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  1. #21

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    Quote Originally Posted by jdef
    Hi Sandy and Kirk.

    I've tried to double check my results with the information you've posted regarding Pyrocat HD, even though you use FP4+ and I use HP5+. The differences in activity appear to be dramatic enough to outweigh any differences in the filmstocks. For instance, in one of your posts you report that a 5:3:1:1:100 dilution of Pyrocat+ with FP4+ processed for 12min/72F with continuous agitation read with the Blue channel produced densities of:

    (snip, snip)

    Have you noticed a reduction in definition with Pyrocat+ compared to Pyrocat HD? The method of development is important for adjacency/edge effects, and the products of development can play an important role.

    Jay
    Jay,

    Yes, I am much too busy with others things right now to be doing any film testing, but I have dozens and dozens, if not hundreds of files of tests with many film/developer combinations that serve as reference that I can look at without actually doing any further testing.

    Your comparison of my results with FP4+ in Pyrocat-HD 5:3:1 with your results with HP5+ in 510 Pyro is not a good one for several reasons, but most importantly because in my test of Ilford FP4+ with the 5:3:1 dilution the film actually reached gamma infinity at a time of slightly more than seven minutes. In other words, no additional contrast was obtained after eight minutes of development so the twelve minute time mentioned is something of a canard.

    As of this point I have not done any serious comparison between Pyrocat-HD and Pyrocat+ to see if there is any difference in sharpness. However, what I can say for sure is that there is for sure an increase in sharpness of Pyrocat-HD negatives processes with minimal and semi-stand agitation in comparison to those processed with rotary (constant) agitation. Which is why I stated earlier that the method of processing with this class of developer is probably much more important than the formula itself if maximum apparent sharpness is the objective.

    You are of course right in that the ultimate quality of a high definition developer is that it produces maximum apparent sharpness.

    BTW, I am pleased to see the reduction in the amount of phenidone in your 510 Pyro compared to some of your previous developers, since having too much of this reducer causes more loss of sharpness (because of the tremendous regenerative quality of phenidone) than a mild excess of one of the other reducers. At some level of agitation I consider it highly likely that the reduction in phenidone will have a positive effect on apparent sharpness.



    Sandy
    Last edited by sanking; 05-13-2005 at 04:25 PM. Click to view previous post history.

  2. #22

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    Quote Originally Posted by jdef
    It's hard to tell from the curves, but the Dmax values for the developers are:

    510-Pyro 1:100 2.07

    Pyrocat HD 2:2:100 2.72

    Hypercat 1:1:100 3.02


    Jay

    Jay,

    My first impression of the comparison data did not suggest the magnitude of difference in activity between the 510-Pyro and Pyrocat-HD that you show above. I wonder if there is not some type of anomaly in your graphing program? For one thing, the axis for Pyrocat-HD seems shifted up (suggesting over exposure) about one full stop relative to the 510-Pyro axis. This would explain, at least in part, the higher maximum density of Pyrocat-HD. I think that if you run these tests again, adjusting exposure, you will find that the energy level of 510-Pyro and Pyrocat-HD is much closer than your initial results indicate.

    Sandy

  3. #23

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    Quote Originally Posted by jdef
    Sandy,

    I'm using a sensitometer for all of my exposures, which is very accurate and repeatable. The upward shift you refer to is due to the greater fog levels produced by Pyrocat HD compared to the other developers. The B+F values for the curves are:

    510-Pyro .26
    Pyrocat HD .46
    Hypercat .29

    Jay
    Sorry Jay, but you are simply wrong and there are no ifs, ands and buts about it. Something is very much off at your place. Pyrocat-HD produces very low B+F levels, as low as developers such as D76 and Xtol. If you are getting B+F of .46 in blue channel mode with HP5 developed in Pyrocat-HD, at the CI levels in question, then something is wrong with your procedures, either with the way you mixed Pyrocat-HD, or or with your sensitometer, or with some other aspect of your work.

    Sandy

  4. #24

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    Quote Originally Posted by jdef
    Nothing is impossible. I'll make a new batch of Pyrocat HD and try again.

    Jay
    Jay,

    That would be in order.

    Just for the record, one of the main reasons that Pyrocat-HD became very popular with many alternative printers is because it gives very low B+F levels, compared to other pyro developers, with UV sensitve processes, even with development to very high CI. Blue channel B+F levels are *even* lower, usually on a par with non-staining developers.

    No way Pyrocat-HD should give B+F levels of the magnitude you suggest. If it did, there would be very few people using it.

    Sandy
    Last edited by sanking; 05-14-2005 at 12:28 AM. Click to view previous post history.

  5. #25

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    Quote Originally Posted by jdef
    Sandy,


    I think I must have left the potassium bromide out of the first batch. Pyrocat HD 2:2:100 is still much more active than 510-Pyro, but the fog levels are down near the other developers now. Thank you for your help in sorting this out.

    Jay
    The B+F still seems higher than it should be. How are you measuring the potassium bromide? If you are mixing the Pyrocat-HD stock solution in small amount the accuracy of your weighing is a very important issue. It is pretty difficult to accurately measure 0.2 g for the 100ml stock.

    A better way would be to mix up a stock solution of bromide, say abourt 10%, and then add the amount to the Stock A solution.

    I mention this because the difference between 1.5 g and 2.5 g in a liter of Stock Solution A makes a very big difference in B+F and EFS.

    Sandy

  6. #26
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    Jay, I'm getting ready to mix a little of this brew. Measuring an 1/8 gram on phenidone is a bit of a bugger. I might get close on my old analog balance. Is there a better way? I know sometimes one makes a percent solution with phen and alcohol, but does bringing alcohol into the mix mess it up? Maybe a percent solution of phenidone in TEA?

    Comments please.
    Watch for Loose Gravel

  7. #27
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    Jdef,

    Wondered why you were carrying 3 places.

    1/4 gram I can measure. Appreciate the update.
    Watch for Loose Gravel

  8. #28

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    Jay,
    About the 1:250 dilution can you provide any starting point times for Delta 100 or Panf F.
    Also what agitation protocol would you recommend? Also is there any any image enhancement with the higher dilution?
    Michael

  9. #29
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    Quote Originally Posted by sanking
    The B+F still seems higher than it should be. How are you measuring the potassium bromide? If you are mixing the Pyrocat-HD stock solution in small amount the accuracy of your weighing is a very important issue. It is pretty difficult to accurately measure 0.2 g for the 100ml stock.

    A better way would be to mix up a stock solution of bromide, say abourt 10%, and then add the amount to the Stock A solution.

    I mention this because the difference between 1.5 g and 2.5 g in a liter of Stock Solution A makes a very big difference in B+F and EFS.

    Sandy
    I wonder if you remembered that Jay is using 35 mm HP5+ and that it has a base density higher than most sheet films that have antihalation dyes. In order to be on the same page, perhaps Jay would measure the base density of an unexposed, fixed and washed piece of the film he is testing?
    Gadget Gainer

  10. #30

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    Quote Originally Posted by jdef
    At Pat's suggestion, I fixed and washed a strip of undeveloped 35mm HP5+ as I would in my normal processing, and when dry, the density measured .18, which seems about right. I also did some field testing of J&C Pro 100 and HP5+ and developed the films in Hypercat, 510-Pyro, Pyrocat HD, PMK, and Xtol. It is clear to me now that I was right when I stated that 510-Pyro is more active than Pyrocat HD. It is in fact the most active of the developers I tested, based on VC print contrast, and along with Hypercat, compared favorably to the other developers in every category of my tests.


    Jay
    So why the contradiction?

    Earlier you wrote.

    "I did a direct comparison of Pyrocat HD 2:2:100 vs 510-Pyro 1:100, both developed for 10min/70F with continuous agitation, and it seems you're right; according to my test, Pyrocat HD 2:2:100 is MUCH more active than 510-Pyro 1:100. I'll attach both curves. I retract my statement regarding the relative levels of activity of the two developers, and apologize for any confusion it might have caused."

    In the test above you state that Pyrocat is significantly more active than 510-Pyro. In fact, you repeated the test with a new solution of developer, to which you added bromide, after I pointed out to you that the B+F of the Pyrocat-HD negative was much too high. And after that second test you wrote.

    “I think I must have left the potassium bromide out of the first batch. Pyrocat HD 2:2:100 is still much more active than 510-Pyro, but the fog levels are down near the other developers now.”

    But now you say that is not the case!

    Based on the contradictory statements one must conclude that you have made mistakes, either in testing or in reporting, and you need to straighten this out. I don’t really care which of these developers is more active, but I do care about consistency in testing, in getting the facts right, and in reporting the right facts.

    Sandy
    Last edited by sanking; 05-20-2005 at 10:08 AM. Click to view previous post history.

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