Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 68,671   Posts: 1,481,796   Online: 1092
      
Page 5 of 19 FirstFirst 123456789101115 ... LastLast
Results 41 to 50 of 182
  1. #41
    Stephen Benskin's Avatar
    Join Date
    Jan 2005
    Location
    Los Angeles
    Shooter
    4x5 Format
    Posts
    1,196
    Quote Originally Posted by markbarendt View Post
    Regarding the "under" curve I've drawn "it does not get enough camera exposure" to create detail on the negative for my chosen zone III subject matter, it is showing how a failure/operator error/scrimping on exposure might lose detail. The film curve in my diagram remains pegged to where my chosen subject matter falls or in this case fails to fall..
    So, those aren't actual film curves? With underexposure, the film curve will still have a Zone III, just not at the same point on the curve as it would with normal exposure. A sliding gray scale would work better for what you are wanting to illustrate. How are you planning to define print Zones? An overexposed negative can be printed down. Will this be taken into account or will it re-enforce the notion that a specific negative density is required to produce a specific print reflection density?

    Essentially the same lines as your windmills show between Q1&Q4, I'm moving those two quadrants apart and superimposing possible negative curves between them. There is also one other big difference, the lines are meant to show the photo I want at either end regardless of negative exposure.
    It sounds more like they represent print Zones.
    Last edited by Stephen Benskin; 04-17-2013 at 07:40 AM. Click to view previous post history.

  2. #42
    Stephen Benskin's Avatar
    Join Date
    Jan 2005
    Location
    Los Angeles
    Shooter
    4x5 Format
    Posts
    1,196
    Quote Originally Posted by Photo Engineer View Post
    Haist has done it more simply!
    Ron, could you upload an example. Modern Photographic Process is one set of books I don't have (too expensive).

  3. #43

    Join Date
    Feb 2010
    Location
    Montreal, Canada
    Shooter
    Multi Format
    Posts
    4,253
    I will try to scan an example from Haist today.

    I think what Mark is trying for in his sketch is to sort of simplify the tone reproduction illustration by essentially fixing all the variables except negative exposure. Somehow that is all modeled and fixed into the horizontal lines so that you then move the paper curve up and down and the shift directly reflects the change in negative exposure without showing the transitions. I think.

    My thought is that this is similar to combining the windmill with a Dorst for the transition between subject and negative. Jones and Dorst diagrams can of course be combined (there is an example in Henry).

    Or I may be out in left field.

  4. #44
    markbarendt's Avatar
    Join Date
    May 2008
    Location
    Ignacio, CO, USA
    Shooter
    Multi Format
    Posts
    5,278
    Blog Entries
    3
    Images
    19
    Quote Originally Posted by Stephen Benskin View Post
    So, those aren't actual film curves? With underexposure, the film curve will still have a Zone III, just not at the same point on the curve as it would with normal exposure. A sliding gray scale would work better for what you are wanting to illustrate. How are you planning to define print Zones? An overexposed negative can be printed down. Will this be taken into account or will it re-enforce the notion that a specific negative density is required to produce a specific print reflection density?
    Correct, they are not actual curves, as I said from the start, this is a rough illustration of an idea.

    If I pick a specific subject in a scene that I want to print as zone III on paper it is very possible because an underexposure to get a negative with no usable info for that subject, no detail just black. Its a demonstration of the classic advice we all get that with an underexposure detail is truly lost.

    With that same subject defining zone III the other three curves have zone III but at different densities.

    Defining or pegging print zones in my example is very much done as Adams might have, looking at a scene, deciding what range to pick and picking certain subject matter and saying I want that to fall in such and such zone.

    Printing the curves I labled as box and extra would require different enlarger exposures.

    The value I see in consistent negative density for a given zone is not addressed by my illustration. That is more a matter of working efficiently.
    Mark Barendt, Ignacio, CO

    "We do not see things the way they are. We see things the way we are." Anaïs Nin

  5. #45
    markbarendt's Avatar
    Join Date
    May 2008
    Location
    Ignacio, CO, USA
    Shooter
    Multi Format
    Posts
    5,278
    Blog Entries
    3
    Images
    19
    Quote Originally Posted by Michael R 1974 View Post
    I will try to scan an example from Haist today.

    I think what Mark is trying for in his sketch is to sort of simplify the tone reproduction illustration by essentially fixing all the variables except negative exposure. Somehow that is all modeled and fixed into the horizontal lines so that you then move the paper curve up and down and the shift directly reflects the change in negative exposure without showing the transitions. I think.

    My thought is that this is similar to combining the windmill with a Dorst for the transition between subject and negative. Jones and Dorst diagrams can of course be combined (there is an example in Henry).

    Or I may be out in left field.
    Close Michael,

    What I'd say is that I'm not moving the paper curve, its fixed in relation to the scene. The variable is strictly the negative. The negative doesn't define zones, its just a transfer medium.
    Mark Barendt, Ignacio, CO

    "We do not see things the way they are. We see things the way we are." Anaïs Nin

  6. #46

    Join Date
    Feb 2010
    Location
    Montreal, Canada
    Shooter
    Multi Format
    Posts
    4,253
    Oh, ok. I thought those were paper curves in the diagram. Sorry about that.

    Can someone let me know where this is in Haist? I didn't remember anything about tone reproduction being in the sensitometry section at the end of Volume 1 (the Sensitometry section is excellent, by the way, and details not only ISO test methods but also addresses some of the problems involved in both sensitometry and image evaluation). But there is nothing really about tone reproduction.

    Is it somewhere in Volume 2? I haven't had a chance to check.

  7. #47
    markbarendt's Avatar
    Join Date
    May 2008
    Location
    Ignacio, CO, USA
    Shooter
    Multi Format
    Posts
    5,278
    Blog Entries
    3
    Images
    19
    No problem Michael you guys are being a big help in forcing me to think.
    Mark Barendt, Ignacio, CO

    "We do not see things the way they are. We see things the way we are." Anaïs Nin

  8. #48

    Join Date
    Aug 2006
    Location
    Magnificent Rockies
    Shooter
    35mm
    Posts
    528
    Images
    1
    Quote Originally Posted by Photo Engineer View Post
    Haist has done it more simply!

    PE
    Ron, I would also be very interested in what Haist had to say!
    -Fred

  9. #49
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    22,707
    Images
    65

    Graphs from Haist

    The verbal discussion of this covers several pages in Haist and in Mees as well. I am going to post 2 examples showing latitude of a print vs the position of the exposure on the negative. The Density Range is what will be captured on the print shown in my earlier post.

    PE
    Attached Thumbnails Attached Thumbnails Haist exposure range 1.jpg   Haist exposure range 2.jpg  

  10. #50

    Join Date
    Feb 2010
    Location
    Montreal, Canada
    Shooter
    Multi Format
    Posts
    4,253
    Ok these are from the sensitometry chapter at the end of Volume 1 for those following along in the book. But this isn't really tone reproduction theory/models (ie "end to end" system).



 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin