Large diameter polarizers

[rbatey]

I'm using a Fuji GX680 for about a year now for architectural work and

love it. What are MF users doing about polarizing filters for the

large diameter lenses? My Fuji lens shade holds 4x4 filters but only

fits on the 150mm lens. I have several lenses ranging in diameters up

to 95mm and while I'm aware that manufacturers like Lee make systems

that hold square filters, I have not seen a solution for polarizers.

Can anyone offer a solution? A friend mentioned a Cromotek system. Has

anybody heard o

[terry_dvorak]

I use screw-in glass polarizers for all sizes up to 95mm (B&H

sells Hoya 95mm polarizers for something like $85; I sprung

years ago for a pricier brand but I'm not sure there's much

difference). My (large-format) lenses that take 95mm filters are

mostly normal to long, so can screw my Lee compendium 4x4

holder-lenshade onto the front of the polarizer without causing

vignetting.

 

For the widest angle lenses (and I believe that with the 680 it's

the widest lenses that use 95mm filters) using an additional

filter holder/lens shade in front of the polarizer could cause

vignetting, so you may not be able to use your 4x4's with the

polarizer unless you hold/tape them on (something I often do on

my LF lenses). Not ideal, but it works fine.

[michael_fox]

I've done two things, depending on how large your lense is and whether or not it's wide angle.

 

 

1) For "normal" or telephoto, Lee makes an excellent holder system with adapter rings for many lens sizes and thread pitches. The people there are excellent to work with. The holder system has a 105mm threaded ring that can be attached so you can screw a normal 105mm polarizer on the front and use in combo with other 4x4 and 4x5 split ND filters.

 

 

2) For "wide angle" I found the 105mm ring would vignette on my 40mm Hassy lens so I went to a 122mm polarizer. The problem is the Lee system doesn't have a ring for that so I had one custom made by S.K. Grimes (www.skgrimes.com) to go on the Lee holder system. This lets me use my 4x5 split NDs in whatever orientation I want plus gives me the ability to turn the polarizer - something that can't be done with square polarizers.

[bob_salomon]

We have open stock on 95 and 105mm Heliopan polarizers in

both regular and slim mounts. Large sizes up to 135mm are

available on special order. These can be ordered from any

camera store but some, like PhotoMark, Ken Hansen, Photo

Habitat, etc. keep Heliopan 95 and 105mm polarizers in stock.

[peter walker]

Hasselblad sell a 93mm screw thread filter for their lens.

 

Also, I recently bought a large polarizing filter in the form of a

square plastic sheet for my Elinchrom flash units. I doubt if it

would work too well in front of a lens though.

[bengt_rehn]

I use the Cromatek 100 system for my Hasselblad. It is a 4x4 (100x100 mm) system with a integrated filterholder and hood. The holder takes a large 100 mm thin polarizer along with two other filters. The system have a large colection of different threaded and bayonet adaptor rings. The system works well with the 50mm Distagon, but I dont know if it will with the 40mm.

[robert_monaghan]

See http://people.smu.edu/rmonagha/bronfilters.html#homebrew

 

lots of low cost large size filter alternatives, including diffraction gratings and optical quality polarizer materials are in sheet form

from sources like edmund scientific (optic div etc.) and make low cost filters possible in larger sizes...

 

some surplus sources for colored filters too, cf surplus shed etc.