Anyone have a source for the dichroic filters in color heads? I have an Omega Super Chromega D II color head, which was in production for decades and in wide commercial use. I need yellow and magenta only, because I only print black and white VC. I could use the bare filters or the OEM arm/filter assembly. I'm real happy with this 4 X 5 head, fitted into my 5X7 metal Elwood with some cutting of the top casting. I'd like to keep it running, but the yellow filter especially has some visible fading. I see many sources for dichroic filter blanks, but what to specify? These are optical companies and I have no idea what specific yellow and magenta would work in an enlarger for VC. OTOH, any thin glass dichroic filter that could be cut to fit the little windows in the metal holder arm would work. A "stronger" filter than the one used in color heads like the Omega would actually be better, if it was available. Many workers are using gel filters for the extremes of contrast with VC papers since the original dichroic filters are not that strong in filtration and don't produce the maximum the paper is capable of. I'd like to try a commercial dicroic filter if I knew which category to buy. Any ideas? For example, are the filters in color heads additive or subtractive? How is strength of the filter specified? What passband is best for yellow and magenta for VC? Answers here might help a lot of users in the future as enlargers get older and start to fail, with no replacement parts to be had. Thanks, Todd Foster.