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Discussion in 'B&W: Film, Paper, Chemistry' started by Aggie, May 22, 2003.

  1. Aggie

    Aggie Member

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  2. Loose Gravel

    Loose Gravel Member

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    The area of the neg that prints the shadows is the lower left and the highlights (the high densities) is the upper right of the 'curve'.

    I think there are too many film/dev combos out there to say one is best for this or that. It is more likely that there are so many that are fine and that do not limit our ability to make a photograph. Pick one film/dev and stay with it. Learn to understand it in different lighting situations. I know you are using PMK. I use this and think it works great, although sometimes I feel as though it is way harder than it should be. But I invested much time to get it to work and I'm sticking with it. I use HP5+ for all my formats: 35mm to 5x7. People tell me all the time to try this film or that for better grain or because... I don't know why. It think it is because we all feel that we will make better photos if we are using the same stuff. But if I'm using a 57, why would I care about grain? I need all the speed I can get. If I'm using 35mm, I use it because it for its speed and spontaneity, and if I have more time, I'll use a bigger camera on a tripod. You know what, HP5+ works for me and the last thing I need is another experiment. A good photographer can get just about any film to work. If your shadows are weak, give more exposure. I your highlights are blown out (can't happen with PMK) then cut back on development or use PMK.

    We all need to quick dorking around and take more photos.
     
  3. fhovie

    fhovie Subscriber

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    Sometimes these experiments lead back full circle. I tried HP5 and liked the look of the TRI X grain (little dots) better than the paisley looking smudged grain of HP5. HP5 looks LESS grainy though - Untill you are up close. Anyway - great shots are made on all kinds of combos every day.

    I think the graphs are useful when you consider how you want to expose and develop a shot. If the film can record 10 stops and you have a 5 stop image, where you place those 5 stops, near the toe or near the shoulder will impact not only the contrast but the linearity of the contrast. More development time makes the graph steaper and less development time makes the graph flatter. I tend to stay in the middle of the graph if I can. (That is my level of craft at the moment) I have no fear of changing the slope however. I might opt to increase my development to make those 5 ranges expand the the whole range of the film (a portrait or still life?) - Or - more often, I will lower the slope (landscapes) with a short development time and know that I have captured details I had not considered. - Then I can print them up if I need to. The film speed changes with the change in the slope though.

    Pyro and Catechol affect the shoulderof the slope. The tanning clamps the highlights by not letting fresh developer in after a certain amount of development has taken place. Metol based developers will cause less curve at the shoulder because they will permit more blocking in the highlights. It can almost seem like the highlights go out of focus due to the blocking.

    One thing I am sure of - one can spend their photo time in technology and have no time to create or capture beauty. Technology is good but sometimes even the greats would just guess and wing it!

    One last thing - grain and LF. I have shot TechPan, APX100 and TRI X in 4x5. The difference in the look of TechPan and TRI X is amazing. The Techpan is very very smooth and although you would not say the TRI X is grainy on a 16x20 print from a 4x5 negative, when you see them side by side - it is very apparent. Kind of like 8x10 contact prints I would guess. - Different when you compare -
    Frank
     
  4. Donald Miller

    Donald Miller Member

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    Aggie,
    The other thing that is involved with the characteristic curve of a film is the left vertical line of the characteristic curve graph is the net density, the lower horizontal line is the measurement in stops of exposure (zones). Therefore in comparing characteristic curves of films we can determine the length of the toe, where the shoulder occurs, and how pronounced it is.

    The reason for looking at the length of the toe is that since this is the shadow area of the film. We can look at this in terms of stops of light (zones) that are found on the toe. This is an area that does not separate tonalities well since the angle of the slope is much shallower then the straight line section that then follows.

    When we view the straight line, we can determine the severety of the angle (the amount of density added per stop of light exposure). This will depict the separation of the midtone values.

    When we view the shoulder we see at what point it begins to be introduced in relation to stops of exposure and how much it flattens. If it flattens markedly then any highlights that are recorded there will not be separated well in their tonality.

    If one were to compare a high contrast film such as tech pan we would see that this film has a fairly straight line from the toe to the shoulder. This film can tolerate a great deal of contrast expansion. (depending on the developer used and time of development). Conversely Tri X has a fairly long toe (reaching almost to zone III) and then has a fairly long straight line (zones III-XI). This film would not separate shadows well if it is exposed so that our lowest value is placed at a Zone I value.

    However, we can expose Tri X so that our low values are on Zone III. Because the exposure (in this example) has placed our low values on the straight line section of the film curve the shadows are better separated.

    Just as there are characteristic curves for films there are also characteristic curves for papers. In the case of paper, the toe area would be exactly reversed from film in that the highlights are represented on the toe and the highlights are represented on the shoulder.

    I think that a great deal can be learned about the characteristics of materials by viewing the manufacturers graphic depiction of those characteristics. Ultimately, of course, the defining parameter is what is shown in the print. Understanding our materials helps that process along.
     
  5. fhovie

    fhovie Subscriber

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    Don:

    I bet APX100 must have a real short toe then because of the great shadow separation I get with it. - I always put my important shadows in zone 3 anyway (that keeps me out of trouble with tri-x) - Frank
     
  6. Aggie

    Aggie Member

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  7. Donald Miller

    Donald Miller Member

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    Frank,
    Yes, I agree with your placement on TriX. Sometimes I even place my low value at Zone IV with TriX. Depending if I want to give an impression of great luminance in the scene. Of course, the other thing that enters is what EI one rates a film at. I have found through testing that TriX (prof) actually exposes in my system at an EI of 160. This gives me a zone I density of .10 density above fb+fog. The reason that I mention this is that if one person rates TriX at 320 and is giving a Zone III exposure for shadows and another rates it at 160 and gives a Zone III exposure, then the second is actually giving a Zone IV exposure based upon the first persons rating of 320.

    I think that John Sexton was once purported to have said "Nothing lives on Zone III". I have always observed a sense of luminance in his images. Perhaps that is why.
     
  8. fhovie

    fhovie Subscriber

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    I rate TRI X at 200. I don't have a densitometer but the results are good at N processing for a printable zone 1. Interesting quote about nothing living at zone 3. I am very unwilling to loose shadow detail.
     
  9. sanking

    sanking Member

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    Aggie,

    The main thing you need to know about the curve of PMK negatives is that it shoulders quite a bit. This can be a very good thing if you are photograhing a scene that has a lot of extended highlight detail because it will extend the range of printable highlights, and a not so good thing in scenes that require a lot of separation in the highlights.

    I have a question for Frank regarding the following statement. "Pyro and Catechol affect the shoulder of the slope. The tanning clamps the highlights by not letting fresh developer in after a certain amount of development has taken place."

    On what do you base this statement? I have done a lost of testing with both pyrogallol and pyrocatechin developers and it is not my experience that these developers affect the shoulder in any significant way that is different from traditional developers, except for the manner in which the stain color may impact VC papers. For sure PMK shoulders, but in my opinion this shouldering results from developer exhaustion, in the same way that a glycin-based developer like FX-2 shoulders, and not from any inherent tendency of pyrogallol as a reducing agentl to shoulder. The tests I have done with ABC Pyro, Rollo Pyro and Pyrocat-HD, which are much more energetic than PMK, do not show any sign of shouldering in the curves.

    Sandy




    Metol based developers will cause less curve at the shoulder because they will permit more blocking in the highlights. It can almost seem like the highlights go out of focus due to the blocking."


    Pyro and Catechol affect the shoulderof the slope. The tanning clamps the highlights by not letting fresh developer in after a certain amount of development has taken place. Metol based developers will cause less curve at the shoulder because they will permit more blocking in the highlights. It can almost seem like the highlights go out of focus due to the blocking.
     
  10. sanking

    sanking Member

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    I am having a very bad day with the APUG protocol for posting message, for which I apologize. The last two paragraphs of my last message are part of Frank's earlier message, not a new post by me

    Sandy
    .
     
  11. c6h6o3

    c6h6o3 Member

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    </span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (dnmilikan @ May 22 2003, 11:45 AM)</td></tr><tr><td id='QUOTE'> This gives me a zone I density of .10 density above fb+fog. </td></tr></table><span class='postcolor'>
    I have never understood why anyone cares about Zone I. It's density is not useful in any way since it's on the non-linear portion of the curve. Suppose you get a Zone I of .35 over f+b How do you adjust it? And even if you do find the "proper" .1 over f+b, it tells you nothing about how to adjust for the zones you do care about; namely zones III-VIII.

    Before I standardized on a staining developer I used to test a new film by finding the exposure index which would get zone III up off the toe. Then I starting using pyro and now I just print them on a Grade 2 paper and judge the local contrast. My prints are much better for it.
     
  12. David A. Goldfarb

    David A. Goldfarb Moderator Staff Member Moderator

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    I think the original idea behind using a Zone I density of .1 over film base plus fog, or to find the minimum exposure necessary to produce a meaningful increase in density, was to produce the thinnest (and therefore sharpest) possible negative with the tonality desired, and to be able to use as much of the density range as possible for N+ development before hitting the Dmax.

    If you get a Zone I density of .35, you adjust it by increasing your film speed rating.

    On the other hand, your reason for testing for Zone III instead of Zone I seems perfectly valid to me. The only thing you may lose by doing it that way is the potential for N+ development if you place it too high, and depending on the film, format, and enlargement plans some small degree of sharpness, but that seems like a worthwhile tradeoff, if it gives you the tonality you want for N development.
     
  13. c6h6o3

    c6h6o3 Member

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    </span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (David A. Goldfarb @ May 23 2003, 04:15 AM)</td></tr><tr><td id='QUOTE'> was to produce the thinnest (and therefore sharpest) possible negative with the tonality desired, </td></tr></table><span class='postcolor'>
    Illogical. Zone I tells you nothing about tonality. Finding your film speed is all about scale over the entire range, not about thresholds at either end.

    All Zone I gives you is the thinnest possible negative. But it's that "with the tonality desired" part that's important, not how thin it is.
     
  14. David A. Goldfarb

    David A. Goldfarb Moderator Staff Member Moderator

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    I wasn't suggesting that the Zone I test told anything about tonality on its own, just that achieving the desired tonality is the goal of using the zone system, and maximizing the full density range was part of the goal.

    It isn't entirely irrelevant, because if you place Zone I too high, and for a certain lighting situation you want N+4 (presuming the film is capable of that, which was more likely in the early days of the zone system), then you might not be able to get it, because you will have "wasted" the toe of the curve or effectively, you will have reduced your Dmax.
     
  15. mvjim

    mvjim Member

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    One thing that I believe would help, many in threads such as this, is to mention what format you are generaly using. What might be the hot thing for 8 X 10 negs might not be the thing you would suggest for 35 mm. One thing I do know is that once someone starts producing "good" negs their usual first response is that the negs look too thin compaired to what they have been making reguardless of the developer or exposure technique used.
     
  16. fhovie

    fhovie Subscriber

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    To catch up here ... Sandy - My testing shows a difference in the shouldering of any panchromatic film developed in PMK - if that differes from your testing - so be it.

    Zone 1 is important to me - There are certain things I look for in a negative and without zone 1 it would not be what I am looking for. So - I strive for a printable zone 1 - I also want the thinnest negative I can get and still keep zone 1 - I notice a degradation in sharpness in dense negatives. Zone 1 is like 1db - (if you have good hearing you can just hear 1db) you can just perceive zone 1 - it is near black - it has no other information other that adding one more color to the photo. I want that color - so I care about zone 1. I get zone 1 by knowing my film speed with a particular combination from film to paper including all chemistry and a particular light meter. I meter zone 3 for anything I want to retain texture in the very darkest areas and let everything else fall into place. I take into consideration total range based on high and low spot meter readings and decide if I will need to deveolp at N- or N+ (And I know how that manipulatio will change film speed)

    There is definately a difference in the way 35mm an 4x5 catch light and print - My development times are different - the emulsions are different - (eg. TRI X in 35mm has no antihalation layer that I can detect in the prewash - 120 and 4x5 versions have a dense blue antihalation layer) My expectations of each film get adjusted. - I never expect a 35mm to make a great 11x14 print. (Except TechPan) So If the image is going to go big - I use big film. I also think you can get away with a lot more on big film. There is much less enlargement and much more information captured. Kind of a benefit. Tanning developers and LF film give me a "look" that works for the kind of things I like to capture. I was very unhappy with PMK on 35mm and am back to a more common strain of the benzine ring for that.

    Truely though, I look at my images and their impact is more from composition and timing than from what chemical I use. The subtle improvements from chemistry just add a different feeling to what is already going on - (Except of course the 50W lit filament in a lightbulb I photographed that was clamped by DiXactol allowing me to read the wattage printed on the glass of the bulb.)

    Frank
     
  17. sanking

    sanking Member

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    Frank,

    The issue not whether PMK shoulders. I know that it does, and have previosly described shouldering as am important characterisctic of PMK.That has nothing to do with my question.


    The issue is what you wrote in an earlier messasge, to wit.

    "Pyro and Catechol affect the shoulder of the slope. The tanning clamps the highlights by not letting fresh developer in after a certain amount of development has taken place. Metol based developers will cause less curve at the shoulder because they will permit more blocking in the highlights. It can almost seem like the highlights go out of focus due to the blocking."

    You appear to be saying that both pyrogallol and pyrocatechol afftec the shoulder of the slope in a way that is unique to these developers. I am not aware of any research with a similar finiding. If this research has been published somewhere please provide bibliographic information as to the source.

    Sandy
     
  18. Donald Miller

    Donald Miller Member

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    QUOTE (dnmilikan @ May 22 2003, 11:45 AM)
    This gives me a zone I density of .10 density above fb+fog.

    I have never understood why anyone cares about Zone I. It's density is not useful in any way since it's on the non-linear portion of the curve. Suppose you get a Zone I of .35 over f+b How do you adjust it? And even if you do find the "proper" .1 over f+b, it tells you nothing about how to adjust for the zones you do care about; namely zones III-VIII.


    In reply to the question about the reason for assigning a .10 density (over B+F) for a Zone 1 value. There is a very good reason, as I see it, it enables us to learn about the characteristics of our film. I posted an image the other day which I titled "Counterpoint". I will repost it for purposes of illustration. If I had assigned a .35 density for my Zone 1 negative value, I would have had the ice in the image at about Zone XVI. The highlights would have been lumped on the shoulder with very little if any separation. As it was I assigned my deepest values a Zone II exposure, the ice then fell on Zone XIII and I was able to bring the density into printable parameters by developing by inspection using ABC Pyro. The print did require additional sharp masking to gain better shadow separation.
     
  19. fhovie

    fhovie Subscriber

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    Hey Don:

    Do you have one of those fancy pin register masking tools or do you sweat throught it like I do, lining things up using a lightbox and tape?
    Frank
     
  20. lee

    lee Member

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