I recently bought a Tokina 12-24 mm f/4 lens with Nikon mount, and I've been quite happy with it's performance so far. I didn't notice any vignetting from any of the photos I've taken so far, but I think my lens hood seems to darken a part of the frame when I use it. I'm sure it's physically blocking out light from a tiny bit of the frame, making it pointless unless I love cropping. Anyway, that's not the problem. I just got a Hoya HMC Multicoated UV filter because it's a cheap way to possibly protect my new lens. I put it on and took a few shots in my room, and that's when I noticed vignetting. I didn't notice it before, but I think I shot at f/8 most of the time. Can someone tell me whether the following photos show an unusual amount of vignetting? ALL the photos were taken with the UV filter on except the very last one to show you that the filter isn't causing any issues.