2 April 2009

B+W Slim Circular Polarizer (CPL) filter

What is CPL?
  • CPL stands for Circular Polarizer Filter

Why use CPL?
  1. Reduce/illiminates reflection from non-metallic surfaces, eg water, glass-framed pictures, windows etc.
  2. Excludes glare & reflections to produce clearly resolved pictures.
  3. Colours appear brighter & clearer, contrast is strengthen.
  4. Darkens blue sky while increasing color saturation penetrates haze.
How To use a CPL ?
  • simply attach it to the front of your lens just like an ordinary filter
  • Rotate the front rims to get best results (kinda like doing a manual focus thingy)
Why B+W Käsemann CPL?

Polarizing filters make it possible to reduce reflections in cases of oblique light incident on electrically non-conductive surfaces (e.g. glass, plastics, varnish) and increase color saturation.

Circular polarizing filters have the same effect and also prevent incorrect exposure times and autofocus errors of cameras with a beam splitter in the TTL exposure meter or AF beam path).

B+W Käsemann polarizing filters have a very high degree of elimination, are cemented with plano- parallel high-performance glasses, ground to an exact plano-parallel shape and lacquered at the edges as protection against environmental effects.

Warm tone polarizing filters have a correction filter KR ¡.5 or a 8¡ A as a protective glass. They combine both filter effects in only one filter.

In short this B+W CPL Filter is suppose to be better compares to the other brands .... I will do a comparison between B+W CPL and CPL of other brands in another post just to see whether B+W is really able to deliver better results. Today we will just look at the General feature of a CPL.

B+W High Performance Slim CPL

This is how the surface of a CPL filter will looks like

This is the Slim-est version of CPL filter available in the retail market today


Slim or low profile CPL is a must for UWA (Ultra wide angle lenses) to prevent vignetting (the image of the filter rim appearing in the photo that you are taking)

Why Use CPL?

I know you read the explaination already on the top of the post, but for those who do not understand what it means ... here is another way of explaining it ... with photos!

Those who loves to take photographs will often face this problem, you see some nice fishes in the pond/lake and you take out your camera, aim and shoot! Surprisingly your photo will look something like this ....

Sample #1
Photo Taken without CPL Filter

This is the results of the glare/reflection from the water surface being reflected directly to your lens, and you will get blurry, hazy bright photogrpahs like the one above.

Photo Taken with B+W CPL Filter

To eliminates glaring hazy elements from poluting your photographs you need the help of a CPL. If you look at the photo above, you could see that reflections/glares are totally eliminated.


Try taking photographs from inside your car through the windscreen in broad daylight and this is the results that you will probably get ....

Photo Taken without CPL Filter

Since the reflection is from the surface of your windscreen, this could be reduced/eliminated with the help of a CPL like the photo below ...

Photo Taken with B+W CPL Filter

very minimum glare/reflection detected in the above photo.


This sample will be the same as the one above just taken at a different focal distance.

Photo Taken without CPL Filter through the windscreen of a car

Photo Taken with B+W CPL Filter


Another fine example of how CPL can reduce glare/ reflection of glass surface can be seen in the photos below ...

Photo Taken without CPL Filter

Pay close attention to the windscreen surface of the parked gray car and compare it to the photograph below.

Photo Taken with B+W CPL Filter


Glare/ reflection actually comes from most polished/shinny surface not restricted only to glass. For example, the coffee table of a sidewalk cafe

Photo Taken without CPL Filter

In the above photo, you can see that the reflection from the coffee table is actually screwing up your photos.

Photo Taken with B+W CPL Filter

With CPL installed this is the result that you could expect to get, a clear colorful sharp photo thats not affected by glare, haze or reflection as displayed by the photo above.


Apart from being able to reduce or eliminates glare/reflections, CPL filter can also be use to improves and strengthen contrast while increasing color saturation.

Photo Taken without CPL Filter

In the photo above, the sky is kinda flat whitish blue with very strong haze/glare kinda quality. Its kinda difficult to tell apart the sky and the clouds.

Photo Taken with B+W CPL Filter

In this photo you will notice that the sky and the clouds are more well defined, contrast greatly improved and colors saturation also seem to be alot better.

In a Nutshell

If you thinks that hazy, blurr, reflectioned photographs bothers you alot I would recommend that you get hold of a CPL filter. Street Retail price starts from RM50 (approx USD15) deoending on brand and diameter of your lens.


  1. eh quite worth it..

    But getting a dslr just for it isn't lol. I wonder buying just the filter then holding it in front of my old pns can work anot.. xD

  2. ahmog9:29 am

    wah. got sample of leng lui photo taken using CPL ka?

    Liddat, leng lui look even more leng loh. :p

  3. you sold me on the CPL but a pity i am using a point n shoot DSC-T700
    - unable to fit-la.

    wat a pity-wo..

  4. Really good post...i was having problems with the hazy sky when i was talkin pictures now your post just showed me the real use of filters in photography...nice work

  5. i already got myself a CPL but some people say B+W is best??
    whats your suggestion of brand of CPL ??


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