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Richard Ide
24-Jul-2005, 23:08
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

Joe Smigiel
25-Jul-2005, 01:04
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.

John Cook
25-Jul-2005, 03:58
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.

ADG
25-Jul-2005, 05:37
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

Ted Harris
25-Jul-2005, 07:05
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.

Joe Smigiel
25-Jul-2005, 07:34
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.

tor kviljo
25-Jul-2005, 07:58
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.

Joseph O'Neil
25-Jul-2005, 07:59
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

neil poulsen
25-Jul-2005, 10:29
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.

Richard Ide
25-Jul-2005, 11:42
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

Bob Salomon
25-Jul-2005, 12:13
"ach end of the lens alone is five inches dia"

If all you need is a 5" diameter filter Heliopan makes filters in 127 x 0.75 mm screw-in sizes for many types including ND filters. As 5" is probably the outside diameter Heliopan also makes 122 x 1.0 mm filters as well as 112 x 1.5mm.

Tom Keenan
25-Jul-2005, 19:43
Call the guy at Singh Ray. He'll make whatever you want. Good guy.

Will Strain
25-Jul-2005, 20:00
Lee makes several lines of 2mm filter material intended for architectural lighting applications. Many stock pieces from this line would exceed your stated requirements. I'd check that route.

Richard Ide
25-Jul-2005, 22:40
Thank you all.

You have given me several approaches to the problem. I like the idea of using a heliopan filter but unfortunately the front and rear elements protrude .75" from the housing. I will let you know what works.

regards

Richard