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Unread 09/04/2004, 09:49 AM   #2
gregr
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Join Date: Oct 2001
Location: Studio City, Ca
Posts: 7,011
this a short article covering basic camera settings for aquarium photography.
if you have anything to add please do!
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Full Tank Photos:

Full tank shots are best done from a tripod. Not only will the images be sharper, but it will also be much easier to frame a shot that is straight and level.
Aperture priority is good for this type of shot, and an aperture of f4-f5.6 is a good starting point. Keep an eye on the camera's shutter speed - if it goes below 1/30 or so, a bigger aperture (smaller f-stop number) may be necessary, or the ISO may need to be raised. Ideally, the shutter speed will be 1/60 or higher in order to keep moving fish or swaying corals in sharp focus.

Aquarium lighting is rarely soft and even. It can be very difficult to achieve an even exposure throughout the tank, so exposure compensation is often necessary to prevent overexposure at the top of the tank where the lighting is brightest. If the images are too bright, then set negative exposure compensation - start with the smallest increment (usually 1/3 stop) and keep experimenting until the exposure is right. Try different apertures as well as compensation.

Fish Photography:

Fish photos require a different technique. Since the subjects are moving, a reasonably fast shutter speed should be used. A shutter speed of 1/90 may work, but even faster is better. I typically use aperture priority for any photography that does not use a flash. As a starting point, use the biggest aperture (usually around f2.8) that the camera allows to ensure the fastest possible shutter speed.
I like to use a flash for photographing fishes. When using a flash, be sure to keep the camera aimed slightly downward to keep the flash from bouncing off the front of the aquarium and sending it back into the lens. For flash photography I recommend using a manual exposure mode. Try experimenting with different settings, but a good starting point is f4 and 1/60. Flash exposure compensation may sometimes be necessary. Take a test picture and determine if it's too bright or too dark. If it's too bright, then set negative flash exposure compensation (reduce the flash output); if it's too dark, positive compensation may need to be applied. Again, start with the minimum increment and go from there. Adjusting the ISO may help, but remember that the higher the ISO, the grainier the picture will be.

Close-ups:

Close-up shots are usually the ultimate goal of the aquarium photographer. When shooting close-ups, keep in mind that as the camera is moved closer to the subject, the depth of field decreases. Depth of field can be described as the area of the image that appears in focus. To achieve good depth of field on close-ups, use a small aperture, but remember to double the shutter speed each time the aperture is cut in half. For example, if an accurate exposure is f4 at 1/60, to get more depth of field would require f5.6 (one stop difference) and a shutter speed of 1/30. This keeps a consistent amount of light hitting the sensor/film. To add even more depth of field a setting of f8 could be used, but the shutter speed will then be reduced to 1/15. It's easy to see the compromise here - if anything is moving (polyps swaying in the current, for instance), it will be blurry at slower shutter speeds because any moving object will change position while the shutter is open. A tripod is extremely helpful for this kind of photography because of the slow shutter speeds involved and the likelihood that the camera may move, causing a reduction in image sharpness.
Flash can also be effectively used for close-ups. The added light will help to achieve greater depth of field and to freeze any movement. The same techniques applied to fish photography (with a flash) also apply to close-ups, except the emphasis for close-up shots is on depth of field as opposed to fast shutter speeds.

Technique is everything when it comes to macrophotography. Small apertures are ideal for close-ups, but finding the best compromise in terms of depth of field and shutter speed is a matter of judgment borne of experience.

White Balance:

Accurately reproducing colors with a photograph can be a challenge, especially when the aquarium is equipped with 20K Kelvin bulbs. As camera technology improves, color accuracy from automatic white balance settings are improving, but it may still be necessary to set the white balance manually. Consult the camera's manual on this process if your camera has this option.

Manual white balance adjustment involves placing something white under the aquarium lighting and pointing the camera at the white area while pressing a button or sequence of buttons on the camera. Once the camera sees what the tank lighting looks like on the white surface, it can adjust itself so that all colors are reproduced accurately. Even with a manually set white balance, however, it may still be necessary to adjust some settings in an image editing program to achieve adequate accuracy. When using a flash, auto white balance is usually very accurate. White balancing is another area where experimenting with different settings may be required to achieve the best results.



Last edited by gregr; 09/04/2004 at 04:27 PM.
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