Would a camera measuring 4" X 3" fit in this case?
FARO K Yes, it will actually fit a camera larger than that. The camera shown in the ad is 4" x 3" and as you can see it fits quite nicely. I have a larger camera, one that is 4.6" x 3.8" and it still has room to spare.
JOHN M Yes, it would be a tight fit, however.
CLAUDIA G I would get the medium case. My camera is 3x2 and there is just enough room for the camera and for the lens to open all the way. Used it in January while snorkeling and really liked it!