how to record a full image circle on 4x5

[Peter Gomena]

I recently purchased an old, uncoated 75mm Schneider Radionar (triplet design) that had been separated from a Balda 6x6 folder. It makes a very nice circle on 4x5. Interestingly, the circle gets smaller as the lens is stopped down. I think that is an effect of the edge of the circle coming into focus.

[wthaler]

thank you all for your for input an ideas.

biogon might be a rather luxurious option.

I will get now a Xenar 75/3,5 on a Compur, a rather rare combination I think, it has a 85mm circle according to the schneiders website, it was the standard lens for Rolleicord, that sounds nice to me and I will see how it works out.

wolfgang

[Jac@stafford.net]

biogon might be a rather luxurious option.

Do it right the first time or pay twice to realize the solution. Large format is not for the casual enthusiast.

[wthaler]

Maybe that Radionar is more or less the same as then the Xenar.

[jose angel]

Has somebody any idea or experience with this type of experiment?

I have just recall that I did something similar, but the other way around; I took a full image on film, but I printed it on paper using a smaller format enlarging`lens. So I got a circular image, but on the paper.

[Jac@stafford.net]

I have just recall that I did something similar, but the other way around; I took a full image on film, but I printed it on paper using a smaller format enlarging`lens. So I got a circular image, but on the paper.

For real?

[Steve Goldstein]

A fellow I know put a 30mm Arsat onto an old Speed-Graphic body.

http://www.half-fast.com/

[sun of sand]

many raptar enlarging lenses will actually nearly cover 4x5
"illuminate" with some mush towards corners
even 75mm
90 and 91mm enalrging raptars on 4x5 are at least better than say a holga lens.


I've always wondered what the differences are between these type of enlarging lenses that appear much like rangefinder lenses from the same company only on a barrel

I've hacked a few raptars and ektar enlarging lenses onto digital and they've been quite ok


anyway




I think photos framed by an oval are very nice
don't see it too often
too romantic i guess

[Andy Eads]

With some modification (removing the lens shade petals), the 37mm Mamiya Fish Eye for the RB 67 makes a wonderful circular image on 4x5. I used this configuration to photograph the interior of a nuclear reactor many moons ago. I bought a lens mount (repair part) and afixed it to a Linhof Kardan lens board on the Linhof camera. We made 40" prints with very good sharpness.

[Emmanuel BIGLER]

I've always wondered what the differences are between these type of enlarging lenses that appear much like rangefinder lenses from the same company only on a barrel

Hello from France
Actually some tessar or triplet designs or dialyte (4/4) symmetric lenses were used both as taking lenses and enlarging lenses.
The Apo Ronar (4/4) can be used as a taking lens or as en enlarging lens. As an enlarging lens its only practical limitatation (outside the limit of the image circle) is the modest aperture of f/9 to be compared to f/5.6 or f/4 for some modern enlarging lenses.
Hasselblad had on its catalogue a mounting ring named lens mounting flange, you could use your Hasselblad taking lens as an enlarging lens by mounting this flange to your enlarger head and attaching the lens bayonet to the flange.

Some Boyer lenses, according to Dan Fromm, are not precisely identified as being taking or enlarging lenses.
http://www.galerie-photo.com/boyer-lens-optic.html

QUOTING D.W.F :
Taking lens or enlarging lens? Boyer sold Topaz and Tessar type Saphir lenses as taking lenses and as enlarging lenses. In addition, they sold plasmat type Saphir B and BX lenses exclusively as enlarging lenses. A Rolyn Optics sales brochure asserts that “Boyer are the first optical manufacturers to mass-produce lenses specially computed for photographic enlarging,” so DF found it reasonable to expect lenses Boyer sold for enlarging to perform poorly as taking lenses at distance. EB, however, reports that between 1935 and 1960 only special objectives, usually with name ending in “-B,” were specially computed for enlarging. In the Topaz and Tessar type Saphir lines taking and enlarging lenses were identical; Saphir BX lenses are identical to Zircon taking lenses. Only Saphir Bs were computed especially for enlarging; EB says they were optimized for 5x enlargements and were intended to be used at f/11. In the Beryl line, reprographic lenses, including the Emeraude, and taking lenses are identical.


Modern 6-element enlarging lenses delivering very high quality images are optimized for a certain enlargement ratio e.g. between 2X and 10X for example. It means in principle that you'll be able to get good images as a taking lenses provided that you take a picture at magnification ratios between 1/10 and 1/2.

--

And now regarding the project of recording a full image circle delivered by a LF lens, another approach with a lens designed for the 4x5" format is to use 5x7" film like in this DIY project by Gilles Barbier.
The text is in French but the examples of images recorded on a 5x7" film with an old 90mm Schneider-Angulon-Not-Super are self-explanatory.
http://www.galerie-photo.com/barbier-hybis-90.html