High quality large filter
Greetings:
I need an ND1.0 or 2.0 neutral density filter at least 6.5" in diameter, to go in front of a very high quality 150mm f8 lens I am building an 8x10 camera around. The shutter in the lens will only operate at slow manual speeds as it was electrically driven in the enlarger it came from. I am thinking of stripping a couple of 8x10 plates and building a cell filled with dyed liquid if I can't come up with a better solution.
Hoping you can diffract my circle of confusion even further.
thanks, Richard
High quality large filter
Richard,
Last year I custom-ordered a 6" square 3.0 ND #96 wratten gelatin filter from Calumet (1-800-CALUMET or www.calumetphoto.com). As I recall it took about 10 weeks to fill the order and it wasn't cheap...around $140 IIRC. I believe the filter was actually made by Tiffen although it came in the Kodak packaging. They cut these filters from larger sheets so it may be possible to get one that would cover the 6.5" diameter you are after. Since the 3.0 is in less demand than a 1.0 or 2.0, they may be slightly cheaper or perhaps manufactured more often.
My intent is to use the filter in front of a large Verito lens as well as several others and employ an 8.5" square Packard Shutter that has a 5" diameter opening. Like you, I acquired the large lenses first and am building a camera around them.
Hope this helps.
High quality large filter
Forty years ago when I worked in Hollywood, this was a simple job for Harrison & Harrison. A real no-brainer. Just walk in the front door, tell the man waht you needed and Mr. Harrison himself would go in the back room and cut it while you waited.
Sadly, the Harrisons must be long dead and the business absorbed by a mega modern impersonal corporation.
But this still is a search better suited to the cinematography industry than to a still photography store. Do a web search among the Hollywood venders to professional cinematographers. In the movie business time is money: they will have it out to you before lunch.
High quality large filter
Richard
Lee filters do ND gels at a reasonable price and these were ex stock when I needed one to reduce the light output from the transparency hood on my flatbed scanner.
Hope this helps
Regards
High quality large filter
While the Harrisons may be long dead the company is still very much alive and still making custom size filters. AFAIK they don't have a website. The company is in Porterville, CA now. If you are in the UK you can get their products through OpTech.
High quality large filter
Richard,
Another thought: have you considered using sheets of polarizing material cut to size? That would knock 1.25 stops off and would probably be much less expensive than ND filter material. Try Surplus Shed online.
High quality large filter
In addition to advice given by previous posters: Try out surplus-shed at http://www.surplusshed.com/ They sell military surplus stuff, including aerial cameras, filters & lenses. usually, the filters for mapping&survey cameras were supposedly of very high quality & large diametre, so it's worth to check out. Another source not to be missed is tah ND filters used for astronomical refractors: also of very high quality (diffraction & color fringe not acceptable in astro use) & diametres typically 4" & up. You find ad's in "Sky & Telescope". Adorama sell astro-stuff also.
High quality large filter
Go to
www.surplusshed.com
Look up their aerial recon filters. I have about 4 myself. I literally hang the filter off the front of the lnes. Very high quality filters, I bought mine for about $10 each. War surplus, WW2 and Korean war.
Yellow, Orange, red, UV and ND fitlers I have all seen in the past. may not be exactly what you are looking for, but at $10 each, who's gonna complain?
:)
joe
High quality large filter
Why so large? What lens requires a 6.5" filter? Have you thought about placing the filter behing the lens? There are a number of ways to do this. This shouldn't be a problem, especially with your focal length.
Are you building a camera or an enlarger? You say camera, but you speak about an enlarging lens.
High quality large filter
Neil;
I guess my inquiry should have given more detail. This is a Wild enlarging lens that resolves over 400 lpmm. It is the enlarging mate to the Wild Aviogon lens from which Zeiss developed the biogon. The lens shade diameter is over six inches. each end of the lens alone is five inches dia. I have two of these and the other goes on an 8x10 enlarger. I did very large prints when i had my photographic business and want to see what results I can get with this setup and my choice of subject matter.
Richard