It's not as simple as just giving you "settings". It's going to depend on what you're taking pictures of (fish, corals, full tank, etc.), your lighting. . .and then your composition. The type of photograph that appeals to me may not appeal to you. That said, you'll first need to understand exposure. As a matter of fact, there's a pretty good book out there called "Understanding Exposure" by Bryan Peterson. You can get by with the automatic settings, but having at least a basic understanding of exposure is critical for tank photos. That said, here are a few hints:
- As already stated, a good, solid tripod is worth its weight in gold. I'll usually handhold for pictures of fish, but everything else I use a tripod.
- For macro pictures, a good macro lens is key. I use the Canon 100mm macro. They have both an image stabilized as well as non image stabilized. Personally, I'd recommend saving yourself around $400, get the non-IS and use it with a tripod. Sigma also makes a very good macro lens (105mm). Both companies make a 50mm macro, but I find the 100mm to be much more versatile. For full tank shots, the Canon 50mm f/1.8 or f/1.4 is a very reasonably priced lens with excellent image quality. The f/1.4 is a bit more expensive, but it's a much better built lens. The f/1.2 I'm sure is an excellent lens, but I don't think it fits any definition of "inexpensive" (lists around $1,400).
- For fish, start with a shutter speed of around 1/200 - 1/250. It will depend on the fish, but this works fairly well for most. It also happens to be the max sync speed for most flashes, but that's another matter.
- Remember your depth of field is very shallow with macro photography. Learn about depth of field and how it is affected by your aperture setting (a.k.a. f-stop). I seldom shoot at anything wider than f/11. Depth of field is going to be your biggest driver for your other settings (i.e. ISO and shutter speed).
- I always start off deciding what aperture I need for the depth of field I want. With moving objects, I'll then sacrifice ISO before shutter speed. With non moving objects (assuming I'm using a tripod), I can keep a low ISO by keeping the shutter open longer.
- In general, turn off all of your pumps, and give it at least half an hour for any detritus to settle. Also, clean your glass. These two steps will save you a lot of time removing spots and blemishes in Photoshop.
- Remove spots and blemishes in Photoshop (or other editing program). It takes a little time, but it's amazing how many people will let these little spots that are inevitably going to show up detract from an otherwise good photo.
Hopefully that helps. The nice part about digital is that experimenting doesn't cost you anything other than time, so once you're able to wrap your mind around the exposure triangle (i.e. ISO, aperture & shutter speed) and the factors affecting depth of field (i.e. aperture and focal length), just experiment and have fun. Then, we can start talking about using flash.
