Tuesday, August 28, 2012

Ultra Large Format - info from my original website

Here is some potentially useful information, for shooters of ultra large format film.  It's an old page that I maintained on my old web site (which is now defunct).
Last Updated: 06/15/05
Ultra Large Format re-entry...
This page documents my experiences with 10x12, 11x14, and 7x17inch Ultra Large Format photography.
I recently traded a lens for a 11x14 Century ultra large format view camera. The camera came with a 10 3/4inch Dagor that should cover the format. Also with the camera came a 10x12inch Korona film back. There are film holders for both formats. The condition was fairly good. The bellows are intact and the wood is in decent condition. The camera has obviously been used. I needed to cement wood shims onto the main mounting block to keep the rear section from flopping about. From years of use, the aluminum cleat had rubbed the guide channels wider than the original design allowed for. Once in place, the shims work very well and the back is now rigid. Additionally, I built an adapter for the 10x12 back to mount onto the 11x14 rear frame. Everything is now ready to go.
Prior to this I picked up a 7x17 Korona ultra large format view camera. Its in fabulous condition. The wood looks like its new. Over the 2004 end of year holiday season I was able to take it out and try my hand at making super large negatives. The camera was very light and useful. In fact, it was a pleasure to use. I more recently took the camera down to the local roundhouse for a few images of old steam locomotives. I can't wait to process the film to see what I have.
The bulk of what follows regards lenses, coverage, and my observations and disappointments in using various lenses on the 10x12, 11x14, and 7x17 inch view cameras.
Optical image circle requirements
Various ULF cameras require lenses that cover the following:
  • 11X14 - 450mm
  • 7X17 - 466mm
  • 8X20 - 540mm
  • 12X20 - 585mm
Lenses that cover 11x14 and 7x17
Looking at photo.net and other resources, here's a list of small light shorter lenses that have been reported to cover 7x17 with sharpness corner to corner. In increasing focal length:
  • 18cm/183mm Zeiss Protar f/18
  • 18cm/183mm Bausch and Lomb Protar Series V f/18 (built under license to Zeiss)
  • 240mm Computar f/9
  • 240mm Germinar-W f/9 (maybe, the corners might get lopped just a little)
  • some 240mm Kowa Graphics
  • 240mm Zeiss Dagor (not the Goerz version)
  • 250mm Kodak Wide Field Ektar f/6.3
  • 270mm Computar f/9
  • 270mm Goerz Dagor
  • 300mm Computar f/9
  • 305mm Schneider GClaron f/9
  • 355mm Schneider GClaron f/9
  • 360mm Fuji A f/10
  • 450mm Fuji C f/12.5
  • 450mm Nikkor M f/9
Here is a list of potentially expensive, large, heavy, hard to find, or old lenses that reportedly cover the 7x17 format:
  • 210mm Schneider Super Angulon
  • 210mm Schneider SuperSymmar XL
  • 300mm Goerz Dagor
  • 300mm Fujinon-A
  • 305mm Germinar-W f/9 (not the APO Germinar version)
  • 355mm Schneider Symmar
  • 360mm Fujinon-W
  • 360mm Germinar-W f/9 (not the APO Germinar version)
Calculations on 7x17 lens coverage The 7x17 format is 178 x 432 mm. A full diagonal is 18.38 inches or 466mm. Here is what various focal length lenses must cover to adequately shoot 7x17 with a usable image circle of 466mm.
  • 300mm lens - 74 degrees
  • 250mm lens - 85 degrees
  • 150mm lens - 114 degrees
Example: If I've done the math correctly, here's the calculation for 150mm coverage on 7x17.
9.19inches (diagonal from center of the format to the corner) divided by 5.9inches (150mm lens length) equals 1.55. The atan of 1.55 is 57 degrees. 2 times 57 degrees to get the full angle equals 114 degrees. I use a 110SS-XL on 8x10. To accomplish this, the lens needs to cover 112degrees. It does this with ease. Its probably a stretch to think the 150SS-Xl mightjust reach 114degrees. Anyways, I will never know. I sold the 150SS-XL.
Obervations on 7x17 lens coverage
There is some question whether an 80 degree lens like the Fujinon 250mm f/6.7 would work or not. One person on the 'net suggested that it would cover. Others said no, it wouldn't. But I purchased the lens anyway in hope that I could use a small modern 250mm lens and avoid having to deal with size and weight of an older optic.
The gent who originally owned my camera used a 250mm Kodak Wide Field Ektar f/6.3. The WFEktar is rated at 80 degrees and is not a wide angle lens. Its a wide field lens. I didn't buy it at first due to a somewhat non-working shutter (Ilex #5) and due to its overall size and weight. But I made a deal for the optic later and it was quickly delivered.
Over a holiday week I took the Korona into the field and tried the Fuji 250mm W f/6.7 lens. I shot at f/45 and focused somewhat near infinity. The subject was probably 50 feet away. After processing the negatives, I can say with direct personal experience that the Fuji does not cover 7x17. There is an arc about one inch from the neg edges where the light falls completely off. This is a little sad as I really like the focal length for the kinds of things I "saw" in 7x17. Well, its back to trying the old Kodak 250mm Wide Field Ektar.
I also picked up a Fuji 250mm SF f/4.5 (soft focus) on rumors that it covered 7x17. Over the same holiday weekend I tried the SF optic too. While it "covers" the format, it "pulls" the image in very unpleasing ways around the edges. It does this to the degree that I doubt I'll use the soft focus lens for anything on 7x17 other than close ups. For soft focus work at subjects around infinity, a person will need to consider a different/longer optic.
Computar Coverage
The coverage of Computar f/9 lenses has been widely discussed. Some people say they cover 95degrees. Is it too good to be true? Seems like it. Here is the reported coverage at f/22:
  • 210mm Computar - 456mm (though some people have tested this at a more realistic 390mm when mounted in a #1Copal shutter, and others have told me that the lens "works on 7x17, but the corners do go soft)
  • 240mm Computar - 523mm
  • 300mm Computar - 655mm
Further information on the camera or images using this format are found at:

No comments: