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Thread: DSLR Scanner: Lenses

  1. #91

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    Re: DSLR Scanner: Lenses

    Just an observation, not a criticism or anything... my biggest concern here is with stitching. As soon as you have the computer applying interpolation between two overlaid images, you're in the position of modifying the original scanned data - both deleting and recreating it, with added filtering in both linearly and possibly rotationally, depending where the software decides the overlay is and how well-designed the software algorithms are.

    While the intent is to extract the maximum detail from the scanned image, is fictional data around the joins necessarily the best way to achieve this?

    Neil

  2. #92

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    Re: DSLR Scanner: Lenses

    I've had great success over the last year and a half using my Nikon D800E to scan all my slides and negs. Since I came to large format from predominantly shooting macro, I already had a pretty decent setup, which I've added to and adjusted over time.
    My basic setup of accessories: Gitzo 3540LS tripod with levelling base, Arca Cube geared pan head on Gitzo levelling base, Novoflex Castel-L macro rail, light panel.
    For digitizing 5x4 (5x4 crop-mode, stitch in photoshop of 4 frames) I use the Novoflex horizontally, and use my Nikkor 85mm PC-E with shift to achieve excellent results with the minimum of digital interference in the stitching process. (I just use books beneath the light panel to get the height about right, and use a bubble level on both the camera back and light panel to check levelling, and move the camera along the rail horizontally and shift the lens vertically up and down from centred on the middle of the slide to achieve the four frames to stitch). The film is held in place and flat on the light panel with a very rudimentary frame made out of some pieces of Lego.
    For 35mm (a single frame) and 120 (6x7, 2 frames stitched) I use my 60mm AF-S micro, attached to the Novoflex rail set vertically to work like a copy stand.
    With this setup I can get a 5x4 "scan" of slightly over 80mpx; the only limitation here really is the colour information the camera can catch (e.g. the colour separation between yellows and greens on a slide of Velvia 50). Not quite in the same ballpark as a drum scan, but I'm fairly confident that this would give an Epson scanner a very good run for the money, with almost certainly sharper results.

  3. #93
    Peter De Smidt's Avatar
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    Re: DSLR Scanner: Lenses

    Quote Originally Posted by barnacle View Post
    Just an observation, not a criticism or anything... my biggest concern here is with stitching. As soon as you have the computer applying interpolation between two overlaid images, you're in the position of modifying the original scanned data - both deleting and recreating it, with added filtering in both linearly and possibly rotationally, depending where the software decides the overlay is and how well-designed the software algorithms are.

    While the intent is to extract the maximum detail from the scanned image, is fictional data around the joins necessarily the best way to achieve this?

    Neil
    Neil, that's certainly a concern. I use a stitching template in PTgui for scans made with multiple captures. In practice I haven't seen a problem, but I haven't done extensive testing. For a small number of exposures, it's not hard to manually align the samples in Photoshop. Change the blending mode of the top layer to "Difference." Use arrow keys to nudge into place. Change blending mode to "normal"
    “You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
    ― Alexander Den Heijer

  4. #94

    Re: DSLR Scanner: Lenses

    Neil, for capture methods such as an X Y stage and linear movement, the amount of invented (interpolated) data is probably far less than say when stitching conventional captures which are projected onto a 2D field from a spherical one like a panorama head would produce when rotated around a nodal point. Since with X/Y capture systems great pains are taken to align the image edge with the sensor edge and the stitching program is 'told' that a very long focal length lens is in use (I use 1000mm focal length), a nearly orthographic projection results from the captured images. This means that again, very little information needs guessing at in order to stitch images without visible seams.

    When I compare the results of my DSLR scanner to pano head stitches the results are night and day in terms of detail/sharpness. I'm not saying my film is resolving more, it isn't, just that the before and after results with film remain quite similar, not so with my digital captures.

    I once painstakingly captured a distant landscape with a Leica 50mm Summicron at f/8 on a D800E. Individually the captures left nothing to be desired. Once stitched and projected onto a flat field with a Sinc 256 algorithm in PTGui, the micro-contrast and stunning detail that was initially present had all but turned to relative mush. Quite disheartening indeed. So while your concerns are well founded, they have yet to rear their head in my X/Y capture system.

  5. #95

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    Re: DSLR Scanner: Lenses

    Excellent news, Daniel, and long may it continue.

    I guess I've been too long an engineer; I've seen most of the horrors that can happen once algorithms get in the act, and I tend to look at the bad effects first

    Neil

  6. #96

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    Re: DSLR Scanner: Lenses

    Rodenstock Scitex LFOV 108mm f5.6. Center and corner 100% crop. Excellent.
    Attached Thumbnails Attached Thumbnails Rodenstock-Scitex-LFOV-center.jpg   Rodenstock-Scitex-LFOV-corner.jpg  

  7. #97

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    Re: DSLR Scanner: Lenses

    I've been messing with lenses for my 35mm scanning recently. I thought I'd done pretty well with a 63mm/2.8 EL-Nikkor, which has a good macro reputation, but just for fun I tried a 75/4 El-Nikkor. Not their best, and a simple 4-element lens, but I was surprised how good it was. I'm assuming this is because it's a Tessar type, and these have a great rep for sharpness in the middle, better than fancier formulas, supposedly. And here with it for 35mm to APS format, I'm only using the very center of its field--the best part. I also know that my Leica 65/3.5 Macro lens has been blasted for being only a 4-element Tessar rather than some fancy thing, but you know what, it did a great job for scanning my 35mm, too.

    So I wonder if this concept of using just the best centerfield area of a longer lens and then not having to worry at all about how the [cropped out] edges perform has any application here.
    Thanks, but I'd rather just watch:
    Large format: http://flickr.com/michaeldarnton
    Mostly 35mm: http://flickr.com/mdarnton
    You want digital, color, etc?: http://www.flickr.com/photos/stradofear

  8. #98

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    Re: DSLR Scanner: Lenses

    Since 2004 have been using my DSLR for years to make digital files from my negatives. First project was to make digital files from a collection of 1,033 glass plates in our town's museum. Started scanning the collection with an Epson 3200? flatbed scanner, but soon realized that using a flatbed scanner very inefficient. Switched to a FX DSLR with a 60mm Micro Nikkor and a lightbox. Think it took me about 3 times to standardize everything.

    Presently I use a Nikon Multiphot so alignments of the film, lens, and digital back not a factor. For shooting 35mm and 120 film, the illumination is the Multiphot's condenser illumination or a small Aristo light box resting on the condenser or a double exposure 1/2 with the collated light of the condenser and 1/2 with the diffuse illumination of the lightbox. For 4x5 through 8x10 a 10.75"x10" graphiclite D5000 Standard Viewer lightbox (cost me an arm and a leg back when). For 11x14 I use a LED light panel: 12.5"x16" "LED COPY BOARD" model A3 from Honour Management Consulting Limited, CHINA... if I recall well under $100 and money well spent. It's evenness of illumination is close to perfect.

    Lenses that I have used range from Macro NIKKORs (Multiphot lenses), Leitz Luminar, Companion-S, to Macro lenses for 35mm, and a bunch of other optics. Over they years have settled on the following combinations. Lenses are stopped down 1 f/stop from the maximum aperture except where noted:

    35mm B&W and color: 200mm f/2.8 AF Micro Nikkor
    120mm B&W: 65mm f/4.5 Macro NIKKOR (Multiphot lens)
    4x5 film & 4x5 glass plates, 5x7 glass plates & film Whole Plate: 12cm Macro Nikkor (Multiphot lens) or 60mm f/2.8 AF Micro Nikkor at f/5.6 when using a Nikon copy stand on location.
    8x10 film and glass plates & 11x14 film: 60mm f/2.8 AF Micro Nikkor at f/5.6. For these film sizes I prefer to scan the negatives with my V750 PRO Scanner (6 merged scans in Photoshop for 11x14 negatives), but when faced with a stack of 8x10 glass plates.... well shooting them on a light box was so much more efficient.

    I personally print only up to 11x14". In comparison scans made with a Imacon scanner of 35mm film, the Imacon produced superior scans and the difference could be seen in an 11x14" print, but only barely. For film sizes of 120 and larger, you really couldn't see any differences. Reproduction of the tonalities between using the Imacon and the DSLR differ slightly, but not enough to matter for me. When going from film, to digital file, to digital negative, and finally to a Platinum/Palladium print... well you have to accept that some of the tonalities will change, BUT in my experience is not to the detriment of the final print.

    Films and glass plates are always masked on the light box or held in film holders. I once did a comparison of shooting a 5x7 glass plate on my graphiclite D5000 Standard Viewer lightbox with and without masking out the areas on the lightbox surrounding the glass plate and the difference was amazing.

    Very recently some of the circa 1890-1900 5x7 & 8x10 glass plates that I have encountered have a D-Max of 2.5 and more. For these I have planned on bracketing exposures and using Photomatrix Pro 6.0 (HDR application) to achieve a full tonal range final digital file. Have been shooting a step wedge to calibrate the results, but so far have seen a distorted recording of the evenly progressive densities in the step wedge.... need to do more work on this technique.

    Ilford Antistatic cloth always used to wipe the film or glass plates pre scanning.

    Comments most welcome....

  9. #99

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    Re: DSLR Scanner: Lenses

    My resolution tests are not too impressive, because the resolution of the camera is only 16Mp and lenses outresolve it. Shall I buy 24Mp crop camera to gain more resolution? Let's see. I took two x2 TeleConverters to watch the center closer. (TeleConverters are not the best - we have what we have).

    Result: much more resolution - enough to start thinking about 50Mp crop camera. (No such animal yet.)

    Optical magnification 1:1.5 (36x24mm to 24x16mm 16Mp Sony Nex). This is without TCs. TCs are used to see what's happening in the center of such setup.

    Lenses: Rodenstock Magnagon 75mm f5.6 and Rodenstock Scitex LFOV 108mm f5.6. 100% crops
    Attached Thumbnails Attached Thumbnails Rodenstock-Magnagon-75mm-f5.6-center-TCx4.jpg   Rodenstock-Scitex-LFOV-center-TCx4.jpg  

  10. #100
    Foamer
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    Re: DSLR Scanner: Lenses

    The only macro lens I have is a Nikon 105mm f2.8 VR (latest version.) This will not work for photoscanning 35mm, 120, and 4x5? I plan on stitching in Photoshop.


    Kent in SD
    In contento ed allegria
    Notte ed di vogliam passar!

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