I know a little about cameras and have worked as a photographer and would like to ad some advice if I may.
If you're a beginner and all the technical stuff goes over your head here are a few simple tricks.
- turn all the lights off in your room so only your aquarium lights are on, if you need to add lights above your tank then do so, don't add to the sides or in front
- put a black piece of card, or black material on the back of the tank
- put your point and shoot on sports mode (or fast shutter) to reduce blur
- if you know how to change ISO put it up high, 1600 if you can, just change it back to auto when you are done. What this will do is force your sports mode to tighten aperture to give you the most amount of your tank in focus
- try to avoid using a digital zoom, if you dont know what this is, just don;t zoom in too far, maybe 2/3rds of the way at most
- don't use a flash on your point and shoot camera, it will bounce off the glass and ruin your shot
- if you're shooting with your phone, don't use the flash, you can still get good results by turning off lights in your room
If you know you're way around DSLR's and you get where I'm going with the above list. Here are a few tricks you may or may not know.
- get a macro lens if you can afford one, 60mm for apsc crop or 100mm / full frame
- if you can't afford a macro prime lens then check out a diopter aka close focus lens (search close focus diopter at your gear site) they screw on the front and become a poor mans macro but you will lose longer focus ability and it might be harder to track a moving target
- when you use a macro or a diopter to get in close your dof is going to go crazy shallow. This is a property of shortening focal distance, you can combat this by getting your aperture to f10 or tighter, f16+ if you can. Boost your iso high as you dare and add light, slowing the shutter as slow as you dare can gain you a stop or two of light as well
- if you're shooting flash then get your flash off camera and trigger it either with pocket wizards or a cable, you want to get your flash mounted above the tank where it can't reflect off glass. Get your flash diffused as well, a piece of white translucent paper across the top of the tank can diffuse it nicely. Don't worry about spill light off the paper as it will be negligible after it has bounced around your room. A large diffused source like paper will work better than a gary fong on your speedlite
If you have a question I'll do my best to answer, happy shooting !
a cheap 50mm f1.8 prime lens with a close focus diopter on a lower model aps-c DSLR can create awesome, awesome shots without costing you too much