I'm reading through this thread and have some questions about the B+W line of 82mm Clear filters, of which I see three on B&H:
(A) B+W 82mm XS-Pro Clear MRC-Nano 007 [$121.95]
(B) B+W 82mm 007M Clear MRC Filter [$100.66]
(C) B+W 82mm Clear Slim MRC 007M filter [$170]
My questions are:
1) I know that (C) is "thin." I know that (B) is "standard." But what is (A), thin or standard?
2) I see this warning in the item description for (A) on B&H's site:
This filter ring's outside diameter is slightly larger than the actual thread size, and because of this you may be unable to attach the lens manufacturer's bayonet-mounted lens hood to the lens while using this filter. This is dependent on your specific lens and how thick the front rim of the lens is; with thinner, low-profile lenses usually being affected more.Does this lens hood problem affect the 82mm XS-Pro on the 24-70 f/2.8 II? And is this a problem with the 77mm XS-Pro on the 70-200 f/2.8 II?
3) I see people in the thread mentioning a 82mm "F-Pro" filter. Is that referring to (B), or something else entirely? I can't seem to find a mention of "F-Pro" on B&H.
4) Is stacking a circular polarizer filter on top of an existing Clear/UV filter something that people commonly do? Or are you supposed to take off the Clear/UV filter first, then screw on the circular polarizer?
5) Is (A) too thin to stack another filter on top of it?
1) 'A' (XS-Pro) is thin, but has front threads whereas the Slim does not, meaning the standard lens cap doesn't work (it comes with a slip-on). By the numbers, for non-CPL filters: F-Pro (the official name of the 'standard' mount) is 5mm thick, XS-Pro is 3.4mm thick, and Slim is 3mm thick.
2) Ignore the 'warning'. I've got XS-Pro filters in many sizes, no issues with hoods.
3) Yes, F-Pro is 'B'. In addition to XS-Pro and Slim, you may also see Extra-Wide - those have bigger glass to avoid vignetting (e.g., the 77mm EW has 77mm threads but an 82mm filter - those do often cause hood problems).
4) Stacking provides no benefit (other than speed). Conventional wisdom is it hurts IQ, I haven't tested it...but I don't stack unless I'm in a big hurry. I do stack a CPL on an ND, though, to get combined effects.
5) Since 'A' (XS-Pro) is thin but has a front thread, that's the one you want if you're going to stack - a thinner stack means less chance of vignetting. You can't stack another filter onto a Slim filter.