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Old March 14th, 2007, 07:46 AM   #16
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So how about adapting an 35mm enlarger lens like the Rodenstock Rodagon opr an L-Nikkor. I have been thinking about this. They are in general lensen designed for reproducing flat surfaces, sharp and have screwmounts.
I have the same problem, because I don't want to make my xl2 bulkier bij using the 3 or 20x lens as relay lens, and I can't afford the p&s mini 35. (nice system with the breakout etc)
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Old March 14th, 2007, 12:34 PM   #17
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Quote:
Originally Posted by Xander van Manen View Post
So how about adapting an 35mm enlarger lens like the Rodenstock Rodagon opr an L-Nikkor. I have been thinking about this. They are in general lensen designed for reproducing flat surfaces, sharp and have screwmounts.
I have the same problem, because I don't want to make my xl2 bulkier bij using the 3 or 20x lens as relay lens, and I can't afford the p&s mini 35. (nice system with the breakout etc)
good idea.
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Old March 14th, 2007, 01:45 PM   #18
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id be concerned about the sharpness of a 35mm lens directly mounted to an hd100. if 35mm lenses are designed to resolve around 6megapixels (estimate) on a 36x24mm surface, it may have circles of confusion too large to create a sharp image on a 1280x720 1/3" sensor, not to mention its meant for a flat film plane as opposed to a prism like the hd100. anyone with experience with these mechanical lens adapters have more info?
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Old March 15th, 2007, 05:49 AM   #19
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standard 35 mm (recording) lenses are used succesfully with xl2 camorders directly via mount adapters. There is a techie in Italy that makes them. Of course you have the field of view problem. I wonder if it could be as you wrote.
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Old January 5th, 2008, 08:21 AM   #20
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finally do someone knows if P+S sells their relay lens alone ?
Would this work with the Brevis35 or the redrock M2 adapter ?

I thought about using the Zork nikon lens mount to jvc adapter with the Nikkor 20mm lens because the fujinon stock lens is used this way focusing on the ground glass.

Did someone tried ?
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Old January 5th, 2008, 11:09 AM   #21
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I can't speak for enlarger lenses, however if they have adequate aperture, why not. They would desirably have an iris aperture control. The JVC does not like to be overlit or underlit. You may get a sort of moire pattern and some small grubby marks.

I have fitted a 20mm, 28mm, 50mm and 85mm up to a HD100 via a Les Bosher adaptor so I know they work direct-to-camera. I did not subject them to a resolution test so I can't vouch for how sharp they are other than to say they looked good, which is hardly scientific.

If you just mount a SLR prime up to the HD100, via an unmodified Les Bosher or other brand adaptor, you will need the means of enabling that lens to sharply see an object that is 5" to 8" ( 125mm to 200mm ) away from camcorder focal plane or even closer, depending on the adaptor design.

That means will have to be added glass, the common method which is using an achromatic dioptre. The alternative to adding glass is to move the lens bodily closer to the groundglass and furthur away from the camcorder. Then you now need a custom adaptor for the JVC end of the thing.

The Zork mount and 20mm lens with the Brevis or M2 dioptre on front should work if that is what is happening with your existing Fujinon standard lens. You would need to make sure the centre axis of the Brevis or M2 dioptre is centred on the Nikon centre axis. If you are using threaded step up rings then this is not an issue. If you are using a mirror, or prism or hybrid mirror-prism flip path, then keeping those two axes centred and aligned is a big task. If it is off, you may see chromatic abberation.

Les Bosher or Zork for that matter could probably do a two-piece JVC mount, with a Nikon F-Mount on front and a threaded section to offset forward with grubscrews in radius holes to lock it off when the ideal focus point is found. As a custom job, it would cost you. To keep the lens orientated so the focus marks stay in the same place, the adaptor would have to be three-piece, more expensive.

The P+S Technik relay lens is designed to do all this natively. I don't know if there is another correcting element between the relay and the groundglass on the MINI35.

On the PRO35 there apparently is. This however may be intended to allow the 1/2" and 2/3" CCD cams via an eixsting relay to fully frame the image area without vignetting on the groundglass rim.

There might be an entirely new relay lens design for the PRO35. Only P+S can answer that should they choose to but it would make lots of sense to use the same relay lens across all the models if possible.

A long way back in posts past, there was reference to the P+S relay being available as a separate part. There is little reason why they would not sell it. Any business is better than no business. The nearest P+S Technik vendor to Bohol may be Singapore :

teoheric@singnet.com.sg

Alternatively, I guess you could enquire with the Sales Manager direct at P+S in Germany via email.


The same post referenced the source of the P+S relay lens as Schneider-Kreuznach, so there may even be an identical lens in an entirely different barrel capable of doing the same job.

Then it comes back to the custom mount to JVC and to back of adaptor.if the available aperture is too tight.

Last edited by Bob Hart; January 5th, 2008 at 11:49 AM. Reason: errors
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Old January 7th, 2008, 04:36 AM   #22
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correction to above post

Delete the last seven words of the last sentence. My undiscovered error.
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Old January 7th, 2008, 05:14 AM   #23
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It might be of interest that Since the 1930's when my grandfather started our family run photo business they use to invert the large view cameras they had , including some burke and james cameras, and turn them into enlargers to print the photos. So thinking about what they did i thought, yeah, the rodenstock in reverse could take a small image from a big source and it could be 'in theory' be a good relay. Hmmm. we have lots of those lyin around. including the nikkor EL 50mm f4. Time to clean the drawing board.

Last edited by Ted Ramasola; January 7th, 2008 at 05:16 AM. Reason: add text
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Old January 7th, 2008, 10:22 AM   #24
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The practice of using movie cameras a projectors was also around at that time. Using the originating camera for printing would be as close a guarantee as you could get to the print being faithful to the original subject.

At risk of making assumptions, my guess is that part of your childhood was enjoyably spent learning the visual arts. For me as a kid, photography, cinematography and movie projection held a simple magical fascination.

Electronic imaging versus smelly chemicals in a claustrophobic dark room does have its advantages.

If you ever saw Giuseppe(??) Tornatore's movie "Cinema Paradiso", the kid in the projector booth could have been me, except I was never allowed to operate the projectors. The cinema closed during the two years my family moved to another town and TV had taken over by then.

I may still have the bits of broken film hidden away somewhere if I bother to look.
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Old January 7th, 2008, 10:39 AM   #25
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Hi Bob,

Your assumptions are correct.

Now i was thinking about how you focus enlargers. Lets say that the negative is the ccd of the camera, if this is a correct analogy, so what shall be our computation for the flange distance? Ok, lets say a nikon EL 50mm is placed infront of the jvc instead of the stock.

Oh boy, now i'll be dreaming of this and wont be at ease till i actually go to our store room and dig out old stuffs! -now I wont get to do my job. Hahaha!
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Old January 8th, 2008, 09:24 PM   #26
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Ted

My really bad guess is that whatever the flange face to focal plane is on the enlarger lens, the setting or spacings for a 3x print, may go pretty close with the groundglass about 120mm away from the front element of the enlarger lens.

The JVC standard Fujinon "in air" flange to focal is approximately 37mm at a rough guess I arrived at by groundglassing the JVC standard lens focal plane and measuring the clearance crudely with a school ruler. The actual specification sheet should be findable on the web somewhere.

So my boiled down guess would be from the surface of the enlarger lens rear element ( I don't know what the flange to focal plane distance is for the enlarger lens ) to JVC flange would be about ( 48mm minus the 37mm which should be about ) 11mm.

If the enlarger lens does not have a focus trim available on it and focus relies entirely on racking the enlarger lens and its support itself, you would need to build in some sort of trim adjustment.

Which would be easiest, adjustment between the JVC and the relay lens, adjustment between the groundglass and relay lens or even both? As you intend to use dual format, you may need to have both adjustable in order to reframe the larger groundglass image of the medium format lenses. The JVC flange to groundglass distance might remain constant or vary much less than the movement of the relay lens itself for the format change. I'm not knowing enough on optical theory to be sure about this.

That is going to mean sliding tubes for light shields or concertina bellows. Support is going to be easiest to engineer if you use rods so you might as well go for the standard 60mm between centres used for bridgeplates, matteboxes and follow focus units.

Chances are that sort of hardware is already in your shop somewhere.

An interesting exercise. Whatever you come up with for dual format is going to look unique, that is for sure.

Last edited by Bob Hart; January 8th, 2008 at 09:29 PM. Reason: error
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