86mm Circular Polarizer

[BurBunny]

George (aka the Sigma "Bigmos" 150-500mm OS) and I are heading back to Antarctica next month. While I hate to cut any of the light coming into the Bigmos, Antarctica literally begs for a CP

Unfortunately, the Bigmos has an 86mm front thread, and I'm having difficulty finding these from the usual sources. HVStar doesn't seem to carry any 86mm CPs, let alone multi-coated. Places like Adorama and B&H have been out of the B&W for quite awhile.

Has anyone used the Sigma EX multi-coated CPs? Any other suggestions I should look at. I don't like to skimp on fileters, but I also don't want to spend $300 on this filter which won't get a lot of use otherwise.

Suggestions on options and locations to purchase?

[BurBunny]

Really? No one's tried a Sigma EX filter yet? No recommendations at all?

[V8Rumble]

Since your crop camera does not use the full element, you can try and use something like a 77mm filter and a 86mm to 77 step-down ring and not get vignetting.

[ed rader]

[quote=V8Rumble;6861423]Since your crop camera does not use the full element, you can try and use something like a 77mm filter and a 86mm to 77 step-down ring and not get vignetting.[/quote]

i have an 82mm hoya pro 1 i may be selling so PM me if you are interested. i also have a step up ring so it can be used on 77mm threads.

ed rader

[Sean]

http://www.bhphotovideo.com/bnh/cont..._86mm&x=62&y=9

These are the ones that B&H have. The heliopans from what I have seen are top notch, except in price. The B+W ones are also good. Lots of multi-coated ones at 86mm. B&H are showing instock on a lot of them as well.

[BurBunny]

Originally Posted by Sean

http://www.bhphotovideo.com/bnh/cont..._86mm&x=62&y=9

These are the ones that B&H have. The heliopans from what I have seen are top notch, except in price. The B+W ones are also good. Lots of multi-coated ones at 86mm. B&H are showing instock on a lot of them as well.

Interesting. Wonder why I didn't get these when I searched for 86mm polarizer. Still, would rather not pay $200+ for this trip if I don't have to... am going to see how much vignetting I get with a step-down ring, and then if need be order an 86mm filter. I do appreciate the link, though, so I can actually find them again if need be, and good to see they have the B+W back in stock, which it wasn't when I searched a few days ago.

[BurBunny]

Not a bad idea, especially for this trip as I will be using it most likely between 200-500 if history is my guide.

Interestingly, the step down rings for 86mm are really rare. There are some rings that step down TO 86mm, and several options for 82mm-77mm, but neither B&H nor Adorama had what I needed. Only one on Amazon, too... which is now on its way to me. For $10 and change, worth a try.

Thanks for helping me see what should have been obvious

[BurBunny]

Update: Just received the step-down ring and it works like a charm! From experiences with underwater add-on lenses and vignetting, I was actually expecting to see entirely black corners cut off by the filter edge. But instead, just a tad corner darkening which is easily fixed by minor levels of lens correction applied in LR. Hooray!

I tested against blue sky (focusing on tree branches in the foreground), at 150mm, 200, 300, 400 and 500mm. I'm presuming that methodology would be most likely to show up any vignetting if it were going to occur?

Thank you again, Ed, for your offer. However, I'm going to stick with the step-down ring at least for this trip and then re-evaluate after more shooting and trials.

[V8Rumble]

What did you step down too? 77mm?

[BurBunny]

Originally Posted by V8Rumble

What did you step down too? 77mm?

Yes. I already had a 77mm for use with several other lenses, so it was natural to at least try that for economy.