What kind of a photo size should I be looking for?

[joshky]

I'm looking for a high resolution photo that I can buy creative rights to, to use on the background of my tank to give an illusion of depth. My dimensions are 48" long by 16" high, however I do have a corner overflow so more like 41" long. I can print this off at work no problem so that's no issue. The biggest I've seen so far is 4368 × 2911 px, would that size work or would it stretch too much?

Also if anyone knows, is there something out there I can spray it with to make it water proof?

edit:

I just found this one which might work, it's 4900 x 3300 px.
http://www.istockphoto.com/photo/dead-reef-4836217?st=404d9ca

 

[BlueCorn]

Pixels don't directly translate to printed size. On screen yes, but on paper it comes down to dots per inch (DPI)

You'll want to find a print size that is close to your tank size and go from there.

 

[joshky]

Yeah I found a neat calculator actually, thank you.

http://auctionrepair.com/pixels.html

Now just to find the right photo in a decent enough DPI, I suppose it really doesn't have to be high quality considering vision blurs the further you look out into the ocean. I will also have to do some photo manipulation I imagine, as everything I have found thus far isn't quite what I want, just shy in some cases.