After my recent paintings of cars done in my studio, someone asked me to comment on the subject of painting from photos. I'll probably open a whole can of worms here, but my opinion is: it's a compromise either way. You lose a lot of information when you take a photo - mostly in the lightest lights and darkest darks, and color too. That's a big con, unless you are familiar with the subject and know how and where to add what you're missing. That said, when you're working from life, you've got a big time constraint, especially outside. In one to two hours, the sun will be in a completely different spot, and your subject will have changed considerably from what it started out looking like. Even with a still life, flowers move or wilt, apples brown, radishes shrink, etc. That's a big con. I can tell you tons of artists who do brilliant work from life, and tons who do equally brilliant work from photos.