Leigh did you get it now or not, that this g...damn shutter was build first for the Norma?? did you get it?????
I know my english is'nt perfect but I like to state things which are as they are!!!!
Just to give you an idea about the photographer dynasty of the Koch's the idea behind the Norma, was to build a camera which everything is exchange able and the old fits to the new etc.
Cheers Armin
I'd like to go back to the original question, please! I have been trying to work with a fisheye lens on my Sinar F and/or Norma. The lens is the revived corpse of a 37mm f/4.5 Mamiya RB fisheye which had been dropped so hard (not by me) that the body was actually bent - but the glass unharmed. Amazing! It produces a complete image circle which just fits inside 5x4 when using a paper neg and the Fidelity's darkslide as a shutter, but for film that's not quick enough. The built-in Mamiya shutter is no more, and I can just about use the Sinar behind-lens shutter. But all is very tight, as the lens needs to be very close to the film; I get a bit of vignetting from the Sinar shutter, and getting a bellows in as well is very tricky. So when space is tight, a slim FP shutter built into the rear standard would be wonderful. I have thought about using a Speed Graphic or other field-camera-form device, but there can't be any part of the camera forward of the front of the lens, as it would be in the picture; and the Speed Graphic's lensboard is far too small anyway. Any creative ideas welcome!
Would it be possible to fabricate a slightly recessed lensboard to place the lens just-so, near enough to the shutter to not vignette?
John, why don't you put the lens' cells in a newer shutter? I note that their native shutter's highest speed is 1/400th, so it may be a #1. If not a #1, a #0.
Take the cells out and ask them what they fit. Simple test that doesn't require measuring: if their threads are the same diameter, #0. If the front cell is larger, #1.
Doing this and, if necessary, mounting it a recessed board, will probably be less fiddly than kludging it in front of a Sinar shutter ...
Dan - unfortunately they aren't cells as in a normal LF lens. What we have here is an integral lens for a Mamiya RB67 MF camera, whose now-departed shutter was operated from the camera body with linkages. There are two main groups in the lens body, but they are mounted by their rims to what are essentially large female screw threads at each end of a fat tube.Originally Posted by Dan Fromm
David - yes, but I fear that's where we already are; it's within a few mm of the shutter blades.
John, I've never tried to take an RB lens apart.
I have, though, taken a Koni-Omega lens apart. It, like yours, lived in a shutter that was operated from the camera body with linkages (shutter cock and shutter trip, and there was a rangefinder coupling). It was in a #0 with all those funny linkages. Its cells went right into a normal cock-and-shoot #0.
Your lens' cells have to attach to their shutter somehow ...
Did the RB fisheye require that you raise the mirror before installing the lens? I wouldn't have thought so--the 35mm fisheye for the Pentax 6x7 does not, and neither does the 30mm Arsat which mounts on the range of 6x6 SLR cameras with Pentacon Six mounts. Thus, the rear of the lens should not need to be closer than 60mm or so to the film, else it would interfere with the reflect mirror.
That should be more than enough to use on a Sinar with a Sinar shutter. I would recommend finding the Wide Angle Bellows 2, which is a very soft, double-pleat bellows that allows me to use a 47mm Super Angulon (not much retrofocus in that design) on a flat board and still have room for 6 or 7 degrees of tilt. The shutter will add thickness, but the retrofocus nature of the fisheye should provide room for that.
The (required) rear filter of the 30mm Arsat is only 31mm, as I recall. If positioned close to the Sinar shutter, there should be no problem of vignetting--that shutter is about 75mm in diameter. I have not used a Pentax fisheye but I've handled one, and it seemed similar.
Something's not adding up for me with your situation. The only explanation I can come up with is that the rear of the lens isn't as close to the shutter leaves as you think they are--unless the lens mounts on the camera with the mirror locked up as with some of those old Nikon fisheyes.
I have been toying with the idea of creating a Sinar board with a Pentacon Six mount of some sort. If I machined it to the right thickness and machined the bayonet pattern in it, I think I could make a twist mount that would work. That would put the rear of the lens quite close to the shutter. I've experimented with the physical placement of a 180mm CZJ Sonnar in that mount, but I ought to pull out the 30mm fisheye and play with that to see what might be possible.
Fisheye lenses should provide a round image about three times the focal length of the lens. The 30mm Arsat should make a 90mm circular image, and the 37mm Mamiya should make a 110mm circle. I would have thought it just a bit big for a 4x5 sheet if you want the full circular fisheye image. To use it as a full-frame fisheye, we'd need about a 50mm fisheye, which would be wondrous indeed.
Rick "noting those Arsat fisheyes are excellent and inexpensive" Denney
I never used the RB fisheye on an RB, as it came to me in a box of studio scrap (!) with some other stuff I needed (well, wanted anyway). But I have no reason to suppose it required mirror lockup, it fits in a standard RB bayonet in the normal way. So I dismantled an old RB extension tube (from the same box) and fixed half of that to a Sinar panel. The rear of the lens is near enough flush with the rear surface of the panel. The amazing bent body had to be taken apart, partly by unscrewing but partly by machining metal away. That was needed to release threads hopelessly jammed, and also to remove the "ears" on the front which get in the way when you use it for the whole image circle. The two cells are held in the said tube by screwing in either end, and the shatter was mounted between, not connected directly to the cells. The shutter has now gone, and in the space is a plate with 3 jacking screws, which allowed me to realign the optics despite the fact that they live in a tube which is still a little bent, despite some straightening. All rather drastic, but it was otherwise a lost cause. Shame, the serial number is 10005 so it's probably a really early one.
The image circle is about 95mm, so it fits snugly on 5x4. (I.e. a little less than 3xf)
Perhaps I wasn't as clear as I should have been; I can, with care and a home-made short bellows, squeeze in the lens and the Sinar shutter, and focus it; the shadow of the rear edge of the shutter marginally doesn't encroach on the image circle. By the way, this is best done on a Sinar F, as it has much less clutter of engineering in front of the plane of the lensboard than a Norma.
So my query was prompted by a desire to have a bit more freedom with this lens, which a slim FP shutter built into the rear standard could provide; but also I have started to experiment with other fisheye solutions. For example, Sidney Ray points out in his book on photographic optics that a plano-convex lens can form an uncorrected but functional fisheye lens if mounted with the plane side facing the subject, and a small stop flush with the plane surface. Even the aspheric plano-convex lens from the lamphouse of a 35mm projector turns out to provide a surprisingly good image when used this way - but requires a space between the rear of the lens and the film plane of only about 30mm. Crucially this means that the body of the Sinar shutter is too thick to allow the standards to be close enough together to focus. I have made a 1-pleat bellows and taken pictures this way at about f/11 on (slow) paper using a lenscap as shutter, but using film is impractical. The pictures are sharp in the middle, softening towards the edges of course, with angular coverage only moderately less than the Mamiya, and an image circle of similar size.
All this developed, by the way, from earlier experiments using a 16mm Zenitar intended as a full-frame fisheye on 35mm, mounted on a modified Kiev-60 and fitting a complete image circle on 120 film. That has been a very successful enterprise despite the lack of any viewfinder, and has resulted in several saleable images. The modification of a defunct Kiev-60 was again rather radical, I needed to do away with the mirror box (hacksaw!) and fit a new lens panel with exact Nikon register to match the lens. And modify the linkage between shutter button and shutter. One of the hoped-for benefits of doing the same thing at 5x4 is the ability to see the picture before taking it, another is the usual - to have a larger negative, more resolution, and potentially bigger prints.
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