Chossing a CPL

[BrianA61]

In need to always feel I have to improve my photos, I'm looking for input as to what type of CPL to buy. It will mainly be used on my 24-105 and my 17-40 lenses. I'm also debating on whether to just use it as a standard "lens protector" kind of like I use my UV filter for now. Question is, what is the best for a reasonable price? Thin, low profile for wide angle lenses? Multicoated? Brands recommended? I haven't used a CPL since my film days of photography so I'm relying on all of you experts on this forum.

[Mike Buckley]

It's too expensive to use polarizers as protectors of your lenses. As for the shortest focal length of your zooms, you won't want to use the polarizer if the scene includes a blue sky due to the negative effects. If you're using the shortest focal lengths and not including the sky, the polarizer can be very helpful. Definitely use a multi-coated polarizer. Sorry, but I'm not qualified to recommend brands.

[Manfred M]

I have a number of cpl filters and I do use them in place of a clear protective filter when I shoot outdoors. Most are basic multi-coated Tiffen ones. I have one expensive B+H MIRC Kaesemann that is used for tricky lighting. I have a couple of large sizes for the Sigma 150-500mm lens and a large 105mm that I use with my Lee filters.

Outdoor shooting usually means these are on the lenses so I don't waste time swapping them out. I sometimes use them to darken the sky, but generally for glare /reflection reduction in all kinds of weather.

[rpcrowe]

I use either a B+W CPL or a multi coated Hoya. I won't touch the el-cheapo type of filter.

I once had a Moose Peterson style CPL filter which combined a CPL with a warming filter. While this was fine for film work, the DSLR would counteract the warming filter. Although, when shooting in RAW. it was easy enough to get a correct (pleasing) white balance when using this filter SOOC images tended to look IMO a bit muddy.

It depends on what type of camera you are using whether you need a slim-line CPL. You certainly do not need one even on your 17-40L if you are shooting with a crop camera. You "might" get by with using a standard filter even if you are shooting full frame but, I don't know about that since I shoot only with crop format cameras.

As far as using the CPL as a "protective" filter; you certainly don't don't need any additional filter if you are using a CPL. However, using a CPL all the time can be counter productive - not only because of problems with wide lenses but because you lose about a stop and a half to two stops of light with the CPL.

OTOH, the CPL has many advantages, too numerous to mention...

[BrianA61]

I'm shooting a FF Canon 5D2 with those two lenses and thought I read somewhere that a slim line would work better. Thanks for everyone's info on this.

[Manfred M]

I'm shooting a FF Canon 5D2 with those two lenses and thought I read somewhere that a slim line would work better. Thanks for everyone's info on this.

The main problem with slim lines is that they tend to not work with lens caps and can be a problem to remove. The only time you really need them is with some wide angle lenses where they reduce or eliminate vignetting.

[Mike Buckley]

The only time you really need them is with some wide angle lenses where they reduce or eliminate vignetting.

Yes, but when have those situations, your really do need them.

[John 2]

I would only add two thoughts to those already offered. A CPL works best with the light at right angle to the lens. As the light angle changes from this position, so the effect of the CPL reduces. As a result, for a landscape using a WA lens, you will get a progressive change in colour saturation across the image, usually most apparent in the sky. It is of course still useful for killing reflections with a WA lens. The second thought is that unlike a lens protection filter/UV filter, you lose between 1 and 1.5 stops worth of light through a CPL. There are a number of good filter reviews on the internet based on lab testing but I agree with Richard, when it comes to a CPL, avoid the cheapies.

[IzzieK]

The problem with filters for me whether it is a CP or not, is that I forget to remove them when I finished using the camera, so using it with outdoor shots then coming inside, it is a strange feeling why I sometimes have a hard time sorting out why I am using an F number higher...

[Mike Buckley]

The problem with filters for me whether it is a CP or not, is that I forget to remove them when I finished using the camera

I also suffer from that disease.

[DanK]

Definitely multi-coated. That is the single most important thing.

The main problem with slim lines is that they tend to not work with lens caps and can be a problem to remove.

Depends on the filter. I have both of those two lenses, and for both of them (they are the same filter size) I use a Marumi Super DHG CPL. It is quite slim, but it does hold a lens cap fine. It is a bit harder to get on and off than a wider filter. I had been using Hoyas for years, and most of my filters still are Hoyas, including the CPL I use with my 70-200 f/4. They are fine, although I have had the experience that some others have reported that they are sometimes hard to clean. I started buying Marumis after reading very positive reviews on lenstips.com, which placed them close to B+W, and then finding out that they are generally inexpensive. They are hard to find, but I buy them on line from www.2filters.com.

I don't leave mine on as a protective filter because of the loss of light. For that purpose, I now buy protective filters rather than UV because the UV protection is unnecessary with digital and makes the filter more expensive. The protective filters I have are Marumi and B+W. All my UVs are Hoya. If I need new ones, I will buy Marumi protective filters.

[Manfred M]

A CPL works best with the light at right angle to the lens.

This is true for skies, but not for controlling glare and reflections from non-metallic objects (which is why I usually use a polarizer).

The other issue with skies is that if you use a wide angle lens if that the effect on the polarizer depends on the shooting direction; if the section of sky is wide, the you will introduce an undesirable gradient like effect called "banding".

Much of my outdoor work uses a tripod or is shallow depth of field, so the light loss is either a Non- factor and even an advantage.

[Mike Buckley]

A CPL works best with the light at right angle to the lens.

In addition to the clarification that Manfred explained, I'll also add that a polarizer has the most effect on a blue sky, which is not always the best effect, when the sun is both at a right angle to the lens and close to the horizon.

[rpcrowe]

Another thought... Many photographers tend to "over-polarize" their images, in that they turn the CPL until the sky is at its darkest. While this looks great for some images, it doesn't look great with all images. I would try polarizing to the greatest degree and then once that is achieved, back off the CPL just a bit to reduce the polarization just a TAD. Sometimes that looks more natural and IMO pleasing...

One advantage of a CPL when shooting landscapes is that it will darken the sky; the amount depending on the angle of the sun with the greatest polarization being when the sun is at right angles to the direction you are pointing your camera. This darkening of the sky will sometimes reduce or eliminate the need for shooting with a GND filter; which is most often used to reduce the brightness of the sky. The darkening of the sky will accentuate the clouds if there are any clouds in the sky...

Other benefits, besides darkening skies is that very often foliage is more saturated with a CPL because the reflection of the moisture on the leaves is reduced. Additionally, rocks are more vivid in color because of reduction or elimination of the glare from the sun off the rocks. This is definitely noticeable when shooting in an area such as our Desert Southwest; especially the reddish rocks of Utah. Turning the CPL when viewing he red rocks of Utah sometimes takes my breath away...



I have not touched all the uses for the CPL filter but here is one more. The CPL will occasionally help penetrate smog or fog because it can reduce/eliminate the reflection on the water and solid particulates in the air. I have not noticed any improvement in the reduction of the heat waves which are sometimes detrimental to landscape photography.

Finally, I don't use my CPL when shooting images for an HDR composite because of uneven polarization from the different shots...

If I had no other filter, the CPL would be one of my first purchases. IMO, it is more valuable (to me) than a ND or GND filter.

[BrianA61]

Thanks everyone, for all the valued input. I will do a little research and find one that suits my needs and won't break the bank.