[sebberry]

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I have a Tiffen circular polarizer on my DA* 50-135. While it does help to cut down on reflections off the water, etc.. I find that it doesn't really do much for improving the blue of the sky. My polarized sunglasses do a much better job of that, as well as my smaller Hoya filter on the DA 18-55.

Are some filters just not as good as others?

[daacon]

Indeed not all CPL's are created equal. I had a couple of Kenko Pro DIgitial filters and was generally happy with them, however one busted (just came apart !) and the other two I still have are a bear to clean.

On several recommendations here I just purchased some Marumi's from Ebay seller oeccamera . I just received them today, however they appear solid , quite thin, were cheaper than the Kenko Pro Digitial and from all accounts they are easy to clean.

+! for Ebay seller oeccamera international transaction , went USPS and the filters where here within 5 days. Now hopefully they work well (as mentioned several users here recommend them so I am quite condifent).

[RioRico]

Alas, Tiffen doesn't have the highest reputation as a filter-maker. Rather the opposite. And even premium glassmakers have discount lines of lesser quality. Alas, you get what you pay for, usually. Options:

1) Get something cheap and to hell with IQ.
2) Buy odd-lots on eBay and hope for the best.
3) Bite the bullet and get Marumi or Hoya or Kenko.

[bdery]

Just to be sure : it might be a matter of angle relative to the Sun. Try to place the Sun over one of your shoulders and see if the effect is improved. tiffen are not the best but neither are they that bad.

[Ubuntu_user]

Tiffens are not good from my experience or from tests. Check out lenstip.com's test and consensus on polarizer filters.

[JohnX]

I understand that for sky darkening the optimum position is at 90 degrees to the sun. I also understand that CP's are not recommended for use on tele lenses.

Happy to be corrected on one or both of these statements, as I've not tried either of them for myself.

[newarts]

I understand that for sky darkening the optimum position is at 90 degrees to the sun. I also understand that CP's are not recommended for use on tele lenses.

Happy to be corrected on one or both of these statements, as I've not tried either of them for myself.

Both true but you should try your polarizer on a tele lens to check it out. The basic reason for the non-tele wisdom is that any defect on any filter will be magnified in proportion to the focal length of the lens it is on - it just might be ok and is easy enough to check out.

[newarts]

I have a Tiffen circular polarizer on my DA* 50-135. While it does help to cut down on reflections off the water, etc.. I find that it doesn't really do much for improving the blue of the sky. My polarized sunglasses do a much better job of that, as well as my smaller Hoya filter on the DA 18-55.

Are some filters just not as good as others?

Some filters are not as good as others but most should do about the same in darkening the sky.

Test it by looking through it at an lcd screen - at one angle the screen should go totally dark. Check looking both directions as the filter element may have been installed up-side down.

If the lcd screen goes dark at a particular filter angle it is likely that no other filter will do much better.

A lot of haze in the sky can effectively depolarize its light.

[Laurentiu Cristofor]

I have a Tiffen circular polarizer on my DA* 50-135.

What is the exact filter model? Manufacturers produce everything from cheap stuff you get in sets of 3 for $15 to filters with expensive coatings that cost more than some lenses. Yours sounds so bad I have to ask - did you rotate the filter to adjust the polarization effect or did you forget doing that?

[richard balonglong]

Yup. Some polarizers don't polarize well. I have a Cokin polarizer, and it stinks. Yeah, it polarizes but little. And I have a Marumi polarizer and it rocks! Not all polarizing filters are effective. =)

[bdery]

CP's are not recommended for use on tele lenses.

The polarizing effect (for lack of a better term) will be more even with a long focal length, . So I'd say it is more recommended on a tele lens.

[pacerr]

The polarizing effect (for lack of a better term) will be more even with a long focal length, . So I'd say it is more recommended on a tele lens.

I don't recall any particular problem with PLs of good quality on tele lenses until auto-focus bodies became common. The light reduction frustrated many people using slow consumer zooms with AF cameras regardless of focal length.

One work-around solution was to index the filter on the lens then first determine the filter orientation off the lens after focusing followed by an exposure adjustment after installing the PL. Of course that was inconvenient and not popular with the impatient P&S/AE/AF crowd.

H2

[newarts]

A lot of haze in the sky can effectively depolarize its light.

One must be careful when evaluating a polarizer by looking at the sky 90 degrees away from the sun because the extent of polarization can depend on haze. This is evidenced by the fact that light from clouds at 90 degrees to the sun is not polarized. Haze may therefore play a similar depolarizing role.

Therefore to evaluate the effectiveness in blocking polarized light one should use a source of purely polarized light like a laptop's display (preferably in a darkened room).

[Mark Castleman]

I have used Cokin filters since my film days and have been happy with them. I am guessing you are from Canada by your details and, as others have said, water vapor in the air does minimize the sky darkening effect. Since I travel a lot in the Four Corners area I actually have the opposite problem with the sky turning almost black. The old trick of pointing your thumb at the sun and looking at where your fingers sweep will give you a pretty good idea where the maximum effect will be in the sky. The effect with water (and wet leaves) is almost independent of the location of the sun.

[Nass]

You tend to get what you pay for with filters and cheap = bad results. Here's an illustration (not mine).

Aside: Kenko filters are basically Hoya filters: known as Kenko in Japan and Hoya outside.