hi Carlos-
wanna hear something wierd? i almost never check this forum. in fact, i never check this forum... i keep forgetting it's here. the only other time i've been here is after Skipper told me someone asked me a question (the one and only other thread). but today i thought i'd check and see if there were any new posts... and there it was. crazy...
anyhow- there are two things that determine the magnification of any given [point and shoot] camera. one is how long the lens is-- how far does it zoom in. that is the second number in the zoom lens focal length listings-- ie 28-110mm.
the second factor is the minimum focus distance-- sometimes listed as macro range. that's how close the camera/lens can be to the subject and still have it in focus.
the smaller the minimum focus distance/macro range the greater the magnification. and the longer the zoom lens the greater the magnification, given that the minimum focus distance is consistent.
example- compare two lenses- one that is 150mm on the long end, and that can focus on something 10cm away will have more magnification than a lens that is 110mm and can focus 10cm away.
so you'd want to look for the longest lens with the shortest minimum focus distance.
some of these new cameras nowadays have super long lenses- but not all of them will be able to focus at their minimum focus distance when zoomed all the way in. some of them will only focus close at the wide end of the lens, so the magnification is not all that great. sometimes you can find the magnification ratio listed in the specs but often not- so usually it's best to play with the camera in the store first so you can find out firsthand.
for those shots of corals at the back of the tank... not an ideal solution for that. the reason is, you need more zoom and more magnification at the same time and teleconverters (lens attachments that give you more zoom) generally make the minimum focus distance increase too- so you're gaining some magnification but not as much as you'd think.
sorry- wish i had a better easier answer for ya.
but i guarantee if you spend a jillion dollars like i did you'll get good macros
