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Thread: 35mm Slide Copying With 645DF Extension Tubes

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    35mm Slide Copying With 645DF Extension Tubes

    Technical query really.

    I'm about to archive a whole series of 35mm transparencies and 6x6 negatives. I am planning of making use of my Phase 645DF, P40+ & 80mm lens coupled to a copy stand.

    My question is which Extension Tube would be most applicable for this type of work. I cannot find anywhere that details focus distances, magnifications etc.

    Also would the 80mm with extension be appropriate for this job?

    Many thanks for your help!

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    Senior Member mediumcool's Avatar
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    Re: 35mm Slide Copying With 645DF Extension Tubes

    If the 80mm is a standard f2.8, then results will probably be dismal, particularly on 35mm slides/negs tightly cropped in-camera. “Standard” lenses are designed for distance shooting, with decent performance out to infinity.

    A Mamiya 80 or 120mm macro would provide better results, in the case of 120 originals which would be imaged near 1:1; 35mm originals on the other hand would require magnification (24 x 36 originals rendered on 36 x 48 or thereabouts sensor).

    You could try the old reverse-the-lens trick for 35 slidecopying, but I doubt if that would work well for the 120 originals. I would try enlarging lenses on an extension bellows.

    I have two Mamiya extension tubes, and can measure the maximum enlargement (along with the total tube extension) for you on my 80mm f4 macro; the lens goes to 1:1 with its own tube. These lenses are available on eBay, are superb and often cheap.

    Another thought is to use a smaller camera for the smaller copies; if I was doing this sort of thing, I would use my M645 for the biggies, and my K-5 with the same lens (on a $60 adapter) for the 35s. That would mean two batches of shooting, of course.
    Last edited by mediumcool; 16th June 2012 at 05:18. Reason: removed *work*, added *well*

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    Re: 35mm Slide Copying With 645DF Extension Tubes

    Thank you mediumcool!

    The lens is an 80mm LS f/2.8 so maybe this is not the right option.

    There are several manual focus 120mm and 80mm macro lenses on ebay and they look reasonable price wise. It looks like the 120mm might be most suitable as it is 1:1 with no adaptor.

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    Senior Member mediumcool's Avatar
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    Re: 35mm Slide Copying With 645DF Extension Tubes

    Quote Originally Posted by 6x6 View Post
    There are several manual focus 120mm and 80mm macro lenses on ebay and they look reasonable price wise. It looks like the 120mm might be most suitable as it is 1:1 with no adaptor.
    Good choices, but the 80s will be less expensive (and mine did come with the tube). So yes, you do need the Auto Macro Spacer with the 80 to achieve 1:1 (remembering that the field of view is 42 x 56mm at 1:1). The 80 also has a moving element or group, which is supposed to maintain quality; I don’t know if the same is true of the 120mm.

    Good luck!

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    Re: 35mm Slide Copying With 645DF Extension Tubes

    Quote Originally Posted by 6x6 View Post
    Technical query really.

    I'm about to archive a whole series of 35mm transparencies and 6x6 negatives. I am planning of making use of my Phase 645DF, P40+ & 80mm lens coupled to a copy stand.

    My question is which Extension Tube would be most applicable for this type of work. I cannot find anywhere that details focus distances, magnifications etc.

    Also would the 80mm with extension be appropriate for this job?

    Many thanks for your help!
    Magnification is (back focus distance)/(focus distance, and the reciprocal of the focal length is equal to the sum of the reciprocals of the focus distance and the back focus distance (This is the thin lens formula)

    ...so the back focus distance is the focal length times (one plus the magnification).

    ...so for 1:1 you would need approximately 240mm minus the length of the mirror box from the focal plane to the nodal point of the lens. ...but only if you are using a "simple" lens without internal focusing.

    I have recently done this algebra as I will be using a 120 macro... and for 2:1 I have ordered a long Sinar P3 (12") bellows to use in addition to the standard 6" bellows.

    For greater magnifications I can use P3 to P2 conversion bellows, and two 24" (600mm) P/P2 bellows, with my set of Zeiss Luminar macro lenses, which are optimised for magnifications up to 40:1.

    Filling the 645 frame with a 35mm transparency would be over-kill with a hi-res camera, but I have the option of using a 22Mpx multi-shot back that might be adequate... or does the PS de-graining function work better with higher-res files? If you use a "macro" lens that is "optimised" for 1:1 to infinity, it would not be likely to work well at over 1:1 - check the spec of the lenses.

    When I used a scanner on transparencies, at 4000 pixels/inch I could see the grain, and I thought that 2000/inch might blur out the grain and produce a better result?

    You will also have to think about masking, lighting, profiling...

    One option is to use a projector or enlarger (with the lens removed) for lighting and masking.

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    Re: 35mm Slide Copying With 645DF Extension Tubes

    The main problem with non-macro lenses for such enlargements is that they suffer field curvature which is critical at close distances, such that you cannot obtain sharp focus across the image. That said, your sensor crop will lend itself to improving the situation by ignoring the outer areas to a degree. Macro lenses are optimised to have a very flat plane of focus (hence they often recognised as being clinically sharp at normal distances, lacking in character).

    Mamiya lenses are pretty good though and it's certainly worth trying. I found that 35mm Velvia is between 18-24 MP resolution, so again you stay a bit further back from the subject and crop quite aggressively to stay within the central area of the lens.

    A shameless plug: I have sold much of my 645 gear and still have both a set of auto extension tubes and also a set of Mamiya 645N bellows which are about a year old and immaculate (we can still buy them brand new in HK). Drop me a line if you're interested in either
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    Re: 35mm Slide Copying With 645DF Extension Tubes

    See, I thought it was technical!. Thank god I'm a portrait photog. Thank you for your posts mediumcool, dick and wentbackward.

    I think I'm going to go with the 120mm macro lens. So thanks for the offer wentbackward. I like the idea of the money going on a new lens (if you see what I mean). I think 1:1 will be pretty good for my needs. I can get the slide in the middle of the frame and crop down from the 40mp.

    I'm going to use a copy stand with a good quality lightbox underneath. The slides will be held in a metal slide holder. Very similar to the setup in the other recent discussion on slide copying - although not quite as professional as the one photographed!

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    Re: 35mm Slide Copying With 645DF Extension Tubes

    Quote Originally Posted by 6x6 View Post
    See, I thought it was technical!.
    I'm going to use a copy stand with a good quality lightbox underneath. The slides will be held in a metal slide holder. Very similar to the setup in the other recent discussion on slide copying - although not quite as professional as the one photographed!
    ¿You are talking about Doug's Post on "Negatives witha digital back"?

    I will not have to bother with a copy stand for slide copying, as I can use the Sinar rail ¿with base plate or girder? as an optical bench.

    According to the lens spec on the Sinar website, the distance from the subject to the image plane will be from 540mm to 860mm, so, with the light source beyond that I will glad I have plenty of mono-rail!

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    Re: 35mm Slide Copying With 645DF Extension Tubes

    I have Mamiya645 Auto Bellows (Tilt-shift), I'm looking for Slide Copy Attachment and accessories.

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