bro, just to help you a little on using filters for BW photography:
Y2 (K2) - Wratten #8
A yellow filter, good for landscapes, general outdoor photography and sports. Blocks UV up to 485nm. Increases contrast between sky and clouds. Great as a general B/W filter and works very well with stone and brick etc in full sun. Also used with Ektachrome IR films. Filter factor 2.
Y3 - Wratten #12
An Orange filter, good for landscapes, architecture etc. Darkens sky and increases contrast significantly. Brightens Yellow tones. Blocks UV to 535nm. Also used with Ektachrome IR film. Filter factor 3.
Y0 - Wratten #16
A Yellow Orange filter. Great for Caucasian skin, and clears up skin tones wonderfully, especially freckles. Darkens up skies noticably in landscape shots and produces very good thunderstorm like clouds. Blocks UV to 545nm and can be used with Ektachrome IR film. Filter factor 2.5
R25 (R8) Wratten #25
A dark red filter. Great for landscapes, darkens Violet, Blue and greens. Produces stunning clouds and skies. Ideally suited for mountain and cloud photography. Lightens reds and oranges. Also used for Ektachrome IR film. Blocks UV to 600nm and has a filter factor of 6-8.
X0 (YG2,5) Wratten #550 (from memory)
Yellow-Green filter that's ideally suited for landscapes, creates greater distinctions between hues of green. Also excellent for outdoor portraiture with clean tinted skin tones and accentuated lips (Caucasian skin tones). Filter factor 2.5
X1 - Wratten #11
Green filter that's excellent for meadow and forest seperation in landscape photography. Also good for outdoor portraiture with soft lighting and backlight scenes. Filter factor 4. Can also be used to correct for tungsten light in B/W photography.
source: Ian (
http://forums.clubsnap.org/showthread.php?t=9208&highlight=Tungsten+Filter)