My 7D hates my CPL

I bought a $20 one for my XSi a couple of years ago. Great for wallet sized prints.

gjl711 wrote in post #11643435
Time for me to dust off one of my old mysteries. It happens only on my 100-400 with a CPL mounted. It doesn't matter if it's my cheap CPL or if it's my B+W Kaesemann, they both do the same thing.

The first pic is is using live view, IS turned off as a baseline to how sharp the pic should be. It's a 100% crop of my arbor shot at 1/3200 hand held.

The second pic is the same but using the cameras AF. and the third pic is with IS engaged. It seems as if the CPL does something funny to the IS causing it to oscillate maybe? Whatever it is, it's only on the 100-400 and only when IS is engaged and a CPL mounted.

Very interesting. Thanks for sharing that.

oldvultureface wrote in post #11643454
I bought a $20 one for my XSi a couple of years ago. Great for wallet sized prints.

I hear ya...

Might want to look into a marumi super DHG. Well regarded and relatively inexpensive.

http://www.2filter.com …/marumicirpolar​izers.html

Also, would highly suggest buying from here. Great prices and extremely fast shipping!

Some time ago, I tested some cheap generic circular polarizing filters I'd accumulated and found that some of them skimped on the quarter wavelength layer and were actually passing through more linearly polarized light than circular polarized. This convinced me that cheap circular polarizer weren't really worth it.

Buy cheap, buy twice. Never had any IQ problem with my b+w kaesemann circular polarizer.

Rai33 wrote in post #11645198
Buy cheap, buy twice. Never had any IQ problem with my b+w kaesemann circular polarizer.

The funny thing is that I NEVER buy cheap... Well except this time.