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Thread: Scanning Resolution Question

  1. #111

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    Re: Scanning Resolution Question

    Quote Originally Posted by Corran View Post

    Well don't forget your popcorn. Or perhaps it's me who needs popcorn.

    I just scanned a 6x9 image from yesterday @ 4500 DPI (roughly the max it can go in one go) which is a retake of my 35mm image from in the creek on Monday. Even looking at what equates to a 15x enlargement it looks fantastic. I am tempted to print this one humongous. I probably don't have the wallspace for a 60x40. On the other hand I am closing on my house in about 3 weeks and that would be a nice addition...

    Anyway, [/blog]
    Bryan, at least you have to admit we get some fun !!!!

    Popcorn is always a good idea for all

  2. #112
    Peter De Smidt's Avatar
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    Re: Scanning Resolution Question

    Quote Originally Posted by Pere Casals View Post
    Hello Peter,

    Seybold report stated 5300 dpi optical performance for all the image width, so for 4" this is 1325dpi , for 1" this is amazing 5300 dpi.

    Attachment 166371

    http://www.kar.fi/Skannaus/pixelperf...ol28_nro11.pdf , page 16.
    And if you read more of the report, you'll see that the resolution went up in a measurably objective way from the purely optical resolution by scanning at higher values due to the quality of the positioning system. [But I see that Interneg already pointed that out pages ago. Time to find some coffee.]
    Last edited by Peter De Smidt; 22-Jun-2017 at 10:23.
    "Why can't we all just get along?" President Dale, Mars Attacks

  3. #113

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    Re: Scanning Resolution Question

    Quote Originally Posted by Peter De Smidt View Post
    And if you read more of the report, you'll see that the resolution went up in a measurably objective way from the purely optical resolution by scanning at higher values do to the quality of the positioning system. [But I see the Interneg already pointed that out pages ago. Time to find some coffee.]
    I've read very well that good report. You are referencing page 27 and 28 (http://www.kar.fi/Skannaus/pixelperf...ol28_nro11.pdf),

    so you speak about this table:

    Click image for larger version. 

Name:	cez2.jpg 
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ID:	166381


    This says that if you oversample (interpolation, with presumably further internal sharpening) then USAF 1951 resolution improves by a 15% linear, this also happens with ScanView ScanMate F8 Plus (it improves 6% with interpolation).

    So this says that for 4x5 with interpolation you get 1325 dpi * 1.15 = 1524dpi. For 8x10 this would be 762 dpi.

    Of course, this is without scanning strips and stitching in PS.

    I think I'm not wrong, please correct me if I made any mistake in my reasoning.

  4. #114

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    Re: Scanning Resolution Question

    Quote Originally Posted by Pere Casals View Post
    I've read very well that good report. You are referencing page 27 and 28 (http://www.kar.fi/Skannaus/pixelperf...ol28_nro11.pdf),

    so you speak about this table:

    Click image for larger version. 

Name:	cez2.jpg 
Views:	13 
Size:	51.6 KB 
ID:	166381


    This says that if you oversample (interpolation, with presumably further internal sharpening) then USAF 1951 resolution improves by a 15% linear, this also happens with ScanView ScanMate F8 Plus (it improves 6% with interpolation).

    So this says that for 4x5 with interpolation you get 1325 dpi * 1.15 = 1524dpi. For 8x10 this would be 762 dpi.

    Of course, this is without scanning strips and stitching in PS.

    I think I'm not wrong, please correct me if I made any mistake in my reasoning.
    You are wrong because you are assuming a linear scale that is not the case in reality. Just because resolution is limited at 6000ppi for 35mm, it does not linearly scale to 4x5. The Screen can capably resolve a sharp 2000ppi for 4x5 in one pass & more in multiple pass. If you were correct, the Imacon/ Hasselblads without the 8000ppi mode would not be able to resolve 2048ppi on 4x5 - yet somehow they can.

    You continue to refuse to acknowledge the obviously poor performance of the Epson in comparison with regard to aberrations & other crucial sharpness robbing characteristics.

  5. #115

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    Re: Scanning Resolution Question

    Quote Originally Posted by interneg View Post
    You are wrong because you are assuming a linear scale that is not the case in reality. Just because resolution is limited at 6000ppi for 35mm, it does not linearly scale to 4x5. The Screen can capably resolve a sharp 2000ppi for 4x5 in one pass & more in multiple pass. If you were correct, the Imacon/ Hasselblads without the 8000ppi mode would not be able to resolve 2048ppi on 4x5 - yet somehow they can.

    You continue to refuse to acknowledge the obviously poor performance of the Epson in comparison with regard to aberrations & other crucial sharpness robbing characteristics.

    Interneg, Flextight X5 also has a loss from the 8000 hardware pixels to 6900 optical. The loss is lower than the Cezanne because the hasselblad has a way better zoom lens.

    Here you have a 1951 scan form an X5:



    So see group and element, and check here https://en.wikipedia.org/wiki/1951_U...ion_test_chart this is 7-1 -> 128 (Perhaps 6-6 -> 114) Note (I see 128*25.4*2 = 6502 Lp/mm), they say 6900. So around that.


    ... while the X1 delivers 6150 for 35mm.


    Source: http://www.filmscanner.info/en/Hasse...extightX1.html


    Of course when zomming Cezanne to 4x5 (or 8x10) the resolving power for the 4" (or 8") will be lower than 5300/4 (or 5300/8) optical dpi this is an easy guess as zoom optics works worse in the long side of the focal range, as you may know.

    But I don't know at all how worse it will be, so I don't say it.


    Cezanne is a sound scanner for 35mm and 120, for 4x5 it has severe limitations, and for 8x10 we are talking of clear sub 1000 dpi. This comes from it's pre-press nature. A perfect gear for pre-press...


    Hasselblad was focused on 35mm and 120 format. They are 120 format people, as you know very well, so 4x5 capability comes as a bonus, not as the main target of the machine.

    About V750, this bell it would be from a 6m high monster print http://www.largeformatphotography.in...=1#post1395781

    poor performance ? not for me. Belive me, the Cezanne is way worse than the cheap V750 for 8x10, and way better for 35mm. (Not considering stitching).

  6. #116
    Peter De Smidt's Avatar
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    Re: Scanning Resolution Question



    [COLOR="#0000FF"][B] Belive me, the Cezanne is way worse than the cheap V750 for 8x10, and way better for 35mm. (Not considering stitching).
    Only if you use it poorly. If you use the Epson poorly, you'll also get subpar results. It's as if you were to evaluate the Epson, but not be willing to find the ideal scan height.

    I scan 8x10 on a Cezanne. Have you?
    "Why can't we all just get along?" President Dale, Mars Attacks

  7. #117

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    Re: Scanning Resolution Question

    Quote Originally Posted by Peter De Smidt View Post
    Only if you use it poorly. If you use the Epson poorly, you'll also get subpar results.
    Peter, I'm aware that if stitching strips, and if this results in a seamless image, then the result has to be awesome. But also there is no doubt that information I posted is fair, about those 5300 optical dots spreaded in 8 inches, if talking about 8x10.

  8. #118

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    Re: Scanning Resolution Question

    Thank ... for the Ignore button - it does wonders for some of the more contentious among us.

  9. #119

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    Re: Scanning Resolution Question

    Quote Originally Posted by Peter De Smidt View Post
    I scan 8x10 on a Cezanne. Have you?
    No, I've never scanned a 8x10 with a Cezanne, but as you did that, it would be great if you post an image to show how it does it, with and without stitching strips.

    I'm curious to see the practical difference from scanning straight or by joining strips with Cezanne.

    I mean a sample like this one, with a crop of the 1/20 height: http://www.largeformatphotography.in...=1#post1395781

    I know Cezanne does a very good job for 35mm and 120, but I'd like to know how it does with 8x10 without joining strips.


    Quote Originally Posted by Jim Andrada View Post
    Thank ...
    Jim, I don't care. If you can point a single mistake in what I posted I'd be happy to learn.

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