I've notice on a few of my shots that there's a unwanted vignette on the bottom left and upper right corners of the frame. I have a Canon 40D and a Tamron 17-50. The instances occur when shooting at 17 and at night...so the exposures are somewhat long, half a second to about 5. I think for a few of the shots I had my lens hood on, so maybe that's the problem? However I shoot during the day....short exposures.....with my lenses hood on with no issue at 17mm. Anyone have an explanation
Examples:
This one's got it pretty bad ^
Examples:
This one's got it pretty bad ^