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Thread: Modifying a 5x7 Premo Long Focus Lens Board for Better Lenses

  1. #11

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    Re: Modifying a 5x7 Premo Long Focus Lens Board for Better Lenses

    Hmm. Having never seen a Premo Long Focus I went looking for images of one, found this: http://www.thepriceguide.com.au/inde...era-wood-case/

    The image doesn't make it perfectly clear whether the board is detachable, but it seems to be. If so, many modern 210/5.6 lenses are in #1 shutters. The #1 goes in a 39 mm hole and a #1 Copal's outer diameter is 73 mm.

    Putting a lens in #1 on the beast should be possible, will require a new board or boring a larger hole in the one you have. What have I missed?

  2. #12

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    Re: Modifying a 5x7 Premo Long Focus Lens Board for Better Lenses

    I'll be taking photographs of all of my cameras over the next few days to make a section for then on my website. I'll upload some pictures of the Premo Long Focus here so everyone can see it. It really is a very unique camera (the picture you link to doesn't do it justice).

    The lens board is detachable. Move a switch and it drops down and out (opposite how the board on a Speed Graphic would).

    I just picked up a Bausch and Lomb Unicum lens and shutter (I believe this was the predecessor to the Victor lens that came on many of the Premo Long Focus and Premo Senior cameras) on a lens board. This is another lens used on the Premo line so I'm banking on the board being the same side. I'll sway this lens/shutter onto the original lens board and keep that as an authentic function lens and I'll bore out the hole on the new board so that it takes larger lenses. I have an 8.5 inch Kodak Commercial Ektar in a #3 Acme Shutter that I swap between a few cameras that I'd like to see on the Premo Long Focus it fits. Its 8.5 inch/ 215.9 mm so should have no problem covering 5x7 (am I right about this?).

  3. #13

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    Re: Modifying a 5x7 Premo Long Focus Lens Board for Better Lenses

    Quote Originally Posted by Fragomeni View Post
    ...

    I just picked up a Bausch and Lomb Unicum lens and shutter (I believe this was the predecessor to the Victor lens that came on many of the Premo Long Focus and Premo Senior cameras) on a lens board.
    ....
    No, the Unicum shutter is the same construction as the Victor, made in the same time. There were more than ten different names given to these shutters, some of them having a slightly different dimensions but the same basic construction. (while I'm typing this I have a nice Unicum shutter with its lens in front of me, used as a paper weight - after I have discovered it is useless for precise shutter timings). These shutters were out of business in about 10 years after their invention due to their insufficiency in "modern" (of that time) photography. Pity, they look nice, don't they?

  4. #14

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    Re: Modifying a 5x7 Premo Long Focus Lens Board for Better Lenses

    Poco and Premo were for "photo interested amateur" but all models had detachable lensboards. There was quite a range of lens alternatives. Besides the RR, and the Goerz series III, Zeiss VIIa, there was a rear landscape achromat. In addition, two wide angle cells could be installed in the Victor. My problem with the Victor, or rather the Poco variant, is that it still works - but doesn't give either reliable or reproducable exposure times. If anyone is interested in admiring the woodwork of the Premo, there is a nude Premo Senior on e**y (Germany).

  5. #15

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    Re: Modifying a 5x7 Premo Long Focus Lens Board for Better Lenses

    Quote Originally Posted by Fragomeni View Post
    ...

    I just picked up a Bausch and Lomb Unicum lens and shutter (I believe this was the predecessor to the Victor lens that came on many of the Premo Long Focus and Premo Senior cameras) on a lens board.
    ...
    Now it is the time for a test... Do you know the special optical property of the shutter blades material in your Unicum shutter? If not yet, take a closer look at the shutter blades through the lens while shining a torch light through it from the other side (or look at the sun through the lens in the same way)... (It is called the Galli test in the modern physics texbooks...)

  6. #16
    neophyte
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    Oct 2004
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    Australia
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    Re: Modifying a 5x7 Premo Long Focus Lens Board for Better Lenses

    If your measurements are correct your borad has an opening that should just be large enough for a #1 shutter (17/16 ~ 39mm) according to Dan's dimensions. The shuttter itself will overhang: I dont know if this will be a problem---is the board recessed behind standards or flush. If you have a #1 shutter why not give it a go without modification?
    "In the field of observation chance favours the prepared mind" -- Pasteur

  7. #17

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    Re: Modifying a 5x7 Premo Long Focus Lens Board for Better Lenses

    No, the Unicum shutter is the same construction as the Victor, made in the same time. There were more than ten different names given to these shutters, some of them having a slightly different dimensions but the same basic construction. (while I'm typing this I have a nice Unicum shutter with its lens in front of me, used as a paper weight - after I have discovered it is useless for precise shutter timings). These shutters were out of business in about 10 years after their invention due to their insufficiency in "modern" (of that time) photography. Pity, they look nice, don't they?
    Thanks for the correction. I've seen both positions written (same thing vs. predecessor) but I dont think it really matters haha. Either way, you are right, they are quite nice to look at. It would be nice to have one that was also consistent and dependable with its timing.

    Poco and Premo were for "photo interested amateur" but all models had detachable lensboards. There was quite a range of lens alternatives. Besides the RR, and the Goerz series III, Zeiss VIIa, there was a rear landscape achromat. In addition, two wide angle cells could be installed in the Victor. My problem with the Victor, or rather the Poco variant, is that it still works - but doesn't give either reliable or reproducable exposure times. If anyone is interested in admiring the woodwork of the Premo, there is a nude Premo Senior on e**y (Germany).
    Where did you find the information on the lenses that were available? Can you share a link please. I'd like to pick up a few and see what I can do with it.

    Now it is the time for a test... Do you know the special optical property of the shutter blades material in your Unicum shutter? If not yet, take a closer look at the shutter blades through the lens while shining a torch light through it from the other side (or look at the sun through the lens in the same way)... (It is called the Galli test in the modern physics texbooks...)
    Haha, do you mean...paper!? At least this is what the shutter blades in the lens that came with the camera, a Gundlach Op. Co., were made of. I took it apart since it was already a loss. I tell ya, I can string down practically any camera and rebuild it with my eyes closed and both hands and one hand tied behind my back but shutters still terrify me. This one I actually managed to get working a little smoother but when I got into the aperture blades (there were completely fused/melted together and warped to death) I tried peeling them apart and re-assembling them (purely for exercise as they would have operated even if I got it) and it was a nightmare. I'd love to be able to CLA and repair a shutter and aperture blades like I can a camera but I just dont think its in the cards.

    If your measurements are correct your borad has an opening that should just be large enough for a #1 shutter (17/16 ~ 39mm) according to Dan's dimensions. The shuttter itself will overhang: I dont know if this will be a problem---is the board recessed behind standards or flush. If you have a #1 shutter why not give it a go without modification?
    Can you explain exactly what you mean by a #1 shutter. I think Im confusing myself a little. The original lens/ shutter assembly had completely non functioning aperture blades and now after my effort to dissect it, its in pieces on my bench. The new lens/shutter I have coming for it looks to be the same size. Is it this shutter (lens/ shutter assembly) you're referring to as a #1 or are you talking about getting a Packard or something?


    So now that we've been talking about the original options, what are some ideas on retrofitting the camera with a modern and sharper lens? Any ideas on a good course of action. The camera is just so cool and it has the ability to bring some useful movements into the picture so I'd love to get it set up to take some serious pictures.

  8. #18
    neophyte
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    Re: Modifying a 5x7 Premo Long Focus Lens Board for Better Lenses

    Quote Originally Posted by Fragomeni View Post
    Can you explain exactly what you mean by a #1 shutter. I think Im confusing myself a little. The original lens/ shutter assembly had completely non functioning aperture blades and now after my effort to dissect it, its in pieces on my bench. The new lens/shutter I have coming for it looks to be the same size. Is it this shutter (lens/ shutter assembly) you're referring to as a #1 or are you talking about getting a Packard or something?


    So now that we've been talking about the original options, what are some ideas on retrofitting the camera with a modern and sharper lens? Any ideas on a good course of action. The camera is just so cool and it has the ability to bring some useful movements into the picture so I'd love to get it set up to take some serious pictures.
    Standard sizes in "modern" shutters are 0,1,3 see http://www.skgrimes.com/compur/ and http://www.largeformatphotography.info/shutters.html for more. There was a 00 for miniature cameras and a #2 which is not used now. Im not quite sure when things settled on these dimensions, but in Europe maybe the 40s and pretty much everywhere by the 60s?

    Your modern lens will mostly come in such a shutter: the choices are enormous. For the size of the camera I would suggest the classic 203mm f7.7 kodak ektar. It is small lightweight and sharp and will cover 5x7 nicely ( the ektar will be in kodaks own shutter but of similar size to a copal 1).
    "In the field of observation chance favours the prepared mind" -- Pasteur

  9. #19

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    Re: Modifying a 5x7 Premo Long Focus Lens Board for Better Lenses

    Standard sizes in "modern" shutters are 0,1,3 see http://www.skgrimes.com/compur/ and http://www.largeformatphotography.info/shutters.html for more. There was a 00 for miniature cameras and a #2 which is not used now. Im not quite sure when things settled on these dimensions, but in Europe maybe the 40s and pretty much everywhere by the 60s?

    Your modern lens will mostly come in such a shutter: the choices are enormous. For the size of the camera I would suggest the classic 203mm f7.7 kodak ektar. It is small lightweight and sharp and will cover 5x7 nicely ( the ektar will be in kodaks own shutter but of similar size to a copal 1).
    Thank you. Can anyone confirm that a no. 1 shutter will work with this? I may be able to pick up a 250mm lens in a no.1 and confirmation would be nice before I spend any more money.

  10. #20

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    Re: Modifying a 5x7 Premo Long Focus Lens Board for Better Lenses

    The lens is in a Copal 1 shutter.

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