intermediate background brightness. If the sun is in the photo area, meter a bit to the side in order to obtain an exposure for a natural appearing background. This meter reading will be what determines the aperture setting on the camera. To obtain a dark or black background, close the aperture at least 2 to 3 stops from the light meter reading that would produce normal brightness.
Only after determining the appropriate aperture for the background should you think about the appropriate strobe exposure. You should have a clear understanding of the distance / aperture relationship for your particular strobe. A wide-angle strobe will also be necessary. Its beam should be wide enough to cover the area of your lens. Using a small strobe with a wide-angle lens will probably result in dark, underexposed edges in your image frame. The following are for manual exposure settings for both camera and strobe. If, for example, the ambient background is about f/8 and your strobe requires an f/8 aperture at 3 feet subject to strobe distance, then you will need to be about 3 feet away from the foreground for an accurate exposure. With this strobe, a background aperture of f/11 would mean a foreground subject to camera distance of about 2 feet. If you remained at 3 feet, the foreground would likely be underexposed. What happens if the ambient light reading is f/5.6 and you still want to be 2 feet from the foreground subject? At full strobe power you would overexpose the foreground by about 2 stops (the difference between f/11 and f/5.6), creating an unnatural appearance to the photo. In this case you can switch the strobe to ¼ power to balance the exposure. You can also vary the amount of strobe light on the foreground by increasing (reduced exposure) or decreasing (increased exposure) the strobe to subject distance by moving it back and forth. Reducing the shutter speed (from 1/60 to 1/30 second for example) is also a way to increase ambient exposure without affecting the strobe exposure. Bracketing aperture and strobe position is recommended to increase the chances of getting that winning exposure combination.
How about if you like using automatic exposure and TTL (through-the-lens exposure automation)? If the foreground subject area covers less than somewhere between ¾ to ½ of the image area, its probably best to forgo TTL exposure in favor of manual settings. Remember that there are actually two exposures to consider: the ambient light exposure, which is measured by the light meter, and the strobe exposure measured by the TTL sensor. This sensor is most sensitive to a relatively small area in the center of the image. A small off-center foreground area may confuse the TTL sensor into thinking that more light is needed, resulting in overexposure. The ambient light has no effect on the exposure determination by the TTL sensor. In this case its better to control the lighting and use manual strobe exposure settings, or at the very least trying it both ways. The ambient light exposure determines what aperture setting you should use. If, for example, you set the aperture at f/8 for a TTL strobe exposure with a subject distance of 3 feet, the foreground will be exposed properly, but the background will be overexposed if it required f/11. You can control the strobe output more easily than the ambient background light.
Housed cameras and the Nikonos are both suitable for doing ambient light / strobe combination exposures. With the Nikonos you can set the shutter to A (automatic ambient exposure) or to a manual shutter speed of 1/60 or slower. At a setting of "A" the shutter speed automatically is set at 1/90 second when the strobe is turned on. When determining the background exposure, turn the lens aperture control until both 1/125 and 1/60 are illuminated in the viewfinder. This indicates a proper aperture for a shutter speed of 1/90. Once the aperture is known you can then determine the appropriate strobe setting and distance. With a housed system and automatic camera, youll have a choice of several exposure modes: manual, aperture priority, shutter priority or program. Aperture priority should be avoided since a slow shutter speed may be the result. Program exposure leaves too much to be decided by the camera, so manual or shutter priority for the ambient light exposure may be your best bet. With either mode you can use manual or TTL strobe exposure control.
Wide-angle lenses can also be used to photograph relatively large subjects without any background area contributing to the exposure. In this situation, TTL generally works fine, or you can use the standard strobe / subject distance relationships. Large fish, groups of anemones, and sea stars are some of the subjects appropriate for close focus wide-angle photography. The closer your lens can focus the better since you can reduce the amount of water between camera and subject. Since the strobe is contributing all the light to make the exposure, you dont need to worry about light meter readings.
Use of a single strobe can result in undesirable shadows on the foreground subject area. A second strobe can fill in the shadow areas and produce more pleasing, uniform foreground lighting. If the second strobe is at least 1 stop less powerful than the main strobe, then a camera exposure adjustment may be unnecessary. With two equal power manual strobes, youll need to adjust the exposure by closing the aperture by 1 stop since twice as much light is illuminating the subject area. Ideally the second strobe will be 1 to 2 stops less powerful in order to produce some shadow area that adds depth to the image. Equal strobe lighting produces an unnatural-appearing flat lighting. The second strobe can either be adjusted to ½ or ¼ power, held at a greater distance, or diffused by a piece of white translucent plastic. Once again, you can use manual or TTL strobe exposures.
Dont neglect wide-angle marine biological photography above water. Places like northern California, Maine, Oregon and Washington have an incredible variety of stunning shoreline areas. Tidepools exposed at low tide, sea lions hauled out on shore and waves crashing along rocky coastlines are a few of the limitless possibilities. Ambient light will play the dominant role in wide-angle photography. Unless its your intention, high noontime sunlight or thick foggy, overcast days present a less desirable type of lighting. Early morning or late afternoon light, which casts a more pleasing golden glow, is generally going to provide the best opportunity. Stormy winter days can also produce dramatic lighting and stunning sky backgrounds. Generally you will want to have the sun at your back or somewhat to the side so that the subject area is immersed in a uniform light that minimizes harsh shadows. Along the coastline, if the angle of light from sunset comes from the wrong direction for your desires, then you can always try the same spot at dawn, when the sunlight will come from the other side of the horizon. You can also try backlighting, where the sunlight illuminates the subject from behind and can create a luminous halo around it.
Ultra-wide lenses are nice when you can get close to the subject and still have a pleasing area farther off in the background. With a lens in the focal range from 12 to 18mm, you can get very close to photo subjects in a tidepool, allowing the viewer to feel as if they could step into the image. These lenses should be used with care since a small subject will be lost in the frame if not sufficiently close. Lenses in the range from 20 to 35mm are less prone to this problem, but cover less area and have reduced depth of field at a given distance. When using a wide-angle lens, you should meter more in the area of the subject rather than the sky, which tends to be much brighter. Including too much sky in the meter area will usually result in underexposure of the lower part of the image. Polarizing filters can help to reduce sky brightness and aid in balancing the exposure. Another possibility is the use of a graduated neutral density filter. This filter reduces exposure in the upper part of the image by 1 or 2 stops, thus making the exposure of the bright sky more in line with the darker foreground. With careful positioning of the filter, you should not notice the reduced exposure in the upper half.
When possible, you should use a tripod for wide-angle photography. In addition to precise compositional control, this allows you to use faster shutter speeds with smaller apertures, and thus greater depth of field. This way you can have foreground and background subjects in focus. With a steady hand you certainly can hold the camera if a tripod is not available or possible. Generally as shutter speed is reduced, camera movement becomes more of a possibility. Even though a shutter speed of 1/8 or ¼ second sounds pretty fast, its not fast enough to eliminate the effects of even small amounts of hand shaking. The general rule is that you should not use shutter speeds any slower than the reciprocal of the lens focal length. For example, with a 20mm lens, shutter speeds less than 1/20 second may suffer from camera movement. With practice and development of technique, though, you may be able to successfully use slower speeds.
Most decent diving locations offer a wealth of close-up subjects you can spend an entire dive on a rock wall in search of small photo subjects. Exposure control is generally a bit more straight forward than for wide-angle since the exposure usually is based entirely on the strobe lighting. There are situations where you may want to balance ambient background light and strobe light, even with close-up photography, but most of the time the strobe will be the dominant source of light. Close-up (also known as macro) photography requires that you get the lens very close to the subject in order to form a large image on the film. There are several ways to accomplish this.
With a Nikonos camera, extension tube sets are available that extend the lens from the film plane, hence magnifying the image. The greater the extension, the greater the magnification. A typical extension tube set has three tubes for 1:3 (1/3 life-size on film), 1:2 (half life-size) and 1:1 (life-size). Each tube has its associated framer for determining image size and focus distance. The framer is positioned with the intended subject within the area of the framer bars. Care must be taken to make sure the desired area of focus is within the plane of the framer. You will only have a fraction of an inch depth of field on either side, which declines as you increase magnification. In many instances the shape or position of the subject area makes it difficult to position the framer as desired. You should try various framer positions and avoid the standard top-down view that is typical of many beginner efforts with framers. Close-up lens attachments that fit over the main lens and allow it to focus closer are also available. Either way, youre not really seeing the image while composing it, so you will need to develop a skill for anticipating what the final result will look like.
Housed systems permit the use of macro lenses and through-the-lens viewing and focus control. This allows close approach to the subject without having framers get in the way. Macro lenses in the 50 to 60mm and 90 to 105mm ranges are generally used underwater. Some will focus down to 1:1 magnification, while others can only go down to 1:2. Macro lenses are designed to permit the lens to be extended farther from the film plane, thus increasing image magnification. Extension tubes accomplish the same thing. With a macro lens you can photograph at image sizes from 1:2 (or 1:1) to 1:10 or more, all on the same dive. Unlike framers with a Nikonos camera, you are not limited to one setting. Generally for lens magnifications of less than 1:10, macro lenses are not very useful since you will be several feet away from the subject. In this case a wide-angle lens would be more appropriate. The 100mm macro lens doubles the working distance between lens and subject when compared to the 50mm. This can be useful when photographing hard to approach subjects like many fish. Its also easier to position the strobes when working at higher magnifications. The downside is that you are increasing the amount of water between the lens and subject. With murky, particle laden water, you may produce a better quality image with the shorter focal length macro lens.
Since macro lenses can extend up to several inches, a long port is required to accommodate the extra length. Macro lenses typically use flat rather than dome ports. Refraction thus magnifies the image a bit and reduces the lens angle of coverage, but this is not usually a problem. With manual macro lenses a ring attaches to the lens barrel, which then mates with the housing or port to permit focusing. Autofocus lenses are focused electronically and thus do not require an attachment. You may, however, desire to retain the ability to focus manually if the housing permits. With manual focus its generally best to set the focus point (such as 1:3) and move the housing back and forth until the desired point of focus is reached. Autofocus lenses are rapid enough to allow you to select the subject area and then let the camera do the focusing electronically. With dim conditions you may need to bring an accessory light to aid focus otherwise the lens may shift back and forth without being able to focus properly. Your strobe may have a built-in modeling light; otherwise youll need to bring a dive light and attach it to the strobe or housing. Housings often block the infrared autofocus aid that many cameras possess. If you have the technology, by all means try autofocus but be aware that it may not always work as desired.
Close-up photography requires precise control of composition for best results. Most housed cameras have relatively small viewfinders that can make it difficult to see all the subject area. The Canon F-1, an older manual camera, has the ability to attach a special large viewfinder that allows easy viewing of the entire subject area. Unfortunately newer cameras in the Canon line lack this feature. Nikon F-series cameras (F3, F4 and F5) also have the potential for using large viewfinders. Although expensive, if you can go this route then the advantages are compelling. Looking through a large viewfinder underwater for the first time can be a magical experience. In any case, try to think about ways to make for a more interesting, dynamic composition as you see the subject in the viewfinder. Without framers getting in the way, more compositional control is possible. Getting at eye-level, for example, is a good way to make your viewing audience feel a closer link with the fish or octopus you are photographing.
Regardless of whether you are using a Nikonos with framers or a housed system with macro lens, adequate light will almost always not be present. A strobe (or two) will be required to expose the subject and bring out the natural colors. With limited depth of field, you also will want to normally photograph at small apertures (f/16, f/22 or f/32) to maximize the image area in focus. A strobe will easily provide sufficient light to do this. With manual exposure control, you will need to determine the appropriate lens aperture for the range of lens magnifications. For example, 1:2 may require f/22 for your strobe and film, whereas 1:6 will need a larger aperture (maybe f/11). Guide numbers are not really all that useful for close distances, so its necessary to determine appropriate apertures with exposure tests using your lens, strobe and desired film. Changing the film speed or switching from 50mm to 100mm will also require aperture adjustments. When using a Nikonos with extension tubes and framers or some other type of close-up kit, you will need to determine appropriate apertures for each one. Regardless of the camera system, the narrow field of view for close-up photography means that you can use a small strobe with limited beam angle. The reduction in size and weight (and cost!) makes for a system thats easier to deal with underwater.
TTL exposure control works quite well for close-up photography and eliminates worrying about determining what aperture is necessary. Use TTL by all means if possible since you will have a higher percentage of proper exposures and can concentrate more on the photography rather than equipment settings. You must still, however, be aware that setting the aperture too small may be beyond the capabilities for your strobe at that distance. Strobes typically indicate when maximum power has been used, a sign that you will need to set a wider aperture. You should strive to set the smallest aperture possible to maximize depth of field.
It certainly is possible to use a single strobe when photographing with a macro lens underwater. Most pros and serious amateurs opt for using a pair of strobes, however. Control of shadow lighting is more precise and you can more easily deal with the effects of backscatter. Articulated strobe arms permit precise positioning of the two strobes. Ideally the second strobe will have ½ to ¼ the power of the main strobe to fill in shadows rather than totally eliminating them. Equal power from both will create an even, flat lighting that looks unnatural. Most of the time you can use a slave as the second strobe. A slave strobe has a sensor that picks up the flash when the main strobe is fired. Since the speed of light is so fast, the slave will fire before the shutter closes. Slaves will only fire reliably when there is sufficient background to reflect light from the main strobe. If you have problems getting the slave to be triggered, then some type of T-connector will be required. This enables two strobes to be connected to the camera, and both are fired when the shutter is released. When using two strobes in manual mode, aperture adjustments may be necessary. If, for example, you double the amount of light on the subject with equal-powered strobes, the aperture will need to be closed down 1 stop. As with a single strobe, TTL exposure enables you to let the camera do the exposure calculations. Ideally you can reduce the output of the second strobe.
Tidepools also offer great opportunities for working with your macro lenses above water. Unlike close-up photography underwater, ambient light will play a major role in making the image. All sorts of photographic subjects present themselves if you carefully examine areas exposed at low tide. Macro lenses in the 50 to 60mm and 90 to 105mm ranges are suitable. Once again, the 100mm lens provides a greater working distance compared to the 50mm, which can be an advantage if close approach is not possible. Tidepools can often appear dominated by brown and dark green colors of seaweeds. It may take some thorough searching to find splashes of color that inspire a photograph. A tripod is necessary if you want to maximize depth of field, which is usually desired for close-ups. Otherwise camera shake will be a major problem and create a fuzzy image. As a general guideline, the slowest hand-held shutter speed for a 50mm lens would be about 1/60 second, while a 100mm lens would require 1/125 second.
Many times, your intended tidepool subject will be bathed in shadows. You may have to wait for an appropriate time or just search for a similar subject with more favorable lighting. A slight haziness from high clouds or fog can help to create a more pleasing, diffuse lighting. The golden light just before sunset is nice for seascape photos, but may not work for close-ups of tidepool life since shadows can be extreme. In situations where your subject has excessive shadow, you can use a flash to provide fill lighting. If available, TTL flash exposure control works best. You can adjust the flash exposure down a bit (anywhere from 1/3 to 1 stop) so that the flash helps to reduce shadows rather than being the dominant light source. The camera exposure should be based on the ambient light from the subject area.
Lenses with focal lengths longer than 200mm enter the realm of telephoto photography. These lenses have no place in underwater photography since the idea is to get as close as possible to the subject. Telephoto lenses permit you to be relatively far away. Even in tropical clear water, a 300mm lens would be useless for capturing images of fish and other shy subjects. Unfortunately you just have to get closer underwater. Above the surface, without the effects that water has on degrading an image, telephoto lenses are a great way to keep your distance while photographing birds, mammals and other creatures that would prefer you stay away.
Whether from shore, in a kayak or boat, or while flying, telephoto photography presents many possibilities in our area. Generally the range from 200mm to 400 or 500mm is most useful. Zoom lenses, such as 100 to 300mm or 200 to 400mm are also handy. Unless you are within 10 to 20 feet of the subject, exposures will be based entirely on ambient light. You will also need to shoot with a fast shutter speed (1/250, 1/500, 1/1000 second) if possible to freeze camera and subject motion. This is particularly important if photographing from a kayak or boat. Motion of the camera is magnified and readily apparent on images made with telephoto lenses. This can be a problem when using an inexpensive telephoto that has a relatively small maximum aperture (like f/4.5 or f/5.6) since the light may not be bright enough for a fast shutter speed. Thats why pros pay thousands of dollars for fast telephotos that may weigh several pounds and take up a whole camera bag. With a cheaper lens you either have to wait for more light, sacrifice and use a slower shutter speed, or use a faster film. For exposure control you can set the mode to aperture priority with the lens wide open. This will guarantee selection of the fastest possible shutter speed for the situation. Otherwise use shutter priority and set to a fast speed. Telephoto lenses also have a narrow depth of field compared to shorter focal lengths for a given distance. Heres where autofocus lenses can make a big difference and really help when either the subject is moving or you are bouncing around in a kayak.