tri-x@400 in preceptol 1+3?

Discussion in 'B&W: Film, Paper, Chemistry' started by pierods, May 27, 2008.

  1. pierods

    pierods Member

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    How long for tri-x @400 iso in perceptol 1+3?

    I only found the time for iso 320 (15 min@20 C), but the roll is already shot at 400.

    Anybody knows?

    Thanks
     
  2. Michel Hardy-Vallée

    Michel Hardy-Vallée Membership Council Council

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    I think I used 17mins last time. Negs turned OK, but a simple metol developer like D-23 would give pretty much the same results for less processing time.
     
  3. pentaxuser

    pentaxuser Subscriber

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    The strange thing is Ilford doesn't give times for most 400 film in Perceptol but yet as we know from the second poster people have had success with Perceptol at box speed. It becomes even stranger when you look and see that for D3200, its top speed film, Perceptol is actually recommended by Ilford and at box speed. When I saw this information, my notion that Perceptol was a developer that reduced all fim speed by at least a 1/3rd stop and wasn't suitable for box speed development had to be re-examined. I have used Perceptol with D3200 at box speed and was pleasantly surprised at the neg and especially surprised at the relatively grain free print. Much better than I had previously achieved with ID11.

    Is there a good "chemistry" explanation which reconciles what appears to be a contradiction here?

    No direct help I know but it may be germane to the thread.

    pentaxuser
     
  4. jim appleyard

    jim appleyard Member

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    IIRC, most films show box speed when used with Perceptol/Microdol-X 1+3. I think it's because the sulfite content is so diluted that there isn't as much to eat away the silver in the film leaving more to catch the light; at least I think that's what Anchell & Troop are telling me.

    It's on page 70 of the "Film Developing Cookbook".

    It's also recommended that film be souped at 24C to shorten the times.
     
  5. tbm

    tbm Member

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    Perceptol is essentially a duplicate of Microdol-X, and I regularly use the latter developer diluted 1:3 for 17-18 minutes at 74-75 degrees with Delta 100 and Acros 100 and get outstanding negatives!
     
  6. fschifano

    fschifano Member

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    Yes, both Jim and Pentaxuser are on the money here. Perceptol is Ilford's functional equivalent of Kodak's Microdol-X, and I've used enough Microdol-X in my time to verify what they've written. At full strength, speed loss can be as much as a full stop and gain that "fine grain" effect. However, once you dilute to 1+3, the situation is reversed. The fine grain effect is lost, but full emulsion speed is achievable.

    Anyway, 320 is only 1/3 stop slower than 400, so I wouldn't worry too much about it. Extending development a minute or so over the recommended time might boost the shadows a bit, but only if there is some detail there to begin with.