Macro set up for digitizing film...

Discussion in 'Macro' started by michael_matsil, Dec 11, 2019.

  1. Theoretically you should need right around 25mm of extension tube to get you to 1:1. However, what you have right now might be a good compromise. It sounds like you've already used up the adjustment range of the ES-2, and adding more extension tube will only make that condition worse. 40mp is vastly more resolution than your film, so you can afford to use less than the entire sensor. You might even try slightly less overall extension if you have trouble obtaining perfect focus. Be sure to face the emulsion side of the film towards the camera, and then correct in post. Good luck! Can't wait to see your results.
     
  2. Wayne - Your 105mm macro lens should work. I have been scanning 35mm slides using the set-up below. It consists of an old Kalt slide duplicator attached to my Canon 100mm f:2.8 macro lens mounted on my Canon 5 DIV (I previously used the 5D II shown in the photo). To attach the slide duplicator, I first removed the internal lens in the duplicator, attached a 15mm length, 42mm diameter, extension tube (same as T-mount thread), plus a 42mm to 58mm lens adapter. I also installed a black paper 1/ 1/4" I.D. light baffle in the duplicator, where it necks down before joining the extension tube. The total length of the duplicator plus extension was 6.25", which I determined before-hand to be the approximate correct distance from the lens for a slide to almost completely fill the camera sensor area. Since I already owned the macro lens, the total cost was about $25 or $30, with all parts purchased on eBay. My source of illumination is a white matt board illuminated by flash. I find that auto-focus works as well as careful manual focus for all but very warped slides. DSLR scanner.jpg
     
    DavidTriplett and Wayne Melia like this.
  3. Thanks Glenn
     
  4. The closer you get to 1:1 magnification, the less effective is auto focus (or any lens focusing method). At exactly 1:1, neither method works. There are no degrees of freedom left in the L1+L2 = FL equation. Magnification is determined by the lens, and the only focusing option is to adjust the lens to film holder distance.

    This formula is confused when a lens alters the focal length when focusing, in order to reduce the length of travel and extension of the lens. Most AF lenses work in this fashion. A Nikon 105/2.8 AF-D lens, for example, has a focal length of about 105 mm focused at infinity, but only 86 mm at 1:1.

    In theory, if you use a 50 mm lens, the film holder must be 4x50 from the film plane. That's 200 mm, or nearly 8". A 105 mm lens would require 420 mm, or over 16". That's pretty cumbersome unless you have a fixed setup.

    There is nothing magical about 1:1 magnification, and a little less (perhaps a little more) works too. If you have a DX (or smaller) sensor, capturing the entire film image will require significantly less than 1:1 magnification. Mounted slides mask a significant portion of the film frame, so less magnification is still effective.

    Using a FF camera, the most practical procedure is to set the lens to slightly less than 1:1, using the focusing ring. Execute a rough focus by adjusting the lens to slide distance, usually with a sliding tube arrangement. Finish by fine-tuning the focus using the focusing ring (or AF).

    Nikon K rings are intended for use with an inverted lens, attaching a 52 mm filter ring to the camera flange. They are long discontinued, and often hard to find. It's not necessary (or helpful) to invert a lens unless you want magnification greater than 1:1. At 1:1, it's a wash. A Nikon PX-13 extension tube (27 mm) fits behind the lens, flange to flange, and gives exactly 1:1 magnification with a 55 mm Nikon macro lens at it's closest focusing distance.
     
    DavidTriplett likes this.
  5. More specifically, the 55/2.8 without extension goes from infinity to 1:2, and with 27.5mm extension from 1:2 to 1:1.

    The lens has numbers on it with that assumption in mind. If you don't need the numbers, then other
    extensions will work. A shorter extension won't get you to 1:1, and longer one won't go down
    to 1:2, so you will have a gap in magnification coverage.

    Some years ago, I got a shorter Nikon extension tube, which was just right for use with my D70s.

    I now have a real PK13.
     
  6. Out of the box, the 55/2.8 will focus from infinity to 1:2. A longer extension (any extension) will no longer allow you to focus at infinity, but at the closest, greater than 1:1. The focusing helix has an extended range of travel, the differential (from 27 mm) would have to exceed that range before 1:2 would not be possible. Some extension is necessary to reach 1:1.5 for a DX camera, However the PX13 would work in that instance.
     
  7. Yes. The 27.5mm maximizes the contiguous magnification range.

    When I wanted to use the 55/2.8 with my D70s, I found a Nikon E2 extender, which is somewhat less than 27.5mm,
    but about right for DX. That was $9 with shipping, where at the time PK13 was much more.

    I ended up getting a PK13 along with a bunch of other stuff in a box from Goodwill.
    Also including the Nikon F hot shoe adapter, and a focus screen, I believe for the F.

    The E2 is pretty close to exactly right for DX cameras, though.
    It seems to be 14mm, and is semi-automatic. You press a button on
    it to open the aperture. That is, the opposite of DOF preview.

    Nikon Extension Tube E2

    More of the fun things that Nikon makes for us to use.
     
  8. Much depends on how much film you are going to digitize.

    If it is more than a few hundred images, you owe yourself to at least check out the actual film digitizers -- a few are still available.

    If you must use a camera, then invest in a controlled light source, a high quality copy lens, and a good copy stand.

    slide-copying-pg.jpg

    The Nikon tube copiers are better than most, but there are reasons they are common in "like new" condition on eBay.
     
  9. As was my ES-1. I suspect that they generally get only limited use, as most people (me included) have a finite number of slides (or negatives) to digitize, and once that project is complete the equipment is no longer needed. This, as opposed to a production-grade setup that sees long-term, ongoing use, for which I would not recommend an ES setup.
     
  10. _____________
    My setup is built so that a slide is placed at approximately 160mm from the front element of my 100mm macro lens. This provides a measured magnification of approximately 0.86 and the image area of a slide is recorded on approximately 22 megapixels of the 30 megapixels total for my Canon 5D IV. Although I lose some resolution, this magnification permits accurate auto-focus, a trade-off that I am willing to accept.
     
    Last edited: Jan 8, 2020
    Ed_Ingold likes this.
  11. I copied a lot of slides, mostly Kodachrome, well before digital. I had a Honeywell Repronar and did color and exposure correction, cropping, etc.

    For a while, I tried using color film and then digitizing it.

    Like nearly everybody else, except for an elite group of film nuts, however, I made the transition to digital cameras in 2004.
    But I had 10s of thousands of images on film, I quickly discovered how much better a real film scanner was than the rather large accumulation of slide copying equipment I amassed.
    In stories told elsewhere on this site I detail my work with a Canoscan 4000, and later with a Nikon Coolscan 9000. You can, if you wish, start on these at places like
    LINK:2015: A scanning Odyssey - Nikon Super Coolscan LS-9000 ED --(scroll past alphabet soup from earlier pasting abilities now lost)
    LINK:Nikon Coolscan LS9000 ED, ICE, and CanoScan F4000US - Part 2

    But Like Cassandra (Link: Cassandra - Wikipedia), I am doomed to tell my story over and over again....
     
  12. A lot has changed since 2004. Digital cameras have 3x the resolution of color film and a dynamic range sufficient to capture all of the nuances. Exposure is not fixed, as in conventional film scanners, so Dmax is not limiting.
     
  13. ______________
    Canon states that the working distance for it's 100mm internal-focusing macro lens is 5.9 in. = 150mm at 1:1 magnification. Whereas from thin lens theory, 1/L1 + 1/L2 = 1/fl, the working distance, L2, at 1:1 magnification, would be 200mm, and the distance from the sensor to the slide would be 400mm, consistent with Ed's calculation for a 105mm lens. From Ed's first paragraph, the actual working distance is considerably less, due to the decrease in focal length at 1:1 magnification that he refers to in his second paragraph, and the fact that the lens is not a thin lens, so the front nodal point should lie somewhere well behind the front element, although I have found no information on it's actual position. In any case, using a 100mm or 105mm macro lens is not as cumbersome as thin lens theory would imply. However, I would still recommended a fixed setup, if only to control vibrations.
     
  14. The real limitation is that of the film, not the scanning. 4000 ppi (as it was in 2004 and still today) resolves grain and dye clouds, beyond that lies mostly self delusion with a few very special and rare kinds of images as an exception.
     
  15. And also, a LOT of effort is put into really flat fields of focus and rectilinear imaging on high quality film scanners, which, after all, are made for just one purpose.

    Top quality macro lenses may or may not be quite as good for this specialized use of film scanning.
     
    Last edited: Feb 10, 2020
  16. Duly noted. I would suggest, a slight tweak of barrel/pin cushion distortion in post. Capturing into the unexposed area of the film will avoid any unwanted cropping of the image area. Also, the Makro-Planar 50mm f/2 design has a very flat field.
     

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