Sirius, the vignetting is the camera. It doesn't happen at all apertures, but I never kept close-enough track of it to remember when it goes away. This whole roll was shot at f16 because iso 400 is just a bit too fast for the top speed of 1/300. I'm looking forward to finishing up the panf that's in it now to get a better idea of how other apertures affect it. I'm thinking this camera might work best with iso 100 film.