Vignetting

I'm having a problem on some of my shots with
vignetting when I use my Canon 5D Mark II camera
body with my Tamron 28-300 zoom lens. I am using
a 58 mm Tiffin Wide Angle Circular Polarizer. To
get the polarizer to fit, I use a 58-62 LUMICON
step up ring. I suspect that the vignetting is
occurring because of the usage of the step up ring.

Cloning out the vignetted areas does not seem to
work. Occasionally I have been able to save such
an image by cropping, but usually when I try this
it takes away a vital part of the composition.

Perhaps the only solution is to buy a new lens that
will be more compatible with the polarizer. Maybe
such a lens would not require a step up ring. I
welcome your suggestions. Thank you.

Cordially,

Robert Dayton

If you have PhotoShop you can correct the vignetting. Filter>Distort>Lens Correction.

Your lens thread is 62mm and your filter is 58mm? That'll do it.

"Perhaps the only solution is to buy a new lens that will be more compatible with the polarizer"

Umm...wouldn't it be a better (and cheaper) solution all the way around to simply buy a polarizer that fits that particular lens?

Thanks for the helpful suggestions, Buck and John.

In the $100 to $150 range is there any particular kind of 62mm thin rimmed wide angle circular polarizer that
someone would recommend? Thank you.

Although the step-down ring and undersized polarizer seem likely culprits with your problem I hope you have verified that it simply isn't light falloff of the lens itself. Have you performed the simple test of shooting the same subject with and without the polarizer on the lens while keeping the focal length and aperture constant? I also assume that you haven't stacked the ring and polarizer on top of a protective clear filter on the lens.

B&H has six thin 62mm circular polarizers from name brands - B+W, Heliopan, and Hoya - ranging in price from $55 to $130

Thanks, Richard, and Buck. I haven't run the test that you described, Richard, but I'll try it.
You're right, Richard. I haven't stacked the ring and polarizer on top of a protective clear filter.

Thanks, Buck, for the brand names and price ranges.