EWTN Catholic Q&A
Question from LC on 11-29-2011:

Is it wrong for me as a husband to have naked pictures of my wife. I am currently in the military and live thousands of miles away from her.

Answer by Fr. Jay Toborowsky on 12-02-2011:

THis is one of those things that is, in itself, not sinful. Thousands of people have posed nude for artists; I find it hard to believe that, somewhere along the way, no one was "recognized" by their friends or family as the subject of a painting (and photography is the painting of modern day).

A few things to ask yourself. Can you guarantee that no one with whom you serve can see the picture(s)? How would you feel about if others were looking at your naked wife? God forbid something should happen to you, but what would happen to the pictures? Finally, what do you do with the picture(s)? If you are using them for fantasy and masturbation, then that would be improper and sinful, and you're better off not having the photo(s).