I have some old Kodak gel in glass filters and can't find information on a couple. One is a K-1, Wratten #6. It's light yellow and I seem to remember this was a filter for B&W that was simply a lighter version of the K-2 (#8).
The second is a Wratten #49. It's rather dark blue, and I can't find any information on it at all. Does anyone know what it was used for?
Also, does anyone have filter factors for these filters?