Glass filters vs. plastic drop-in filtersgreenspun.com : LUSENET : Large format photography : One Thread
One of my lenses has a 105mm filter thread on it and i would like to use filters for it. Most of the filters I want are for black and white photography but the price of 105mm new filters are quite pricey! I was looking into the plastic drop-in filters. Are these going to compromise the sharpness of the lens? Any experiances would be greatly appreciated. Thanks. Dave.
-- Dave Anton (firstname.lastname@example.org), July 12, 2000
...sorry, i forgot to add that there isn't a thread on the back of the lens.
-- Dave Anton (email@example.com), July 12, 2000.
Why don't you use gels or polyester, much better IMO. Pat
-- pat krentz (firstname.lastname@example.org), July 12, 2000.
Assuming you mean high end resin filters like those made by HiTech, Lee and (formerly but no more) Sinar, the answer is that you won't see a drop in quality. have you checked into using Series IX glass filters with adapter rings for the various diameter lenses you use?
-- Ellis Vener (email@example.com), July 12, 2000.
I used the series holders on the rear element (it looks like a space alien claw spider thing) and one morning, not having my double espresso, I nearly scratched my rear element. I almost cried. Are thoes things really safe?
-- Dean Lastoria (firstname.lastname@example.org), July 12, 2000.
The high end filters are made from an "optical resin" called CR-39. They have one advantage over polyester filters - they can be placed either in front of or behind a polarizing filter. The polyester filters must be between the polarizer and the film.
The only polyester filters of which I am aware are made by Lee (also sold under Calumet name). They are 100 mm square and would not be wide enough for you.
Lee's standard holder has an adapter ring for lenses with a 105 filter thread, but I don't see how they would avoid vignetting because the filter width is only 100 mm.
I've seen advertisements from Cokin for a new line of resin filters that is 130 mm across. I haven't used them, but they are worth investigating.
Best wishes, Bruce
-- Bruce M. Herman (email@example.com), July 12, 2000.