Justin...I to believe it was the filter causing vignetting. To check this set the zoom on the widest (28mm) setting. Stop down the lens as far as it will go (f22 or so. Then look through your camera as it is pointed at the blue sky (not at the sun!). If it is your filter vignetting the corners of the viewfinder will appear to be cutoff or much darker then the center...jim(posted 8545 days ago)