Which CPL to buy

As another practical matter, apart from the negative effects of adding glass to the light path, is when you stack filters, and especially brass ringed filters like the B+W, they tend to bind together and can be quite a bother to seperate at times.

Actually, the conventional wisdom is if you stack aluminum, they bind for two reasons:
1) during removal too much pressure squeezing distorts the ring and causes more binding, and
2) aluminum self 'bonds' to aluminum.

Brass rings better resist distortion, and they also do not bind to aluminum (as well as aluminum binds to aluminum).

I have reached the point where I frame my shots for cropping . I have not cropped a shot in almost 2 years for vignetting
I don't like glare / flare and often use the hoods from the 10-22 , 17-55 and the 35-350 on whatever lens I have on .
Now that I have the 70-200 , I will have at least 4 hoods to choose from [Last count , there were 8 hoods for 77mm canons] 4 different types of rubber hoods and I hate metal hoods .
Before / maybe to late you get upset - ever had a flash from someone else's camera ruin a shot ?
A kid throw a rock in a pond or a duck decide to take off ?
I have even been close to roads where the reflection of sun off windshields throw a spear thru shot . I am not good enough not to think about .
The filters I normally carry are @ least 1 spare UV 33 KSM CPL's 2 ND 3's -
82A [cuts down on red in morning and evening]
a haze
a warming
a cooling
and a soft center
They are all screwed together with filter stackers on each end
Yes I carry 3 filter wrenches
These are always in the bag , others are taken on a need basis
I have but don't like lee type

Wilt wrote in post #11635476
Actually, the conventional wisdom is if you stack aluminum, they bind for two reasons:
1) during removal too much pressure squeezing distorts the ring and causes more binding, and
2) aluminum self 'bonds' to aluminum.

Brass rings better resist distortion, and they also do not bind to aluminum (as well as aluminum binds to aluminum).

In the past, when I mounted my KSM CPL, I would just through it onto the B+W UV filter already in place. If I so much as gave it an extra nanometer of turn after it was softly seated it would require an act of God to get it off of there - usually bringing the UV filter with it. Once at a garden, a photog friend noticed me bearing down on the filter and remarked something along the lines of, "and that's why you got to be careful with stacking brass." Apparently it was common problem. I chalked it up to something about a brass surface meeting another brass surface, eachi biting into the other. Perhaps some synergystic gripping effect that doesn't happen with brass on aluminum or plastic, where the aluminum or plastics don't "bite back." Hell if I know, though.

I don't know about conventional wisdom, but that Kaesemann became all but welded to the UV filter with very little effort. (It doesn't help when you have such little space to grip the KSM, either...)

Regardless, to the OP, saving your money and going for the Kaesseman is probably the best answer, especially if you care about quality.

Wilt, are you sure Kaesemanns don't have extra coating that benefit optics, apart from weathersealing coatings, or some other component to their construction (foils) that differentiated them from standard c-pols optically? I thought I read somewhere (Schneider's website perhaps?) that KSM was something more than just edge sealing.

Indecent Exposure wrote in post #11636644
Wilt, are you sure Kaessemans dont' have extra coating that benefit optics, apart from weathersealing coatings? I thought I read somewhere they did (Schneider's website perhaps).

Schneider information claims that the Kaesemann polarizing filter element is better than a non-Kaesemann, but they fail to state qualitatively or quantatively how that 'better' will manifest itself. From Schneider..."Kaesemann pol filters are comprised of particularly ultra-efficient, neutral-color polarization films between specially ground and polished cover glass."

There was an exhaustive comparison of filters done not too long ago that made the rounds and I recall KSMs scoring different across some optic metrics than non-KSMs from B+W. I need to find that report anyway. Would be good to have quick reference to it.

Off to Google.

This looks like it:

Lenstip's Polarizing Filter Test. Note the "Transmission and Extinction Coefficient" for the KSM and non-KSM 72mm C-Pols in the test. It seems there is something at play here apart from weathersealing.

Looking over Schneider's website, though, it doesn't look like we'll get any specifics as to the coatings, but these objective light tests at least suggest upgrading to the KSM model may yield some optical benefit. Of course, the slim non-KSM does very well against the KSM, but the slim KSM does the best of all (apart from the KSM that was diqualified, of course). The slim KSM bests the slim non-KSM in every transmission catagory tested.

Indecent Exposure wrote in post #11636611
If I so much as gave it an extra nanometer of turn after it was softly seated it would require an act of God to get it off of there - usually bringing the UV filter with it. Once at a garden, a photog friend noticed me bearing down on the filter and remarked something along the lines of, "and that's why you got to be careful with stacking brass." Apparently it was common problem. I chalked it up to something about a brass surface meeting another brass surface, eachi biting into the other. Perhaps some synergystic gripping effect that doesn't happen with brass on aluminum or plastic, where the aluminum or plastics don't "bite back." Hell if I know, though.

Interesting to hear about two brass rings binding. Not too surprising, given the 'bonding' of similar metals, such as aluminum.

Cant go past tthe Hoya HD DIGITAL CPL....Its a great CPL because it uses 1 stop less of light than normal CPL filters! I have it now on my 24-70l on a semi permanant basis. I only take it off for low light shots its that adaptable to day conditions giving thatit only takes away 1 stop of light

A review can be seen here

http://www.kenrockwell​.com/hoya/hd-filters.htm

Ah, good to know. I'll remember to take off my UV filter then. I've never used a CPL so I wasn't sure if all of them had the rotation ring or not. I only have one friend who is into photography but he doesn't use CPLs so I have never seen one in person. D: Sorry. I guess I'll have to practice adjusting in at home just to get the feel for it so I don't end up dropping it on the field.

I never use hoods and have yet to have a problem but I got a used 10-22 and it came with a Hoya UV filter and a hood so I'll try and remember to bring the hood in case I need it. Thanks again for all the help guys and gals. (: