No camera wizardry. I just keep getting that spot of light or whatever in the corner. My shit is about as low tech as it gets. No lightmeter, and the lens has always been kind of jacked. The fstop is broken, and is stuck at 1.4, and there is a little play in the lens when I focus, outer part of the lens can moved back and forth a few millimeters. It's a pain in the ass sometimes, but it can make for some neat background blurs, and multipule areas of focus.