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Thread: update on RGB vs. Grayscale scanning

  1. #1

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    update on RGB vs. Grayscale scanning

    I asked a question last week regarding how best to scan PMK 4x5 negatives - as RGB or Grayscale scans. For those interested I wanted to share the results of my test. I took a sheet of tri-x developed in PMK to my local lab which uses an Agfascan XY-15 flatbed scanner for high-res scanning (8000 element flatbed, Dmax of 4.1 density range of 3.9, and up to 15,000 ppi)). No, its not a drum scanner but I've had numerous 4x5 sheets of velvia scanned on this setup and printed via a LaserLightjet printer and the results are absolutely stunning.

    I had 2 scans done, one as an 80mb RGB scan, the other as a Grayscale scan. The results were quite obvious. The shadow areas of the Grayscale file were muddy and lacking in detail, while the same areas of the RGB scan were detailed and maintained very nice contrast. Highlight areas were about equal on both. The differences in the shadow areas were not minor either - they were quite obvious. So, all the remaining scans I have to do will now be scanned as RGB files, then converted to grayscale and burned onto a CD. Converting to Grayscale has no effect on the quality of the RGB scan. The nice part of this is that I get the quality of an RGB scan, but they will only charge me for the files size of the Grayscale scan - which is 1/3 the size of the RGB scan.

    I can't comment if this holds true for negs developed in a non-staining developer as all I have are PMK negs, but I will not even consider a true Grayscale scan of anything in the future.

    Hope this helps....

  2. #2
    not an junior member Janko Belaj's Avatar
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    update on RGB vs. Grayscale scanning

    Well Dave, I have to disagree slightly with your final sentence: &quotI will not even consider a true Grayscale scan of anything in the future". What I mean is that you should not consider scanning your type of film in grayscale on that set-up, but I truly think that grayscale scanning on drum scanner should bring out very fine scan, and that is what we have been talking on last week post: drum scanner. I have got yesterday several really fine scans from our LinotypeHell (Heidelberg) Topaz flatbed scanner, film was efke 25 developed in XTol+Rodinal+water bath combination - not even close to your film, not exactly close to previous subject, but I don't think that it is good to generalize in any B&W experiences. Btw, set-up was grayscale with red as active channel.

  3. #3

    update on RGB vs. Grayscale scanning

    Can anyone tell us what the American, or non-European, version of the XY-15 is?
    "I meant what I said, not what you heard"--Jflavell

  4. #4
    not an junior member Janko Belaj's Avatar
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    update on RGB vs. Grayscale scanning

    John, I don't think that there where differences in names for different market. But that scanner was very expensive and unfortunately kind of out-off date in time when came the market. That was Agfa's and Fuji's last chance to catch Scitex, Heidelberg, Imacon, Howtek, ScanView and several others on the pro-dtp market. I have seen one of prototypes in '98. or '99. not sure right now. Fine scanner, fine software, but not that good as competition. And a bit late. Now are Agfa and Fuji both out of scanner busines, as well as ScanView. So, to get some more info, just "google" for agfa xy-15.

  5. #5
    Ted Harris's Avatar
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    update on RGB vs. Grayscale scanning

    Janko is correct and to add to his comments the current top-end Eversmart scanners from Creo outperform this beast. Not to say that it is not a superb scanner and will give years of excellent service if you can keep it going with legacy software and older computer operating systems. Moreover, you are not likely to find one on the used market in good working order for under $2000. Remember these machines were in the $50,000 range new. It is the same machine as Fuji Lanovia and very comperable to the Creo/Scitex Eversmart Pro.

    For reporduction through most normal sizes (e.g. 16x20 or 20x30 and even a bit larger) its performance rivals that of the best drum scanners. They only start to take the leasd when you go to true poster sizes. Also, in this scanner class the skill of the operater is perhaps as important or more important than the machine.

  6. #6

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    update on RGB vs. Grayscale scanning

    "BTW set up was gray scale with red as active channel"

    It probably isn't important since I certainly don't have hardware like you're describing but just as a matter of interest and education, how do you get a red channel in gray scale mode?
    Brian Ellis
    Before you criticize someone, walk a mile in their shoes. That way when you do criticize them you'll be
    a mile away and you'll have their shoes.

  7. #7
    not an junior member Janko Belaj's Avatar
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    update on RGB vs. Grayscale scanning

    Brian, excuse my limited english... someone experienced with scanning technique might explain with proper words, I'll try with my: every color scanner is working with 3 color sensitive elements, RGB. Those can be red green and blue CCD elements, or PMTs (photo multiplier tubes) used in drum scanners. Some not so expensive drum scanners have just one PMT with rotating filters in front of them. Scanning with only one channel is today possible on those scanners which software give you freedom to decide how to perform b&w scan. That's it. it is similar (not the same) like selecting red channel from rgb image. because based on "red-channel-preview" you do your black and white point, gamma and curve correction before final scan.

  8. #8

    update on RGB vs. Grayscale scanning

    Dave-

    When they did the RGB scans, how did they convert them to greyscale?

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