Very large lens filters ??

[FrancisF]

I have a couple of large lenses for b&w shooting and I do not want to buy filters for each one. I thought that if I just got the largest size, I could use it for the different lenses. They range from 12 inches across to 4 inches. I thought I could just buy some "stained glass" of a good optical quality and build a holder in front of the lens.....or hold it there.

Thoughts? Suggestions ? Sources ?

Thanks!!

[Jody_S]

The only 12" filters I'm aware of are gels for use in theatre lighting. You would most likely have to have a holder custom made, or you might get lucky and find a theatre spot of the right diameter with a gel holder that can be adapted.

[LabRat]

For deep reds, astrophotographer Alan Douglas used to use deep red acrylic cut to size, as the longer wavelengths were not affected by the imperfect flatness...

Many different thin sheet filters can be tried to see if they work, as I think many will for non-critical applications...

Steve K

[FrancisF]

Jody and Steve,

Thanks for the advice and direction

Francis

[petrochemist]

I find lighting gels work reasonably well when I need big filters. So far I've not needed any bigger than 180x180mm but bigger sizes are readily available.
They are more of a pain to mount than normal filters but seem to work fine.