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  1. #11
    Mark Antony's Avatar
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    Quote Originally Posted by snaggs View Post
    I just read this review;

    http://www.boeringa.demon.nl/menu_technic_ektar100.htm

    It seems that Ektar 100 is no finer in grain than Velvia 100?

    Daniel.
    Read his footnote:
    Now a scanner doesn't need to do a lot to faithfully reproduce a slide, besides capturing the pixels. However, with color negative film, the limited contrast range of the original negative needs to be expanded to a full contrast range from the deepest black to pure white. It is the equivalent of stretching an elastic band 10x. Now each tiny error in determining the exact value of the Red/Green/Blue (RGB) values of the pixels of a color negative gets expanded / exaggerated as well in the process. Hence, almost inevitably, a high resolution scan result of color negative will look a bit more "grainy" as well, as these pixel errors have been enhanced as well. I think this is the main reason why the Velvia 100 results looks more smooth, compared to Ektar 100.

  2. #12

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    The review told me a lot more about the problems of scanning than about the films, although some interesting information about the films was given. Since most of us scan film for printing, the insights were quite valuable. The remarks about the low contrast of color negatives making for more difficult scanning were interesting. They make some sense, and maybe the hybrid site should explore this issue more fully. My own experience has been that transparencies have been somewhat harder to scan than negatives. The review reveals what I have found to be a very common (increasingly common) misunderstanding about color negative films. People think the orange-brown color they see is a filter, where it is really part of a mask. The two are quite different.

  3. #13
    Photo Engineer's Avatar
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    Quote Originally Posted by Mark Antony View Post
    Read his footnote:
    Now a scanner doesn't need to do a lot to faithfully reproduce a slide, besides capturing the pixels. However, with color negative film, the limited contrast range of the original negative needs to be expanded to a full contrast range from the deepest black to pure white. It is the equivalent of stretching an elastic band 10x. Now each tiny error in determining the exact value of the Red/Green/Blue (RGB) values of the pixels of a color negative gets expanded / exaggerated as well in the process. Hence, almost inevitably, a high resolution scan result of color negative will look a bit more "grainy" as well, as these pixel errors have been enhanced as well. I think this is the main reason why the Velvia 100 results looks more smooth, compared to Ektar 100.
    He has it backwards. First, the negative scale is being compressed in a linear fashion. Second, the Velvia is smooth due to the much lower contrast and the lossy nature of the toe and shoulder when reproduced pos-pos. The negative film is linear.

    PE

  4. #14

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    Quote Originally Posted by Mark Antony View Post
    Read his footnote:
    Now a scanner doesn't need to do a lot to faithfully reproduce a slide, besides capturing the pixels. However, with color negative film, the limited contrast range of the original negative needs to be expanded to a full contrast range from the deepest black to pure white. It is the equivalent of stretching an elastic band 10x.

    This is ridiculous. Full range color tranny film typically has a density range of around 3.0 - 3.4. It's hard to measure anything higher than 3.4 due to the lack of test targets above 3.4. But the lack of test targets tells you that there's not a lot of need.

    A full range color negative film typically has a density range of around 2.5 to 3.0.

    This is hardly a 10x difference. Makes me wonder what he's smokin'.

    Quote Originally Posted by Mark Antony View Post
    Now each tiny error in determining the exact value of the Red/Green/Blue (RGB) values of the pixels of a color negative gets expanded / exaggerated as well in the process.
    This is just silly. I've seen several scans where you could measure hues in the shadows and highlights and see that the hues are stable as value and saturation change. No worse than darkroom paper, and arguably better.

    If scanning negative film really didn't work, no one would be doing it.

    Quote Originally Posted by Mark Antony View Post
    Hence, almost inevitably, a high resolution scan result of color negative will look a bit more "grainy" as well, as these pixel errors have been enhanced as well. I think this is the main reason
    Quote Originally Posted by Mark Antony View Post
    why the Velvia 100 results looks more smooth, compared to Ektar 100.[/I]
    Um, no. Color negative might look a bit more grainy then color tranny, but that's not why. The reason why is that graininess is directly related to density. And density in trannies is in the shadows where the resulting graininess in the print is hard to see. With negatives the density is in the highlights, and the resulting graininess in the print is therefore much easier to see. This is just simple physics.

    Any tranny film will "look smoother" than a comparable negative film if the only thing different is that one's a tranny and the other is a negative. This is so obvious that mostly we don't even bother to comment on it.
    Bruce Watson
    AchromaticArts.com

  5. #15
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    I wish I could give the both of you a course in color system design (neg-pos and pos-pos). It would explain a lot to you that you are both missing along with the review, on color photo systems.

    Just consider one major flaw in your overall thoughts. A color negative system is being COMPRESSED to yield a tonal range of from 0.1 to 3.0 in a final comparable positive image or as high as 4.0 in motion picture print films. Common densities can be read up to 6.0 and I have done it! A value of 4.0 is not uncommon in a neg-pos print.

    All film systems have the highest grain in the region of viewed dmax of the final positive image. In pos-pos, the dmax is the fastest and coarsest grain. In neg-pos, dmin is fastest and coarsest which, when printed, becomes dmax.

    PE

  6. #16
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    Quote Originally Posted by Photo Engineer View Post
    I wish I could give the both of you a course in color system design (neg-pos and pos-pos)
    Hello Ron:

    How about we do a radio program on this topic ?? You game ??

    Thanks

    Scott

    PS: See you in Rochester NEXT WEEK.. I am REALLY looking forward to it !!
    Scott Sheppard
    Inside Analog Photo
    http://www.insideanalogphoto.com

  7. #17
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    Scott;

    Looking forward to it myself.

    Give me a call beforehand, maybe Thursday or Friday this week?

    As for the subject, I would be glad to do anything you wish.

    Best wishes.

    Ron

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