Page 14 of 16 FirstFirst ... 41213141516 LastLast
Results 131 to 140 of 155

Thread: side by side comparison... large print digital back VS 4x5 color film

  1. #131

    Join Date
    Feb 2002
    Posts
    783

    Re: side by side comparison... large print digital back VS 4x5 color film

    >Many observations lead me to accept Ctein's criterion of 30 lp/mm as necessary for "perfect sharpness" in a print.


    Sal, Ctein's test, it must have been 10 years ago, really rocked me. You are the first person who ever referenced it! Of course, other than contact prints, there is no chance of getting this level of detail into a print. I applaud your high standards!!

  2. #132
    Sheldon N's Avatar
    Join Date
    May 2006
    Location
    Portland, OR
    Posts
    605

    Re: side by side comparison... large print digital back VS 4x5 color film

    I was curious about the reference to Ctein's 30 lp/mm figure as necessary for ultimate print sharpness. I did some quick searching and found this recent article by him...

    http://theonlinephotographer.typepad...ill-a-vis.html

    He states that under normal print viewing conditions, the resolution limits of human vision are around 5 lp/mm. However, he states that we are far more adept at discerning acutance even if we can't see the resolution. He also states that "acutance trumps resolution and detail".

    Given this, wouldn't the proper control of acutance be the determining factor in the appearance of a print, rather than going up to 30 lp/mm?

  3. #133

    Join Date
    Sep 2003
    Location
    South Carolina
    Posts
    5,505

    Re: side by side comparison... large print digital back VS 4x5 color film

    That study has come up before as I recall discussing it on a thread here a year or two ago.

    It should be noted that 30 lp/mm is obtainable only with contact printing, with a negative that has at least that much information, and only on some silver gelatin papers. It would not be possible in contact printing with platinum and palladium because the texture of the art papers that are used with these processes limit resolution to around 10 lp/mm, or less.

    It would be almost impossible to get 30 lp/mm on silver paper when printing by projection, unless printing same size as the negative or at least by no more than about 2X.

    Sandy

    Quote Originally Posted by bglick View Post
    >Many observations lead me to accept Ctein's criterion of 30 lp/mm as necessary for "perfect sharpness" in a print.


    Sal, Ctein's test, it must have been 10 years ago, really rocked me. You are the first person who ever referenced it! Of course, other than contact prints, there is no chance of getting this level of detail into a print. I applaud your high standards!!

  4. #134

    Join Date
    Nov 1999
    Location
    San Clemente, California
    Posts
    3,804

    Re: side by side comparison... large print digital back VS 4x5 color film

    Quote Originally Posted by Sheldon N View Post
    ...wouldn't the proper control of acutance be the determining factor in the appearance of a print, rather than going up to 30 lp/mm?
    Ctein's results indicated that 30 lp/mm was necessary to provide an appropriate level of acutance. My observations agree.

  5. #135

    Join Date
    Feb 2002
    Posts
    783

    Re: side by side comparison... large print digital back VS 4x5 color film

    > Given this, wouldn't the proper control of acutance be the determining factor in the appearance of a print, rather than going up to 30 lp/mm?


    Sheldon, in general, I fully agree. Of course, both would be nice, but we must be realistic. The largest factor of sharpness for humans vision seems to be extreme edge sharpness and contrast in the 3 - 5 lp/mm range. This is not in conflict with Cteins findings that human vision can discern resolution up to 30 lp/mm. They are two different findings. Sort of, two ways to skin a cat....

    What would be interesting, a test with two images, one a contact print at 30 lp/mm, and a 5 lp/mm print with extreme edge sharpening, and see what the consensus is... My guess is, there would be no consensus, it would be hard to determine which is sharper. Before digital, only one option has been available to us...

    I think the radial target comparison on the link provided demonstrates how powerful edge sharpening can be. Specially when you view from 10ft back. In addition to edge sharpening, digital has the ability to add contrast, which can sometimes be as powerful as edge sharpening. There is many who still believe you can never add resolution to the initial capture.... and maybe by the truest definition of resolution, this is true, but who cares about the terminology...in the end, digital manipulation can truly add a great deal to "perceived sharpness".....which IMO, is all that matters - assuming sharpness is the goal, pinhole photographers do not apply.

  6. #136

    Join Date
    Feb 2002
    Posts
    783

    Re: side by side comparison... large print digital back VS 4x5 color film

    > Ctein's results indicated that 30 lp/mm was necessary to provide an appropriate level of acutance.


    Sal, IIRC, Cteins test was done long before digital manipulation / printing was good enough to test edge sharpening and contrast vs. pure on-film-resolution (contact print). I never performed side by side scientific type comparisons, but it sure would be great experiment. My guess is, digital manipulation would be more powerful than most think.

  7. #137
    Moderator
    Join Date
    Jan 2001
    Posts
    8,640

    Re: side by side comparison... large print digital back VS 4x5 color film

    The article describing Ctein's test results is "Is Your Print Paper Sharp Enough", in the March-April 2002 issue of Photo Techniques magazine. He tested nine different B&W papers, as well as different grades for both graded and VC papers, and found that every one could record well above 30 lp/mm.

    We've had this discussion before. Regardless of what techniques one employs in digital processing, the available printers - inkjet, laser on traditional papers, whatever - can't put anywhere near that kind of detail on paper.

    A digital print at 5 lp/mm to which extreme edge sharpening has been applied will look like a digital print at 5 lp/mm to which extreme edge sharpening has been applied. It's akin to what some users of traditional B&W film like to do with development techniques that exaggerate edge-and-adjacency effects. The prints will certainly capture one's attention from ten feet back.

    I'm with Sal on this.

  8. #138

    Join Date
    Sep 2003
    Location
    South Carolina
    Posts
    5,505

    Re: side by side comparison... large print digital back VS 4x5 color film

    Development procedures such as stand and other minimal agitation techniques that enhance adjacency effects are not as flexible as digital sharpening but they can still be very powerful. I have a 12X17 carbon transfer print that was made from a digital negative by contact printing. It is one of the sharpest photographs I have ever seen, for two reasons. One, the scene has some features that show high surface relief, which accentuates the impression of detail, and two, the film was developed with extreme minimal agitation to enhance adjacency effects. The sharpness is startling and people who have seen it comment that I must have used unsharp mask in preparing the digital file, but in fact I used no sharpening at all and the line effects are due entirely to surface relief and to the method of development.

    If I did the numbers this print really does not have nearly as much detail as one would think. It was made with a 6X9 cm HP5+ negative, scanned at only 2540 spi, and magnified about 6X. This limits detail to a maximum of about 10 lp/mm, and the negative, which was printed on an Epson 3800, would reduce resolution even more. But when I look at this print from a distance of about 12-15 inches it looks sharper than any contact print I have ever made from a LF or ULF negative.

    However, in general I agree with Sal and Oren in that silver prints made directly from LF and ULF cameras look a lot sharper to me than the best inkjet prints I have seen.

    Sandy King




    Quote Originally Posted by Oren Grad View Post
    T
    A digital print at 5 lp/mm to which extreme edge sharpening has been applied will look like a digital print at 5 lp/mm to which extreme edge sharpening has been applied. It's akin to what some users of traditional B&W film like to do with development techniques that exaggerate edge-and-adjacency effects. The prints will certainly capture one's attention from ten feet back.

  9. #139

    Join Date
    Oct 2005
    Location
    Santa Cruz, CA
    Posts
    2,094

    Re: side by side comparison... large print digital back VS 4x5 color film

    Quote Originally Posted by sanking View Post
    However, in general I agree with Sal and Oren in that silver prints made directly from LF and ULF cameras look a lot sharper to me than the best inkjet prints I have seen.
    Sandy King
    I'll have to go look and see. I'm not sure I would agree. There are a lot of factors. However, I will add that when I was printing primarily in platinum I used a very thin paper, a version of Bienfang Graphics without the OBA's. In the drying process, after washing, it shrank quite a bit, and made for some very sharp looking prints...

    Lenny
    EigerStudios
    Museum Quality Drum Scanning and Printing

  10. #140

    Re: side by side comparison... large print digital back VS 4x5 color film

    Sandy, your eyes are not lying to you. The two processes have different capabilities. Silver (depending on source) has the capability to resolve more and also carry more micro levels of gray, even than the best current inkjet system.
    Just toggle between the silver contact and K7 2880 on this page-

    http://www.custom-digital.com/info/B...ity/index.html

    It's quite clear. Inkjet is still a halftone process, though complex and very high quality.
    This is not meant to be a judgement, these differences show to the eye very differently under different circumstances, sometimes irrelevant.
    Sometimes inkjet can look sharper simply because the dots themselves are sharp forcing a hard edge. But the fact remains that more actual photographic information from the source is getting to paper with silver than with inkjet... and I love inkjet for other reasons...
    Complicated.
    Tyler
    http://www.custom-digital.com/

Similar Threads

  1. "Digital 4x5"?
    By Eric Leppanen in forum Digital Hardware
    Replies: 11
    Last Post: 18-Jul-2005, 22:59
  2. Grafmatic 6 sheets 4x5 film folder
    By NG Sai-kit in forum Cameras & Camera Accessories
    Replies: 8
    Last Post: 25-Dec-2001, 11:18
  3. Digital printing 6x9 vs 4x5
    By Glenn Kroeger in forum Digital Hardware
    Replies: 19
    Last Post: 22-Feb-2000, 13:42
  4. 4x5 best optics w/ Scheider HIGH END BACK sharper than 8x10?
    By Bill Glickman in forum Cameras & Camera Accessories
    Replies: 11
    Last Post: 17-May-1999, 04:31
  5. 4x5 digital camera back
    By Peter Tucker in forum Digital Processing
    Replies: 1
    Last Post: 26-May-1998, 15:30

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •