vignetting on a 90

[Jim Rice]

I'm being driven crazy by what I assume is mechanical vignetting with my 90/6.8 Caltar II-N (grandagon) using a B+W 72mm non-slimline polarizer and 67>72 step-up ring when using moderate swing. Would a 67 slimline help, or am I just running out of coverage? The dark corners are pretty sharp in cut-off. Thanks,

-j

[Ernest Purdum]

How about taking all the gadgets off, and seeing if you still have the problem?

[Brian Ellis]

I'd guess that it isn't a coverage problem though it's hard to say without know what movements you're using. But more likely it's the combination of step up ring and filter that's causing the problem, especially when the filter is a polarizer (wider than most other filters) and has a diameter 5mm greater than the lens.

[Leonard Evens]

My 90 mm f/6.8 Grandagon has no coverage problems. I use fairly extensive movements. there is some loss of illumination at the edges, but it is gradual rather than a sudden cut-off.

[Jim Rice]

Any thoughts on the slimline?