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 polyester 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 (in addition to the Xenophon)?

[neil_poulsen1]

Depends on the size of your lensboard.

 

<p>

 

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.

 

<p>

 

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.