# Polarizer vs. 25A Red Filter for Black and White



## elemental (Jun 26, 2008)

Last night I received some compensation to make up for an eBay item that had been slightly less than "as described." Said compensation included a circular polarizer filter for the lens that I'm using on my Ricoh manual SLR. I've been meaning to buy and try a 25A filter for this lens, since all the film I shoot is black and white, but after reading up on the polarizer it seems that their functions overlap somewhat (yes, I know that the red filter is for color and the polarizer polarizes). Basically, I am looking to darken my skies and bring out contrast in bright landscape scenes. As I understand it, the red filter will increase contrast and darken the sky, and the polarizer will darken the sky and reduce glare, which will apparently increase contrast as well. I plan on trying both, but would anyone care to comment on the difference between the two for this type of shooting?


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## AndrewG (Jun 26, 2008)

A polarizer has limited use in b&w photography unless you want to reduce reflections and glare; because it functions within the blue area of the spectrum it won't affect a black and white image. They can be used as a stop-gap neutral density filter, however.
Rather than the red filter which is very strong and robs you of several (3) stops I would consider an orange (G) which will still give you good sky/cloud contrast, nice architectural details and flattering skin tones without depriving you of too much light.


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## christopher walrath (Jun 26, 2008)

Polarizer will eliminate glare from non metallic surfaces such as glass and water.

Reds and yellows will increase drama in skies for landscapes and lighten anything that is the same color as the filter, darkening the rest.  25 is a strong filter.  I would start with a red 23 or a yellow first.


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## elemental (Aug 13, 2008)

AndrewG said:


> A polarizer has limited use in b&w photography unless you want to reduce reflections and glare; because it functions within the blue area of the spectrum it won't affect a black and white image. They can be used as a stop-gap neutral density filter, however.




So I've been using the polarizer for a good amount of my outdoor black and white photography, and I can say that it absolutely affects my black and white images. A darkening of the blue area of the spectrum darkens that area on the black and white image- it won't make deeper blues but it'll make deeper grays and reduce overexposure. For landscapes or candids that include skies, the polarizer darkens the skies and reduces glare in the clouds, usually making for better-exposed, more dramatic, and more interesting skies. I'm sure it's a different effect than a red filter (I have an R2 I'm going to start playing with as soon as my 49mm to 52mm step up ring arrives), but the polarizer definitely has an effect on black and white. 

Sorry to bring this back up, but I thought anyone else looking for this info might like the rest of the story.


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