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Thread: BellowsN infinity focus LF lenses?

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    BellowsN infinity focus LF lenses?

    Has anyone adapted LF lenses to M645 bayonet to use on the auto bellows?

    I just got my hands on the awesome older Bellows N and I'd like to try to economically adapt a LF lens to obtain infinity (or as close to it as possible) focus. Something kind of like the old kodak ektar 127mm as they're inexpensive. I just need to figure out how to adapt it.

    Any recommendations on adapters and lens pairings?

    For me, I'd like to do more portraiture in the normal to shorter tele range. The owner whom I've borrowed the bellows from is interested in adapting something wider for landscape work with movements.

    Ideally, I'd like something that hits infinity with the bellows extended a good bit so the proximity of the standards don't interfere with the movements.

    any help would be greatly appreciated!

    Garrett

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    Re: BellowsN infinity focus LF lenses?

    Please send your friend to me offline, or have him post a question on the forum so I can save him some time. You cannot use wide angle view camera lenses on a DF using such bellows (assuming you want to be able to focus at infinity) - the math/physics of optics don't allow it; the lens would have to be mounted so close to the sensor that it would be INSIDE the DF body itself. This is why tech cameras are so popular - no space taken up by the mirror/shutter.

    As for mounting longer lenses... If they are symmetrically designed lenses you should be able to simply reverse them and mount them with the thread to the reverse ring adapter that Mamiya sold for this bellows system. Or, push comes to shove, you can use gaffe tape and cardboard; as long as it's light tight, reasonably sturdy, and close to parallel - it will work.

    For it to focus at infinity the optical center of the lens needs to be the same distance from the sensor as it's stated focal length. So an Ektar 127mm has to be seated 127mm (5 inches) from the sensor. This assumes the Ektar was a near-symetrical lens and not a telephoto or retrofocal design (I do not know the Ektar, so could not say).

    I did this with enlarging lenses for a macro project:
    Doug Peterson, Wedding Photography

    Doug Peterson , Digital Transitions | Email
    Dealer for: Phase One, Mamiya Leaf, Arca-Swiss, Cambo, Eizo, Profoto
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    Re: BellowsN infinity focus LF lenses?

    Thanks for the reply Doug! Good info.

    I was thinking of the ektar 127 because of the results shown here instead of buying and guess, I really dig his results. I didn't notice until after I made this thread where he explains that he simply cut out the lens hole from a spare cap to make the mount

    Back in the tilt, shift & swing of things | Japanorama.co.uk

    I'll try to get Mike in touch with ya, I doubt he's really looking for wide but more so infinity. Me personally, I just want to achieve a longer focusing distance so as to shoot more than just macro (headshots/etc).

    There's no real serious reason for us wanting to do this really other than an exercise of curiosity

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    Re: BellowsN infinity focus LF lenses?

    So here's what I was able to do with a Graphex 135mm f4.7 lens quickly....I did a poor job of making the mount by using a heated bottle cap to melt through the body cap and it went crooked so the lens isn't quite squared up, joys of 3am drinking

    I also got ahold of a Graphex 203mm f7.5 which works amazingly well, I'll try to get some tests done with it as well....

    The whole movements thing is quite a fun challenge that's new to me, loving it and can't wait to get a 4x5! Doing this through a 645DF viewfinder is quite a PTIA....

    Rearward tilt of the front standard to selectively focus on the face


    Maximum focal reach, lens is quite soft even stopped down 2 stops...


    maximum close focusing distance


    forward tilt to bring both the camera and face loosely into the same plane of focus...The camera is over a foot forward of the face. Notice the out of focus areas everywhere else


    Mamiya 645DF body on a AutoBellows N with a Graphex 135mm f4.7
    Last edited by dizzyg44; 28th October 2012 at 08:21. Reason: typos

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    Re: BellowsN infinity focus LF lenses?

    Nice work!

    Is the front standard/lens holder of the M645 bellows removable, or is it all one piece with the M645 bayonet? If it were removable like on a view camera, then you could cut large format lens boards down to the right size. If not, then drilling a body cap according to the shutter size would seem the best option. The body cap becomes the lens board. Bayonet-mount LF lenses - now that's handy!

    Ray

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    Re: BellowsN infinity focus LF lenses?

    The bayonet is screwed directly to the standard, so not field removable.

    I simply used a body cap to make the lens board I need to make another one as I was too sloppy with the current one as I made it around 3am after a few drinks lol

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