Gel filter size?

[Erik Asgeirsson]

I am looking at purchasing the Xenophon gel filter holder from Calumet, but I am at a loss as to which size to purchase. It will be used behind the lens, and I would eventually like to use it with a 90mm lens. Are the 3" gels (or possibly p olyester filters) big enough, or should I consider purchasing the 4"? Also, are there any holders available so I could use the gels on my 35mm camera as well (i n addition to the Xenophon)?

[neil poulsen]

Depends on the size of your lensboard.

I placed a 4" Xenophon holder on the back of a reducing lensboard. This holder is large enough so as to not interfere with using the reduction lensboards, and this single holder meets all my filtration needs from 65mm through 360mm lenses.

One problem that I encountered with this holder is that, while the back of the holder that faces the ground glass is anodized black, it's also a little shiny. 90mm lenses position this holder close enough to the g.g. to cause internal flare. It was easy to tell, because the shape of the flare corresponded to the shape of the holder. I glued some black felt onto the shiny surfaces, and the problem disappeared.