Robert Pierrard , Dec 29, 2011; 03:21 a.m.
Hello,
I've looked through the previous questions regarding image circles, but my question is unfortunately specific.
I can't seem to find any reference to image circle of specific lenses by the manufacturer - I posted the question in another forum regarding smaller format lenses, but the replies there were that the manufacturer doesn't tend to post these details.
I'm specifically interested in the image circle dimensions for:
Schneider Super Angulon XL 58/5.6 for 4X5
Caltar II NC 65/4.5 for 4X5
Nikkor SW 75/4.5 for 4X5
Pentax 45/4 for 6X7cm
and Mamiya RZ ULD 50/4.5 for 6X7.
(I'm also considering the Schneider Super Angulon 47/5.6 for 6X9cm, but I know the image circle to be 123mm from the website.)
The reason for asking is I'm interested in using shift to expose the full image circle over several digital captures using a FX DSLR, and would like to know the amount of exposure (and hence final max size) of any stitched capture I could make.
I plan on mounting the lens on a 4X5 view camera to be able to use the full functionality of shift, etc (may also get into tilt later). I realize this requires light-proofing the camera, and I'm working on fleshing out an adapter to the DSLR for this purpose.
The reason I'm considering the smaller format 6X7cm lenses is mostly that I enjoy wide angle captures, and would prefer fewer exposures be required to attain that wide angle - the range of 80-100* diagonal FOV is my preferred view, at least in this capacity.
If someone could point me in the direction of some nice 6X9 format lenses as a mid-ground between the 6X7cm and 4X5", that may ease some decision making.
With regards to the image circle dimensions, if there is a database for larger format lenses that supplies this information, it would be greatly appreciated.
Thanks very much!
Leigh B. 
, Dec 29, 2011; 03:30 a.m.
Schneider Super Angulon XL 58/5.6 - IC = 166mm @ f/22
Nikkor SW 75/4.5 - IC = 200mm @ f/22
IC specs are unrelated to the intended format.
The datasheets for these lenses are readily available online. Try Google.
No info re the other lenses.
- Leigh
Robert Pierrard , Dec 29, 2011; 04:42 a.m.
Thanks, I hadn't been able to find any details earlier, I suppose as I was looking for smaller format lenses.
Do you know of any datasheet for medium format (67, especially)?
Regarding image circle size, I know it has no bearing on the intended format, but some lenses are designed with larger formats in mind, eg Schneider's XL and XXL series.
Bob Salomon
, Dec 29, 2011; 09:09 a.m.
The image circles as well as MTF, distortion and color curves are all posted on Rodenstock's web site and are easily downloaded.
Basically lenses made for medium format or smaller cameras do not cover much more then the format since the lens and the back are fixed in relation to each other and do not work like a view camera. The only exception are the PC or T/S lenses for these formats that must have a larger circle.
Mike Earussi , Dec 29, 2011; 10:20 a.m.
Having owned the 45mm lens for the 6x7 I can tell you that it covers 6x7 and that's it (and that's at f11).
Michael Briggs 
, Dec 29, 2011; 11:04 a.m.
As Bob posted, Rodenstock has info on current lenses at their website. Schneider has info on current and past LF lenses at their website. There are compilations at http://www.largeformatphotography.info/lenses/. For an older Caltar you may have to deduce the actual manufacturer and look up their specs. Coverage specs were rarely given for camera-dedicated, fixed-position MF lenses since the users didn't need to know this information.
John Shriver 
, Dec 29, 2011; 11:10 a.m.
You will probably be unable to use anywhere near the full image circle stitching with a DSLR, since the lens mount of the camera will start to cast a shadow on the sensor. (Game over.)
Friedemann Pistorius , Dec 29, 2011; 11:58 a.m.
There are two different Super-Angulon 47/5.6 lenses with different image circles:
Super-Angulon 47/5.6, image circle 123mm at f22
Super-Angulon XL 47/5.6, image circle 166mm at f22 (same as the XL 58)
www.schneiderkreuznach.com (Germany) or www. schneideroptics.com (USA)
Consider Fujinon-SW lenses too, outstanding performance (I have a Fujinon-SW 65/5.6, image circle 170mm at f22).
jim jones , Dec 29, 2011; 01:37 p.m.
In addition to the lens mount casting a shadow on the sensor as John noted, mounting the camera to a view camera back will preclude focusing such short focal length lenses on infinity. Perhaps a mount can be improvised to mount the lens directly on the camera. However, there is only a few mm between the rear element of my S-K f/8 65mm lens and a Nikon DSLR lens mount for improvising such an adaptor. It seems simpler to use the coverage of WA lenses by shooting and scanning 4x5 film
Bob Salomon
, Dec 29, 2011; 02:13 p.m.
The diagonal of a 35mm full frame camera is 44mm. So a normal lens is a 44mm lens. Using analog lenses on a view camera with this short a focal length will prove very tricky as you have to position the sensor to be at the flange focal length of the lens to be able to reach infinity. That means that you are going to attach the camera body, probably to a lens board, and that will push the sensor away from the lens.
The FFL of a 47mm SA XL in Copal shutter is 59.1mm so from the rear surface of the shutter to the sensor plane in your camera you must be at 59.1mm to focus at infinity. If you are using the original 47mm SA then the ffl; is 51.6mm. And then you only have a normal lens, with a hot spot. If you want to use the 38mm XL then the ffl is 52.1mm.
On the othe hand the ffl for the Rodenstock 40mm 4.0 HR Digaron-W is 69.5mm, the 28mm HR Digaron-S is 53.1mm and the 23mm is 44.8mm so you can more easily reach infinity with some lenses like these. But doing it with a 35mm SLR would not be the best or easiest way.