Film Speed/Developing Confusion

Discussion in 'B&W: Film, Paper, Chemistry' started by 2Ldude, Aug 31, 2005.

  1. 2Ldude

    2Ldude Member

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    Hello everyone,

    In reading books, threads, different web sites I have the following questions regarding establishing EI for the various films and camera's I have.

    1) How do you determe film speed since it is based on being able to develop film "in your normal way".

    2) I am transitioning from PMK, normal agitation, to Pyrocat-HD with agitation cycles at 3 minute intervals.

    3) Films I am testing will be:
    FP4 - 35mm, 120 (both in daylight tanks)
    FP4 - 4x5 in dip and dunk tanks
    Delta 3200 - 120 in daylight tanks
    TMY400 - 4x5, 8x10 in dip and dunk tanks, slosh trays
    PL100 - 8x10 in slosh trays

    I guess the biggest question I have is:without a "normal development time" how would you determine personal EI ?? I ball park development time in my understanding would give me the ability to read density (dont have densitometer) but wouldnt this density change if I also changed the development time also which to me would mean I would have to start all over??

    I have read about using the Stouffer Step Wedge too. My question with that is how do they determine the density's on it to compare the density's of my film with ?? Wouldnt different film have different thicknesses which would effect the density's I would compare to on my film??

    And lastly, once I have developed the film and determined some kind of density for film speed how would I determine if I needed to develop for longer or shorter times to get the optimum density or would I change film speed.

    I have read through the books The Negative by A.A, BTZS by Phil Davis and countless websites and they all (unless I missed something which is possible since my wife says I am blind) that film speed test, personal EI is conducted using your normal development techniques. Since I am changing developer and agitation which do I do first?? Use current film speed (personal EI) and get a development time and agitation cycle first, then re-do film speed test.


    Thanks for all the advice in advance.
     
  2. Paul Howell

    Paul Howell Member

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    There are several ways to determine your true film speed, from a similar post last week it seems that the View Camera Store will test your negatives and give you recommend times for your film and developer. You can also test without a desitometer by first testing your paper speed and developer then testing your film fist to determine your EI for shadow detail, then development times for highlight details. Post me if you want further details on self testing. I have not used the service provided by the View Camera Store but it seems like a real time saver.
     
  3. seadrive

    seadrive Member

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    The theory is that your EI is based on the low-density areas of the scene/neg, which are less dependent on development time than the high values (expose for the shadows, develop for the high values), so your precise development time shouldn't be an issue. Just use the manufacturer's recommended time for the EI test.

    Once you have your EI, you can then proceed to the development time test.

    Have fun! :smile:
     
  4. bobbysandstrom

    bobbysandstrom Member

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    I don't want to seem like a sales person for the BTZS, however, if you really want to know your materials, this is the most expeditious way to do so. As for Pyro, there are complications but I think Sandy King has found a way around them...

    With BTZS, you first calibrate your enlarger exposure by an appropriate setup that yields a fim speed of 100 from delta 100 developed with the tubes in d76 or xtol(don't have times/temps/dillutions in front of me) and plots the curves using a personal reference speed point in the plotter software. Once your exposure is calibrated, you can then adjust your light source via aperature or enlarger height so that a meter reading off the baseboard will yield the box speed of whichever other film you wish to test. So, for example, if you have a reading of EV4 for delta 100 you would adjust your enlarger to a reading of EV2 for a 400 speed film. Next you plot the curves of the tested films against the same PRSP in plotter. You will then know your true film speeds for various subject brightness ranges.

    OR

    Have View Camera Store send you the test negs using your film of choice, process them your normal way and return them to the VCS. They will in turn send you all of the data you need to get the perfect exposure in any light condition your film/dev combo can handle.

    hope this helps

    bob
     
  5. Donald Miller

    Donald Miller Member

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    Another factor that is a part of BTZS is that EI is not fixed but instead changes with changing SBR and hence development.
     
  6. 2Ldude

    2Ldude Member

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    Without the use of a densitometer (haved searched under every rock and sagebrush in the surrounding area) I dont think I can follow the theories listed in the BTZS although I would love to. I guess I am stuck with the original zone system techniques.

    Paul, you mentioned testing paper first and then adjusting EI to fit into that paper speed range. Would this mean that I would have to do a film test for each paper that I will be using??
     
  7. resummerfield

    resummerfield Subscriber

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    Try to find the Fred Picker book "Zone 6 Workshop". He has a fairly simple explanation of film testing, based on the final print. And he does not use a densitometer.
     
  8. Ronald Moravec

    Ronald Moravec Member

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    Same way I have alwas done it and other photogs for the past century. Pick a subject with detailed black and detailed whites. Expose for box normal, plus 1/2 stop, plus 1 full stop. Develope and print the least exposed frame that shows required shadow detail. Print the blacks properly and evaluate the whites ,adjusting the white density with development time as necessary. Small changes in time will not significantly change the shadow detail.
     
  9. Paul Howell

    Paul Howell Member

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    Yes, I was taught this approach my one of my old NCOIC of the Air Force photo lab I was first assigned to in 1970. He used a Kodak print scale as a 10 step wedge, put a clear negative in the enlarger, stop down your lens to F 8 or F11 and expose your paper that has been cut down to fit the Kodak scale in 2 second intervals and then develop in your standard print developer at your standard time until you get a print that has all 10 gray scales which will approximate the 10 Zones, with the middle wedge at zone 5. If you use VC filter filter for grade 2 or 3. So when you test for film you always print at the same F/Stop and time that gave a full range test print. So you do need to test for each paper.
     
  10. 2Ldude

    2Ldude Member

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    Thanks for all the help guys. I have alot better understanding now and a direction to go. I also went to home depot and found enough stuff to make the poor man's densitometer using the diagram in BTZS. What it didnt say was whether the reversed lens was stopped down or wide open, focused at infinity.... I guess I will have to trial and error that part.

    Paul, I also dug up a print projection scale for my enlarger that I will use for the paper test along with my negatives. thanks for the advice.
     
  11. 2Ldude

    2Ldude Member

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    One last thing and it probably doesnt apply to this forum but does anyone out there know where to get a step ring that goes from around 28-30mm (spot meter) to 49mm (lense) male threads on both ends. I have found some but not that small on the spot meter end. Otherwise I am down to fashioning plastic pipe to fit over the end of the spot meter.
     
  12. engbobs

    engbobs Member

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    Without the proper steps determining film speed can be an elusive item. I have mostly used the Zone VI Fred Picker method and found it to be the easist and most certain. What I do is expose the film of choice to a white card and with a spot meter determine the exposure for Zone I at various assumed film speed ratings. To keep track of the work I put notes on the white card indicating the film, developer to be used and the assumed film speed for each frame exposed. After developing the film with the developer I plan to use consistently I check to find which frame has a density of 0.1 above film base plus fog using a densitometer. If you dont have a densitomer perhaps the local photo lab you use would perform the readings. When the film speed is determined for the combination of film, camera, lens, spot meter and development scheme, I then proceed to expose a new set of films to determine Zone densities from Zone I to Zone X for various development times for the standard developer I plan to use. With this data I can plot the Zone versus density curves for various development times and now I have the data I need to establish camera exposure times to create the negative contrast range I am seeking for a particular subject. There is a bit of front end effort in this but well worth it in the final results that have a reasonable preditability.
     
  13. esanford

    esanford Member

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    Fred Picker's method is absolutely fool proof for determining film speed as outlined above. It is also pointed out in Fred's book "the Zone VI workshop" which is always available on ebay for less than $10.00. If you don't have a dentsitometer, you can mail your films to Richard Ritter who used to work for Fred, and he will provide test results for $7.50. Here is his address below along with his website:

    For testing send the developed film along with a check or money order for $7.50 to;
    Richard Ritter
    POB 401
    Townshend, VT 05353-0401
    http://www.lg4mat.net/

    I sent my original tests to Fred 15 years ago before he passed away. Also, I was going to send him 5 or 6 films to test. He said "son, you are hopelessly lost if you need to test that many films"... "stick to one film, one developer and one paper and you may eventually find out what the hell you are doing".....:smile: I took that sage advice, and I am glad that I did...
     
  14. dancqu

    dancqu Member

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    With changes in development the EI will change some
    what. A shift from N-2 to N+2 development will likely
    at least double if not triple the EI. The SBR, in it's
    self, has nothing to do with the EI. Dan
     
  15. bobbysandstrom

    bobbysandstrom Member

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    As I've stated in previous threads, call the View Camera Store and talk to Fred. For the effort of developing the 5 sheets of film (he sends you) at 4, 5:30, 8, 11, and 16 minutes, and a little bit of money ( I think $40.00) you will receive back ALL OF THE DATA you need to make as perfect a neg possible in just about any light condition. (You don't need a densitometer) That includes the various film speeds for your plus and minus developments. And, this will be tailored to fit your printing paper like a glove! It really is that easy.

    I get no compensation for promoting this, I just think it's a shame that more people aren't aware of it!

    Good Luck!

    Bob
     
  16. Donald Miller

    Donald Miller Member

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    While I would agree with you on the face of what you said, I would go on to say that you did not follow what I said to it's logical outcome.

    My point being, and I think that you will agree, that SBR determines development and development affects EI...so SBR does effect EI. Agreed?

    Additionally BTZS does not have N+2 or N-2 development designations. It would appear that you are intermingling BTZS and Zone system practice.
     
  17. dancqu

    dancqu Member

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    [QUOTES=Donald Miller]
    "While I would agree with you on the face of what you said,
    I would go on to say that you did not follow what I said to
    it's logical outcome."

    "My point being, and I think that you will agree, that SBR
    determines development and development affects EI...so
    SBR does effect EI. Agreed?"

    I don't agree save for the special case where one wills
    that the SBR dictate development. That special case is
    one where there exists only one paper of one grade and
    A specific chemistry to be used. That's the fit the film
    to the paper way.

    I shoot roll film and fit the paper to the film. The two
    most used methods are VC paper and Graded papers. A.
    Adams used a modified two part Ansco 130 developer.
    My own tests with Beer's two part VC developer
    look very good.

    "Additionally BTZS does not have N+2 or N-2 development
    designations. It would appear that you are intermingling
    BTZS and Zone system practice."

    Well I'm not the only one intermingling. Reading a D-Max
    Newsletter I see that Phil Davis equates his Beyond with the
    Zone System. "... Diafine is not a practical developer for
    BTZS ( or Zone System )..." . I think Ansel and the f64
    group would understand. Dan
     
  18. Peter Schrager

    Peter Schrager Subscriber

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    Zone-VI

    Just to throw a little humor into the mix: note from Fred Picker on my densitometer test I sent him once; "son;these are all over the barn" I still laugh to this day! And he wasn't wrong either.
    Best, Peter Schrager
     
  19. Donald Miller

    Donald Miller Member

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    You apparently have a peliminary knowledge of both the Zone System and BTZS. Your response indicates an elitist attitude when no apparent basis for this attitude seems to exist.
     
  20. sanking

    sanking Member

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    But IMHO, having the SBR or N situation dictate development is the common case, not a "special case," for most photographers who have established good control of their process. The normal case is to expose and develop for a mid-range contrast of the process, say for a #2 graded paper or a #2 VC filter, and then adjust for more or less contrast in the negative by applying process controls. That is basically what people who shoot 35mm and roll film do, even if their methodology is no more sophisticated than following time/temperature charts for a specific film/developer combination.

    I agree about the mingling of SBR and N terms when talking about BTZS. Phil Davis does it, and I do it also. In fact, the Winplotter program of Davis will allow one to calcualte exposure and development based on either SBR or N values. Of coure, both are simply linked to required negative DR and print ES by average gradient.

    Sandy
     
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