Quote Originally Posted by elekm View Post
I would take a close look at each of the lens elements, particularly the rear optic and look for a defect or chip.
I will do that, as it might help explain what I'm seeing. It looks mostly just like there's 'stuff' trapped in between the lens elements.

For what it's worth, I can't detect any holes or defects in the shutter or the aperture. It must be lens related since it varies with how the camera is angled with respect to sunlight, and how intense the sun is.