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Thread: Pyrocat Tests and Some Disappointment?

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  1. #1

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    Pyrocat Tests and Some Disappointment?

    Hello all - Been lurking a few months now (very educational!) but wanted to share some recent film testing and get some opinions on the results, apologies for my lengthy blather:

    I've just recently started processing my own film again after a 15 year hiatus, and instinctively reached for my old standby HC-110 to process 4x5 TMX. But to add interest and after reading many glowing reports on this forum I decided to give Pyrocat-HD a try. I've been really surprised (and a little disappointed?) by the results, and wanted some extra eyes to spot any issues in my process / results / expectations. Excuse the boring subject matter and somewhat flat scan, I scanned to retrieve all the information from the negative, putting the white and black points just beyond the end of the histogram:

    HC-110 (Dilution B @ 68F 7.5m, TMX EI 100) : http://gottanukesomethin.com/photo/d...ei100-7-5m.jpg
    PyrocatHD (1:1:100 @ 68F, 16m, TMX EI 50) : http://gottanukesomethin.com/photo/d...-1-100-16m.jpg
    PyrocatHD (1:1:100 @ 68F, 16m, TMX EI 100) : http://gottanukesomethin.com/photo/d...-1-100-16m.jpg

    Processing:
    All done single-sheet in homemade PVC tubes with ball valves as light-traps. I can see no fogging / streaking / scratching from this process.
    Agitate continuously for first minute, then 10 seconds / minute thereafter. Standard dilution indicator stop and kodafix.

    So all three negatives look fairly reasonable, nothing blown out or terribly underdeveloped, the 50 EI is preferable of the two Pyrocat negs I think, but my concern is the highlights: the HC-110 negative shows good seperation and local contrast in the top of the binder pages (which I placed in the neighborhood of Zone VIII), but the Pyrocat negatives seem to have flattened out and gotten a bit murky and undetailed. I guess I can see how this would be a pleasing effect in many situations, but the loss of local contrast seems a bit dicey to me and makes me nervous about Pyrocat for general use. Maybe I'm falling for magic bullet syndrome, but I was surprised to be overall happier with the HC-110 (in this admittedly non-real-world test).

    So, do these negatives look like I should expect for Pyrocat HD? Is there something flawed in my process or my testing, or should I accept my results and keep on with my nice cheap yellow cough syrup? Would another film show the PHD magic?

  2. #2
    Peter J. De Smidt's Avatar
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    Re: Pyrocat Tests and Some Disappointment?

    Is the goal to make prints traditionally or to scan?

    A quick response would be to try developing for a longer time with the pyrocat.
    "Nothing will ever be attempted, if all possible objections must be first overcome." -- Samuel Johnson
    www.peterdesmidt.com/blog

  3. #3
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    Re: Pyrocat Tests and Some Disappointment?

    You haven't mentioned how you metered the photos or printed/scanned them.

    All things being equal, wouldn't we expect to see roughly 1 f/stop difference in the high values, when comparing two images identically developed but exposed 1 stop differently ?

    For example: if they are all under-exposed and under-developed, and then corrected in scanning or in the image editor - then can we draw a reasonable conclusion ?

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    Re: Pyrocat Tests and Some Disappointment?

    Peter: Scanning as a final product, at least for the foreseeable future. Develop for a longer time with the same agitation? My instinct is that I would end up blocking the highlights even further, but I'm willing to accept being wrong about that...

    Ken: Metered the small gray square above the Ilford box as Zone V, Top of the binder fell around Zone VIII. EI 50 shot corrected back to reasonable values via the scanner. EI 100 shots were f11@1/2 sec, the EI 50 was f11@1 second. I am definitely willing to rescan later tonight to eliminate the correction as I'd love to feel definitive about these results... The EI 50 exposure was from my (perhaps mistaken?) impression that I would lose some film speed with the Pyro, so I decided to cover that base and over-expose one negative as a test. If that is a poor assumption (re: film speed loss) then we can compare just the two @ EI 100.
    Last edited by sgutterman; 22-Mar-2012 at 14:24. Reason: added response...

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    よろしくお願いします! Andrew O'Neill's Avatar
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    Re: Pyrocat Tests and Some Disappointment?

    sgutterman, how does the stain look?

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    Re: Pyrocat Tests and Some Disappointment?

    I'm no expert but I would want to make the comparison with the Grey Card adjusted to the same value in PS.

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    Re: Pyrocat Tests and Some Disappointment?

    Andrew: Noticeable sepia color, does not appear to be any non-image stain but this is coming from a voice of zero experience. Other than highlight detail I *think* the negatives look healthy.

    (And thanks to all replying I appreciate the input!)

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    Re: Pyrocat Tests and Some Disappointment?

    sgutterman,

    Since you gave the EI 100 sheets identical exposures, The differences in exposure can reasonably be attributed to the different developers, provided both sheets were developed to the same contrast, which It doesn't appear they were. The PCHD sheet looks a little more developed than the HC110 sheet. This small variation in development shouldn't have much effect on the film speed, but it does affect the rendition of the highlights. On my screen, the PCHD sheet looks better overall than the HC110 sheet, which seems to have a haze/fog over the image, but this could be attributed to the difference in contrast. If you want your PCHD developed film to look more like your HC110 film, try decreasing development of your PCHD film. On the other hand, if you like your HC110 film, why not stick with HC110?

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    よろしくお願いします! Andrew O'Neill's Avatar
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    Re: Pyrocat Tests and Some Disappointment?

    Try what Tony suggests. Match your gray card to its proper value in photoshop. Adjust your black/white points. All three images are a bit dark. Also, as a side note, if you are just scanning and working digitally, a thin negative scans best. Really thin.

  10. #10
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    Re: Pyrocat Tests and Some Disappointment?

    When judging film speed and development time:

    In the world of the wet darkroom (enlarging or contact printing) we can decrease the number of variables by using a standard printing paper and standard developer. We expose and develop for a standard time: just enough to print through the film base. This approach is popular in the Zone System.

    In the world of sensitometry, we further decrease the number of variables by getting rid of printing altogether: we use a transmission densitometer to measure film density directly. This is the method used by film manufacturers and experts in exposure and development. It's also the method used in BTZS. After all, film speed changes with development time. It's a moving target. Film doesn't have just 1 speed. That's why Minor White (Zone System) recommended that we increase or decrease exposure according to how we intend to contract or expand contrast via development.

    On the other hand, complexity is increased as soon as we we add a scanner and an image editor to the equation - and a monitor, printer, paper, etc.

    I suggest you have a look at this article on Pyrocat HD, paying particular attention to the way in which different films and development times are discussed. Don't read anything: just look at the charts. Page four is particularly revealing: it shows how the contrastiness of different films is affected by changes in development time, with just one developer. It's very easy to see how they differ.

    A few graphs and numbers can save us a lot of time and materials, and rescue us from the tangle of speculation, hearsay, and anecdotal evidence.

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