I use Olympus equipment...currently an E-Volt 620 body and a Zuiko (Olympus) 35mm macro lens. The Olympus uses a sensor that is 1/2 the size of a 35mm frame, and is therefore the equivalent of a 70 mm lens. I am very happy with the camera (probably the best digital SLR that Olympus has made) and the lens which is tack sharp. Olympus also has a 50 mm macro lens (equivalent to a 100 mm) that is superb and considered an even better lens. But it provides magnification of 1:2 whereas the 35mm gives 1:1. As far as I am concerned, the more magnification I can get, the better. Plus, the 35mm focuses much closer which I prefer for aquarium photography in order to reduce the amount of water between the lens and subject and get me closer to the glass.
For lighting, I just use the on-camera flash—I am a big believer in the KISS principle. I use a clip-on diffuser on the flash which distributes the light better and allows me to focus closer to the subject.
I focus and adjust the exposure manually...keeping the lens stopped down as much as possible to maximize the depth of field.
A few tips:
1. You want to have the glass as clean as possible.
2. You also want to have the camera as close to the glass as you can to minimize reflections on the glass.
3. At the same time you want the critter you are photographing to be as close to the glass as possible. No matter how clean the water looks, there are always suspended particles, so the more water you shoot through, the lower the resolution and contrast will be in the picture. Also, the colour of the pic will be affected by the amount of water you shoot through. The more water, the "colder" the photo will be.
4. The cleaner the water the better, of course. For really serious photography I would use a tank with no water movement at all to minimize the amout of debris in the water. I don't bother to turn off my filters in my tank these days though.
5. Focus really carefully...the eye of the critter needs to be in focus or the photo won't work.
Good luck!
EC
