Linhof Filter to Wratten or ? conversion

[Wsufans]

My Linhof came with a set of Linhof filters. There is a green, yellow and dark red all labeled as 2. In reading Ansel Adams books he talks mostly about what I think are Wratten filters or some other seemingly standard numbering system. Plus one "filter" with no glass marked "O". I have seen a blue one on ebay and may someday add one to the collection but...

So the question is how do they relate? Or do I just take a wild guess and wing it then shoot some B&W film and see how it turns out. I will probably do this anyway but...

**PRO**

[Liquid Artist]

Just say that a red filter lightens reds, the same as yellow, green, etc.

However Red will increase contrast in skies substantially, orange a little less, and yellow even less.
just experiment from there.

Oh, the film also has an effect. For examply Kodak T-max 100 appears to have a reddish dye. Basing that from the colour it turns my processor.

[blueribbontea]

No need to take a wild guess. Just make an exposure for each using the filter factors you find in Adams book, assuming the dark red is a 25, for example and that the yellow is a K2. Then you are making an "educated guess" and if the exposure turns out correctly you have verified that the Linhof filters correspond to the Wrattens. Finding the right filter factor is all you need to do.

[Wsufans]

OK. I was thinking the red one marked 2 may be a 25 but was looking for an independent double check opinion. Photos taken with it seem to have similar characteristics I see in Ansel's book. I have also been doing a bunch more internet searching and found a couple of sources that show the filter color and relate it to a specific Wratten number. So I am trying to train my head and eyes to the filer and result but also so I can write it down a bit more uniform. If I post a photo and say I used the Linhof 2 red folks may not exactly know that but if I say #25 more will understand.

I may also take those filters down to the local camera shop and compare them with similar they have in stock to get a good cross reference.

[Wsufans]

Thanks for the feedback. But does anyone know how many filters that Linhof made available? Taking to another Linhof owner today he seemed to think that the one with no glass and "O" might have been a ND filter.