[Karls48 (Karl)]

I have been trying Wratten #25 for Photometry with resulting error of 0.3 magnitude. All brighter stars are saturated when I use this filter but it shows some interesting objects (carbon stars for one) very nicely. Recently I have read article Wratten Filter Photometry by J.E Hoot. http://adsabs.harvard.edu/abs/2002SASS...21...29H
It seems that you can use Wratten #23 and #58 for Photometry and get better then 0.1 magnitude results when those filters are combined with IR blocking filter. I will try it when the clouds clear. Proper Photometry filters are financially beyond my reach.
Another interesting webside is Photometry for dummies http://brucegary.net/dummies/x.htm