I use my photos for painting. For instance there is an upcoming pig art contest *yes there is such a thing* and I am going with the masters art... so I used this photo
and photoshopped it to this
because I want to do Vermeer's Girl with a Pearl Earring... except I am doing Gilt with a pearl Earring. With a copy of the original painting, and this photoshop photo, I came up with this
As you can see, the photo doesn't have to be something good enough to sell, but it helps to start with as good an image as I can get. I can't do much with a pig, though. A pig is a pig is a pig.