Some filters I use only come in gel, and gels are so expensive that I want to find a way to make them last. Does anyone know of someone who will mount gel filters in glass?

-- William Marderness (wmarderness@hotmail.com), February 25, 2002

Answers

B+W sells them already mounted.

-- Wayne DeWitt (wdewitt@snip.net), February 25, 2002.

I want a 44a. B+W and Tiffen don't make it.

-- William Marderness (wmarderness@hotmail.com), February 25, 2002.

William, A good biology supply house should be able to supply you with whatever you'll need for mounting your gel filters in glass slides, but the glass will probably be uncoated. Have you considered using the cardboard filter frames that Calumet offers? They do a good job of prolonging polyester filters and are compatible with wratten gelatin filters. Best of all, they won't break like glass when your pack mule steps on them. Good Luck!

-- John Kasaian (www.kasai9@aol.com), February 26, 2002.

Gel filters laminated between glass will continue to shift/fade due to exposure to light as well as temperature. That is why Heliopan does not make them. They will shift just sitting in the drawer waiting to be sold. This happened to an extremely large order of glass sandwiched gels sold by Kiron (the B+W distributor prior to us) on a sale to a very large mid west dealer several years ago.

Gels are not stable new, nor in use, nor in glass. The only advantage to glass is protection against mechanical damage.

This is related to wratten gels. Not plastic ones

-- Bob Salomon (bob@hpmarketingcorp.com), February 26, 2002.

If Heliopan (or anyone else) made a glass 44A filter, I would buy it, but no one makes it. It is a gel or nothing.

-- William Marderness (wmarderness@hotmail.com), February 26, 2002.

Bill - How critical is the application (are you doing pseudo-ortho?)? Have you checked the B+W#470 - either alone or with a #420 or #021?

-- Wayne DeWitt (wdewitt@snip.net), February 26, 2002.

Thanks, but I already own a B+W 470. I like it, but the 44A is significantly stronger.

-- William Marderness (wmarderness@hotmail.com), February 27, 2002.

You might have to do the job of mounting between glass yourself. When glass-mounted gels were readily available, they were just a standard gel glued between two pieces of optical quality glass with Canada Balsalm. A better alternative to Canada balsalm these days might be UV curing glass bond adhesive, but try this acrylic based adhesive on a small piece of gel filter first, there might be an adverse reaction!
I've recently used glass bond myself to repair a small achromat doublet that had cracked apart. A very successful repair, by the way, and quite easy to do.

The 44a is listed as a light blue-green filter. You should be able to substitute a cyan CC filter for it, surely?
You might have better luck trying to find, say, a 50 Cyan CC filter in resin.

For your further information; I notice that the official distributer (and manufacturer) of Wratten filters, and Kodak's other professional accessories, is now The Tiffen Company LLC.

-- Pete Andrews (p.l.andrews@bham.ac.uk), February 27, 2002.