Page 3 of 6 FirstFirst 12345 ... LastLast
Results 21 to 30 of 55

Thread: Resolution loss from transparency to print

  1. #21

    Join Date
    Jul 2007
    Location
    Austin TX
    Posts
    2,052

    Re: Resolution loss from transparency to print

    Jac, by a strictly academic answer and with no enlargement at the paper, the chain of lp/mm you cite would result in about 22 lp/mm at the enlarging paper at 1:1. Each doubling of the enlargement halves the lp/mm at the paper.

    Of course per the above arguments, all of which I think have a degree of validity, there is a lot more to the comparison than just academics.

    For me, how the textural and fine detail of the original scene is preserved through the entire workflow is important in some cases. If the film original contains the desired level of detail then from my experience the best replication is obtained from a high quality optical system. I tend to agree with Drew on this.

    OTOH I find a scanning digital workflow utilizing a 2000 nominal spi scan, for example, with judicial sharpening in PS can actually appear to be a sharper print. For some images I prefer this. My problem is that the digitally enhanced sharpness is to some degree artificial in that it does not replicate the fine detail or microcontrast in the original scene (or on film) like a high quality enlarging lens can. This is particularly true using a fairly high contrast enlarger.

    I would certainly cite the Ilfochrome work of Chris Burkett for state of the art in optical reproduction but I also work with Ilfochrome and 2000 spi scanning and would generally confirm what I said above.

    I'm not sure the difference is at all significant when we consider very high quality drum scanning in comparison to an all optical workflow.

    Nate Potter, Austin TX.

  2. #22
    Jac@stafford.net's Avatar
    Join Date
    Dec 2012
    Location
    Winona, Minnesota
    Posts
    4,084

    Re: Resolution loss from transparency to print

    Thank you all for the good discussion.

    Visual intelligence, or how humans perceive is an academic interest of mine. I had the privilege of working with some excellent psychologists (the perceptual kind, not shrinks) and others in the sciences. One of the things that came up in conversation makes me wonder if having been a photographer and darkroom printer for forty years has changed the way I perceive some things, in particular I do not perceive the Cornsweet illusion. Nor is my vision confused by certain black-and-white tonal differences caused by surrounding and adjacencies. Has anyone else here a similar experience?

    Note that I am still entirely susceptible to confusions of colors caused by surrounds and adjacencies. I have normal to excellent color perception, but not as good as the 1% who have the best. (I do very little color photography.)

    Aside: A friend of mine is an accomplished, published documentary photographer. He does all 'straight photography' in MF and 6x17cm. At a show I mentioned to him that his prints were soft on the left edge and he responded, "That's the kind of thing only a photographer would notice." I think our discussions are very much along the same line. It is a good thing.

  3. #23
    Drew Wiley
    Join Date
    Sep 2008
    Location
    SF Bay area, CA
    Posts
    10,593

    Re: Resolution loss from transparency to print

    You can simply bypass a lot of the MTF calculations with a simple analogy. You have a lens on a view
    camera (some better than others), then a piece of polyester or acetate film on the back. You expose it.
    IF the film was flat, properly focussed etc. you view that on a lightbox under a high-power magnifier
    and can often see a LOT of detail. Same principle at the enlarging station. Now look thru a loupe at
    an inkjet print or lightjet print or a typical substrate. Not much there. This isn't about how good it looks
    to an ordinary viewer (which might be fine) but about the academic ability to hold resolution. All the
    number crunching in the world won't change that. You are only as good as your weakest link. A proper
    optical system, given a highly detailed oringal neg or transparency, will transfer virtually all that information onto an equivalent polyester photosensitive surface. Paper and ink cannot. Again, none of
    this is about esthetics, but simply why splitting hairs over published MTF data is a very minor issue
    compared to the other problems in reproduction.

  4. #24

    Re: Resolution loss from transparency to print

    Hey Drew,
    That last analysis cleared up my question. Thanks
    Now, is there anywhere on the planet where darkroom printing is still done?
    Jim

  5. #25
    Abuser of God's Sunlight
    Join Date
    Aug 2004
    Location
    brooklyn, nyc
    Posts
    5,774

    Re: Resolution loss from transparency to print

    The proof may be in the pudding, Drew, but you haven't offered any. Just personal attlacks. I've invited anyone in the NYC area to come to my studio to look for themselves.

    You say my enlarging settup was primitive; I'd love to hear about a more advanced one. But for the sake of argument, I'll agree, and just let people compare my inkjet prints to contact prints from the same negatives. I'll even put 3X enlarged ink prints against contact prints from the same negative.

    Ascertaining sharpness by looking through a loupe is just blowing smoke; sharpness is highly size dependent. This wasn't obvious with analog tools, although people sensitive to the process who used staining developers and other techniques that produce edge effects figured this out. Digital tools make it obvious to anyone.

    You're incorrect in saying you can't add sharpness. I believe you mean that you can't add detail, which is not at all the same thing. Sharpness is a subjective quality, and it's influenced primarily by MTF at a particular range of spatial frequencies. This can increased or reduced with great control.

    I'm offering pudding for proof to anyone curious.

  6. #26
    Drew Wiley
    Join Date
    Sep 2008
    Location
    SF Bay area, CA
    Posts
    10,593

    Re: Resolution loss from transparency to print

    Paul - edge enhancement can be done all kinds of ways and is not the same thing as preserving detail. This is a bit academic
    obviously, because if no one really sees micro-detail in the final print, is a mum subject. I do like it when one can work at the
    visible limits however. Place a microfilm target in the glass neg carrier and then a piece of high resolution film on a vac easel
    and print that and look at it through a high-power loupe or low power microscope. That starts telling you what optics can really do. Way back in the 1930 they were having contests seeing who could put the most number of complete texts of the
    Bible on a microdot, and even back then there were film and lenses that could do about thirty! Of course, full scale tonality
    photography is a somewhat different subject. I really don't care how someone chooses to print their own work, and there are
    many viable specific media. The only issue I have is folks who go around waving their arms and screaming that newer technology trumps everything simply via its novelty. Then they jump thru a lot of software hoops attempting to imitate what
    was done better a century ago using primitive techniques. In your case, you've been implying that digital printing actually
    has some kind of edge relative to sharpness - and that would have bordered on nonsense a hundred years ago. Maybe it's
    easier for things like squirrely 120 films, but there are all kinds of means of analog printing, which don't have the same
    output bottenecks that color digital printing does (per resolution that is). Black and white work can be done a little more
    precisely, esp by folks with serious prepress and press gear, but millions of bucks put even into that game won't match a
    basic 8x10 contact print done correctly. It's technologically impossible. And don't go thinking we Calif folks who are a bunch
    of hicks who don't understand what that means. If I want to see world class inkjet or laser printed work I can do so almost
    in walking distance. Some of it gets installed in your city for huge sums. I work with some of these folks supplying them specialty gear and chatting esthetic strategy, and you'd be pretty amazed what they can come up with, as well as with their equipment and facilities.

  7. #27
    Drew Wiley
    Join Date
    Sep 2008
    Location
    SF Bay area, CA
    Posts
    10,593

    Re: Resolution loss from transparency to print

    Oh but Paul - please keep this in perspective. It's a tech debate, and I in no manner whatsoever am implying I don't like your
    work in an esthetic sense, or wouldn't admire your own prints in person. And yes, it is kind to invite me to view it in person,
    which I would do if I ever had opportunity.

  8. #28

    Re: Resolution loss from transparency to print

    Edge enhancement, up sampling or etc in post process does not increase the actual amount of information. If this held true then perpetual motion would be real and current information theory has been proven false. These processes can never equal real amounts of information acquired.

    It seems the current norm for computer based printing is something like 300 dpi which translated to a dot size of 0.0033". In order to meet the Nyquist criteria for conveying stored information two points are required which means the actual smallest area possible to convey information would be 2x 0.0033" or 0.0066".

    The average thickness of a human hair is 0.004".. which is quite visible to most individuals when places on a sheet of white paper at a distance of 12".

    Point being, there is far more to image quality than simple lines per mm, dots per inch or any other highly simplified metric of visual acuity. How and the way we see is far more complex than that.

    High resolution or information content alone does not make an expressive image.. it takes far more than just these metrics.


    Bernice


    Quote Originally Posted by Drew Wiley View Post
    Paul - edge enhancement can be done all kinds of ways and is not the same thing as preserving detail. This is a bit academic
    obviously, because if no one really sees micro-detail in the final print, is a mum subject. I do like it when one can work at the
    visible limits however. Place a microfilm target in the glass neg carrier and then a piece of high resolution film on a vac easel
    and print that and look at it through a high-power loupe or low power microscope. That starts telling you what optics can really do. Way back in the 1930 they were having contests seeing who could put the most number of complete texts of the
    Bible on a microdot, and even back then there were film and lenses that could do about thirty! Of course, full scale tonality
    photography is a somewhat different subject. I really don't care how someone chooses to print their own work, and there are
    many viable specific media. The only issue I have is folks who go around waving their arms and screaming that newer technology trumps everything simply via its novelty. Then they jump thru a lot of software hoops attempting to imitate what
    was done better a century ago using primitive techniques. In your case, you've been implying that digital printing actually
    has some kind of edge relative to sharpness - and that would have bordered on nonsense a hundred years ago. Maybe it's
    easier for things like squirrely 120 films, but there are all kinds of means of analog printing, which don't have the same
    output bottenecks that color digital printing does (per resolution that is). Black and white work can be done a little more
    precisely, esp by folks with serious prepress and press gear, but millions of bucks put even into that game won't match a
    basic 8x10 contact print done correctly. It's technologically impossible. And don't go thinking we Calif folks who are a bunch
    of hicks who don't understand what that means. If I want to see world class inkjet or laser printed work I can do so almost
    in walking distance. Some of it gets installed in your city for huge sums. I work with some of these folks supplying them specialty gear and chatting esthetic strategy, and you'd be pretty amazed what they can come up with, as well as with their equipment and facilities.

  9. #29
    Format Omnivore Brian C. Miller's Avatar
    Join Date
    Jun 1999
    Location
    Everett, WA
    Posts
    2,961

    Re: Resolution loss from transparency to print

    Quote Originally Posted by january112013 View Post
    Any recommendations on neg film?
    Jim
    I just realized that nobody answered this. Ektar 100 is currently "king" for finest grain. However, you should really use this film with a color meter, and balance the film with appropriate filters when you are exposing it. However, do try Portra. It's an artistic call, and a certain subject or scene might be suited to it better.

    As for current darkroom work, there are a large number of B&W commercial printers producing up to 20x24. (I know there was a lab in NYC that printed larger, but they don't appear to be doing that any longer.) For larger work, Bob Carnie on the forum prints larger B&W. I don't know about color, so perhaps someone can chime in about a commercial lab which still prints color with an optical-chemical path.
    "It's the way to educate your eyes. Stare. Pry, listen, eavesdrop. Die knowing something. You are not here long." - Walker Evans

  10. #30
    Abuser of God's Sunlight
    Join Date
    Aug 2004
    Location
    brooklyn, nyc
    Posts
    5,774

    Re: Resolution loss from transparency to print

    We all agree that there's more to a print than detail, sharpness, and resolution ... which I am not listing as synonyms, because they are not.

    This thread brought up issues of what the eye can see, which is what I'm addressing. I have divided this into two separate questions, because "what the eye can see" and "what makes a print look sharp, detailed and clear" are only distantly related, even though we often conflate them.

    When I'm talking about sharpness, which is a major component of perceived image quality, I'm talking about a perceptual quality. Imaging scientists and perceptual psychologists start with perception. Like, if 19 out of 20 test subjects said that print A looked sharper than print B. The technicians then find which measureable qualities correlate with that impression.

    Old fashioned metrics like total detail and maximum extinction resolution do not correlate. A print that only resolves 6 lp/mm can appear radically sharper and more detailed than one which resolves 30 lp/mm. The eye can't see all that detail, and the detail that it uses to form its impression of image quality is much lower frequencies: 1 to 5 lp/mm. This is why MTF curves have replaced resolution numbers when discussing optical quality.

    The higher resolutions matter if you're looking through a loupe or a microfiche machine. This can be significant for some uses, but not for normal viewing of photographs.

    My contact prints contain much, much more recoverable detail than my similar sized ink prints from the same negative. But the ink prints appear more sharp and detailed at normal viewing distances. The fact that they are storing less detail is irrelevant, because that added detail is not visible.

    Drew keeps saying that my claims are "impossible," but the results are easily visible to anyone who wants to look. The optical science explaining this is also unequivocal, and is easy to lay your hands on today.

Similar Threads

  1. Printing Service that will print a 16x20 or larger Transparency
    By mcallisk in forum Digital Processing
    Replies: 8
    Last Post: 31-Dec-2012, 18:06
  2. Format- Print vs Transparency
    By Greg Liscio in forum Darkroom: Film, Processing & Printing
    Replies: 11
    Last Post: 13-Nov-2009, 09:23
  3. How to print high resolution From Autocad?
    By luis_ortho in forum Darkroom: Film, Processing & Printing
    Replies: 0
    Last Post: 20-Dec-2006, 09:03
  4. Print Quality Via 4X5 transparency /Scanned/Photoshop/Digital Printed
    By Al Cherman in forum Darkroom: Film, Processing & Printing
    Replies: 9
    Last Post: 4-Feb-2002, 16:30
  5. Resolution increases with print size?
    By Douglas Broussard in forum Darkroom: Film, Processing & Printing
    Replies: 11
    Last Post: 20-Jul-2000, 13:00

Tags for this Thread

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
  •