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Thread: Best approach for repro work where size reduction is required?

  1. #1

    Best approach for repro work where size reduction is required?

    I have a digital artwork that's 7 x 4 inches and I plan on printing it on transparent film at that size. I'm trying to reduce it in size to 3.5 x 2 inches so it fits on a business card. It will be embossed, so I need a film negative to make the plate.

    I plan to use my homemade 4 x 5 camera as a process camera to create a negative where the work is the desired 3.5 x 2 inches.

    The reason I'm not just printing the digital transparency smaller to begin with is that my inkjet isn't capable of producing the kind of detail that the artwork demands.

    I was under the impression that my lens (G-Claron) is best suited for 1:1 transfer. Will I lose any detail or encounter any issues reducing the size? Is there a more preferable way to accomplish this?

    Any advice/comments would be much appreciated.

  2. #2

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    Re: Best approach for repro work where size reduction is required?

    Your G-Claron will do just fine at 1:2. Heck, it'll do fine at infinity as well. You're just making a 50% magnification close-up; not all that demanding. Just make sure you get everything parallel (gridded ground glass helps) and that all four corners and the middle are really in focus before you stop down. Don't forget to compensate for bellows extension.

    Best,

    Doremus

  3. #3

    Re: Best approach for repro work where size reduction is required?

    Are you referring to making the image larger? I'm trying to make the image half its original size. Maybe I'm confused.

  4. #4

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    Re: Best approach for repro work where size reduction is required?

    I'm also referring to making the image half it's original size on the negative. It is just close-up photography. A ratio of 1:2 denotes half life-size (1 unit on the film equals 2 units of the original).

    So, mark your ground glass with the size you want your final negative to be. Then set up your camera so that your original just fills the marked area. This is going to be the most time-consuming part. It really helps if you have a monorail camera and can move both standards. Anyway, spend your time here getting exactly the right-size image and getting it square and parallel.

    Once you have the shot set up. you'll need to adjust your exposure from your meter reading because your bellows will be extended quite a bit. The normal adjustment factor for 1:2 is 2; that means you need to multiply your shutter speed by 2 (e.g., 1/30 x 2 = 1 1/5) or adjust your aperture accordingly, since this is a one-stop adjustment, you would open your aperture one stop.

    Alternately, if you have a darkroom, you can use an enlarger to project a half-size image of your negative onto a piece of film. You'll have to test to get your exposure right, which, if you haven't worked it out already, can take a bit of time and film and, of course, must be done in complete darkness. It has the advantage of being able to work with the image a bit easier than with macro photography, but may be more trouble than you need for just one shot.

    Hope this helps,

    Doremus

  5. #5

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    Re: Best approach for repro work where size reduction is required?

    “that means you need to multiply your shutter speed by 2 (e.g., 1/30 x 2 = 1 1/5)”

    No, 1/15 not your answer.

    I always looked at it as dividing the original shutter speed.

  6. #6

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    Re: Best approach for repro work where size reduction is required?

    Quote Originally Posted by Bob Salomon View Post
    “that means you need to multiply your shutter speed by 2 (e.g., 1/30 x 2 = 1 1/5)”

    No, 1/15 not your answer.

    I always looked at it as dividing the original shutter speed.
    You're absolutely right, multiplying a speed gives a higher speed, the opposite of what is necessary in this case.

  7. #7

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    Re: Best approach for repro work where size reduction is required?

    Quote Originally Posted by kendolinator324058943 View Post
    to reduce it in size to 3.5 x 2 inches so it fits on a business card.
    An optimal lens for this job is Linos Rodagon D 2x reversed, search ebay Rodagon D 2x, there are a lot used from Machine Vision systems, it may cost $200 used or less, see sold items

    Click image for larger version. 

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    Today Rodagons are sold for industrial inspection cameras of linear sensor type, a similar application is Hasselblad X1 / X5 scanners also sporting a rody inside.

    Other enlarger and taking lenses would also perform ok, better is reversed. But the Rodagon R and D are optimized for that magnification range, performing optimally and way beyond a human eye may see.

  8. #8

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    Re: Best approach for repro work where size reduction is required?

    Quote Originally Posted by Pere Casals View Post
    An optimal lens for this job is Linos Rodagon D 2x reversed, search ebay Rodagon D 2x, there are a lot used from Machine Vision systems, it may cost $200 used or less, see sold items

    Click image for larger version. 

Name:	s-l1600.jpg 
Views:	4 
Size:	15.9 KB 
ID:	187365

    Today Rodagons are sold for industrial inspection cameras of linear sensor type, a similar application is Hasselblad X1 / X5 scanners also sporting a rody inside.

    Other enlarger and taking lenses would also perform ok, better is reversed. But the Rodagon R and D are optimized for that magnification range, performing optimally and way beyond a human eye may see.
    You would not reverse the D for this application. You would just need the proper D. There are 2 different 75mm ones and a 120mm.

  9. #9

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    Re: Best approach for repro work where size reduction is required?

    Bob, those easily found used are the x1 and x2, the x2 reversed is just optimal for x0.5, which is exactly the requested magnification...

  10. #10

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    Re: Best approach for repro work where size reduction is required?

    Quote Originally Posted by Pere Casals View Post
    Bob, those easily found used are the x1 and x2, the x2 reversed is just optimal for x0.5, which is exactly the requested magnification...
    You don’t reverse it.

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