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  1. Replies
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    Re: Zone System Negative Design needs an Update

    Generally speaking The Zone System is fairly superfluous, but the article is quite flawed.
  2. Re: TF-4 vs. TF-5 for FP4+ Developed in Pyrocat HD?

    There is no reason to prefer TF-4 over TF-5.
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    Re: t-max 100 alternative

    +1

    TMX 100 and Delta 100 have nearly identical characteristic curves in a variety of general purpose developers. TMX is a little finer grained (doesn't matter for LF). The two films have different...
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    Re: flashing paper

    Thom,

    Yes, exposing the paper to non-image forming light (ie flashing) reduces contrast. What you want to do in your case is give the paper the maximum exposure which does not produce any visible...
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    Re: When did selenium toning become popular?

    Anecdotally I think much of its popularity (and the widespread adoption of it as a de facto standard) has to do with Ansel.
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    Re: Hp5 vs TMY400

    Nice try, but again, totally incorrect.
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    Re: Hp5 vs TMY400

    It's always interesting to see how many incorrect things Drew can fit into each post.
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    Re: safe haven for tiny formats

    Montreal

    Ilford MG Classic/Dektol

    Apologies for the poor scan quality.


    174840
  9. Re: Ilford - new reciprocity failure compensation factors

    This describes most of the photography I do, which is under extreme contrast, low light conditions. It used to be complicated but after I learnt about exposure theory etc. I was able to simplify my...
  10. Re: Ilford - new reciprocity failure compensation factors

    I think the Zone System is fine for that. Things can be simplified though.
  11. Re: Ilford - new reciprocity failure compensation factors

    Underlying the ISO method is the Delta-X fractional gradient estimation. Delta-X tells us that speed doesn't decrease as much as the Zone System says it does, when contrast is reduced, and that speed...
  12. Re: Ilford - new reciprocity failure compensation factors

    Doremus,

    It's just place and fall. I think we're saying the same thing but my wording was probably unclear. If you meter something and place it on Zone V, something else in the scene falls on Zone...
  13. Re: Ilford - new reciprocity failure compensation factors

    David,

    I'm not sure I completely understand the question, but I don't think your second paragraph is correct. Assume you set your meter to the film's ISO speed. Further assume there is no flare....
  14. Re: Ilford - new reciprocity failure compensation factors

    1) Look up the P factor for the film you are using in the Ilford table

    2) Whatever your exposure time is (in seconds), put that number to the power of the P factor (the P factor is the exponent),...
  15. Re: Ilford - new reciprocity failure compensation factors

    ISO speed point is the reference point, and the t-factors are based on the loss of effective speed relative to the ISO speed point.

    Effective speed is based on finding the exposure that produces...
  16. Re: Ilford - new reciprocity failure compensation factors

    Pere,

    Ilford used a fixed density criterion (0.1 above Fb+fog) to determine these t-factors. As you know, the speed point under ISO conditions is the exposure Hm where density is 0.1 above Fb+fog....
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    Re: Bergger Pancro 400 in sheets

    Paul,

    When processed in general purpose developers the Delta 100 characteristic curve is virtually identical to that of TMX. Attached is an example comparison of the two films developed in XTOL....
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    Re: I need FIX Hardner: ALUM?

    The other ingredient in the Tetenal product is acetic acid. This is because aluminium sulfate requires an acidic environment in which to work as a hardener - which is why you add it to an acidic stop...
  19. Re: Ilford Galerie Fiber dev'd w/ Ansco 130, Neutol WA, or Dektol, thoughts?

    Flashing grade 2 can help quite a bit. It can be a very useful control with graded papers.
  20. Replies
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    Poll: Re: New poll -- presoaking

    Perhaps, but as I believe you've noted before, ask 10 photographers... :)

    Anyhow, I presoak if I'm tray shuffling sheets (obviously). ~2 minutes in tap water, same temp as the rest of the process...
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    Re: Divided D-23 Question

    Alan, the control for contrast in your specific scenario (development takes place in both baths) is development time in bath A. Varying the type or concentration of the alkali in bath B will not...
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    Re: How To Understand Densitometer Readings

    The metered exposure is 1 log H (3 1/3 stops) to the right of Hm. Point n is 1 stop higher.
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    Re: How To Understand Densitometer Readings

    Pere - point n is not the metered exposure and is not Zone V.
  24. Re: Development times? FP4+, Shot at ISO 80, Rodinal, Continuous Agitation

    The assumptions include continuous agitation in all scenarios since that is what OP is doing (see post #14). Ilford recommends reducing all development times by ~15% to account for continuous...
  25. Re: Development times? FP4+, Shot at ISO 80, Rodinal, Continuous Agitation

    I'd want the same contrast (having shot at 80) as if I had shot at 125. Changing the development time changes contrast (reducing development time reduces contrast, increasing development time...
  26. Re: Development times? FP4+, Shot at ISO 80, Rodinal, Continuous Agitation

    All you did was meter at 2/3 stop below ISO speed. Changing the development time changes the contrast index. Is that what you want to do? If so, why?
  27. Re: Development times? FP4+, Shot at ISO 80, Rodinal, Continuous Agitation

    Paul - just to simplify matters a little, whether you shot the film with your meter set to 125 or 80 is of little consequence where development time is concerned. If you have a somewhat reliable time...
  28. Re: Contact printing: Practicing with RC paper, making final print with Fiber

    You will still need to adjust base exposure times (as well as other manipulations). For the base exposure adjustment, you could use the papers' ISO speeds (Ilford, for example, gives them) as a very...
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    Re: How To Understand Densitometer Readings

    Actually Zone III would be much lower than 0.9, closer to 0.4 depending on EI and contrast index.

    Zone I is typically targeted at ~0.1 above film base + fog.

    Keep in mind a densitometer reading...
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    Re: How To Understand Densitometer Readings

    Ian - you cannot do much better than this:

    https://www.kodak.com/uploadedfiles/motion/US_plugins_acrobat_en_motion_education_sensitometry_workbook.pdf

    It is an excellent, easy to follow...
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    Re: Developer Speed And ISO Question For 4x5

    The three developers you listed (and most general purpose developers) will give you essentially the film's ISO speed within a small fraction of a stop. XTOL will yield very slightly higher speed than...
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    Re: How many of you are self-taught (in LF)?

    You can definitely learn LF camera work and darkroom work on your own. Most of it will come down to learning a few basics, a lot of practice, and solving specific problems along the way. It would...
  33. Ilford - new reciprocity failure compensation factors

    As you may have noticed, the reciprocity failure compensation graphs in Ilford's film literature are generic. A few years ago I had a discussion with Harman tech service about how frankly lousy...
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    Re: Help Reading A Negative Please

    It depends on how you define speed. EI can change depending on how you choose to determine/measure it (Zone System for example), but film speed actually changes much less than people think with...
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    Re: Exposing at non-box ISOs: Why?

    Paul,

    Without getting into too much theory, to address the first question, this usually has to do with Zone System (and similar) test methods, which target a speed point 2/3 stop slower than the...
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    Re: Alkali vs Acid Fixers

    First, forget the Darkroom Cookbook for now. Use that book as a formula reference (the historical formulae are well edited in the 3rd and 4th editions), but the rest of it contains some bad...
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    Re: Alkali vs Acid Fixers

    Be careful what you read. What's written in the linked page ranges from true, to partially true, to it depends, to not true.

    Neutral/alkaline fixers can have a few benefits vs equivalent acidic...
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    Re: Question about testing for film speed...

    Unless one is using a particular process which results in a speed loss, the original Zone System EI test is indeed factually superfluous. However to answer Christopher's specific question, shooting a...
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    Re: Achieving adequate DOF in 8x10

    Remember when comparing formats, DoF is also a function of the enlargement factor, since the required CoC for a negative is a function of how much it must be enlarged.
  40. Re: Help me interpert my film developing test results

    A few comments:

    1. 1.15-1.35 above FB+fog is for Zone VIII exposure, not Zone V

    2. Test methodology needs to be revisited because the bottom of the curve looks very strange. There should be...
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