Mamiya 50mm f/6.3 coverage + shutter

[Ivan J. Eberle]

Hi all,

I've had this persistent nagging notion to make a 6x9 remote game cam using one of these legendary Mamiya Press and Universal lenses. Couple of issues come to mind. I'm reasonable sure that it covers at least 6x9-- does the critically sharp circle go even larger? (For any who might wonder why I'm posting about a MF camera lens on the LFF, Mamiya did have a LF sheet and/or Polaroid back for these Universals, is why this question is pertinent.)

Also will need to fit it into a solenoid-operable Prontor-type (self-cocking) shutter. Were Seikosha shutters available in this configuration? Are these 5 bladed aperture shutters or were there variants with more leaves, preferably rounded leaves? Are the lens cell threads and front/rear element spacing compatible with Copal/Prontor/Compur (and if so what size)?

Thanks!

[Sevo]

I've had this persistent nagging notion to make a 6x9 remote game cam using one of these legendary Mamiya Press and Universal lenses. Couple of issues come to mind. I'm reasonable sure that it covers at least 6x9-- does the critically sharp circle go even larger? !

Design wise it seems to owe a lot to small format Biogons - last but not least the fact that its critically sharp circle obviously is the same as its circle of illumination. The latter just about makes it to 6x9 at f/6.3, but does not grow much even when stopped down. At least mine still vignettes the corners of Polaroids (73 x 95mm) when stopped down to maximum. And no, the Mamiya sheet backs come in all varieties of (nominal) 6x9, but nothing beyond that, not even the quarter plate format of the Polaroid backs.

As far as shutters are concerned, the lens comes with an helical-integrated shutter, other than the rest of the Press lenses which are cell mounted into standard shutters. No idea what its size may be, it is not as accessible as the other's shutters and I won't take the lens apart while it is perfect. I guess it might follow a RB67 pattern, and if so, the shutter will be non-standard.

[Jim Galli]

I had a friend who used to hog out the 6X9 backs and make a 6X10 frame with that lens. I don't know if his corners were weak or not

[BarryS]

I can confirm that the 50mm covers 6x9, but I don't think it covers much beyond that. It wasn't offered as an option for the Polaroid 600SE, so that means the coverage is likely less than 2 7/8 x 3 3/4 inches. Don't quote me on this (since I'm not near my Mamiya press gear at the moment), but the 50mm is in a Seikosha #0 and I think the cells might screw directly into Copal/other #0 shutters.

[sanking]

My friend Sam Wang has worked extensively with a home-made camera based on the 50mm Mamiya Press lens. The camera has a 5X7" back and the lens gives a image circle on film that is about 4 1/2" - 4 3/4" in diameter. He has printed some of this work very large, say about 6X-8X, and the image quality on the edges is very impressive.

You can see Sam's work at his website, http://www.samwang.us/. Most of the round images on the site were made with the 50mm Mamiya lens, not sure exactly which ones on the site since he also uses a 4X5 round camera based on a 38mm Biogon. But most of them were made with the Mamiya.

The 50mm Mamiya lens is single coated and needs to be used with a good lens hood to avoid flare in contrasty situations.

Sandy








Hi all,

I've had this persistent nagging notion to make a 6x9 remote game cam using one of these legendary Mamiya Press and Universal lenses. Couple of issues come to mind. I'm reasonable sure that it covers at least 6x9-- does the critically sharp circle go even larger? (For any who might wonder why I'm posting about a MF camera lens on the LFF, Mamiya did have a LF sheet and/or Polaroid back for these Universals, is why this question is pertinent.)

Also will need to fit it into a solenoid-operable Prontor-type (self-cocking) shutter. Were Seikosha shutters available in this configuration? Are these 5 bladed aperture shutters or were there variants with more leaves, preferably rounded leaves? Are the lens cell threads and front/rear element spacing compatible with Copal/Prontor/Compur (and if so what size)?

Thanks!

[renes]

I had Mamyia 50/6.3 lens on 6x9 camera and it covered 56x80mm roll film back wide open with no darkening on corners.