Re: Pd with dichromate contrast control
Thanks, Sandy. That's a starting point, at least. I'll play around with it and see what I can come up with. Camden Hardy camden[at]hardyphotography[dot]net http://www.hardyphotography.net On Thu, December 14, 2006 12:01 pm, Sandy King wrote: > Hi Camden, > > No, I could not tell you how much to add, but it would be a very > small amount. If I were gong to test this I would try a 1% AD > solution and see what would happen with 6-6-1 rate (6 drops FO + 6 > drops PC + 1 drop of the 1% AD solution. But I could be way off on > this. I know that adding one drop of a 5% solution of 2ml of combined > FO+PC has a very significant impact on contrast. > > Sandy > > > > > > At 11:08 AM -0700 12/14/06, Camden Hardy wrote: >>Sandy, >> >>Thanks for the information; that was just what I was wondering about. >>I've got a surplus of ammonium dichromate that I've been looking to use >>up. >> >>Just out of curiosity, do you have any estimates as to what ratio of 5% >>dichromate I would have to add to my sensitizer (instead of the >> developer) >>to get roughly a 2s mix? >> >>Camden Hardy >> >>camden[at]hardyphotography[dot]net >>http://www.hardyphotography.net >> >> >> >>On Thu, December 14, 2006 10:58 am, Sandy King wrote: >>> Camden, >>> >>> Any of the dichromates can be used, and when used at the same >>> percentage solution will give similar results. I don't recommend >>> sodium dichromate for most applications because of its deliquescence, >>> and its greater solubility offers no advantage in this application so >>> far as I can see. >>> >>> Sandy >>> >>> >>> >>> At 10:50 AM -0700 12/14/06, Camden Hardy wrote: >>>>Thanks for pointing that out, Mark; somehow I missed it entirely. Too >>>>obvious, I guess. :) >>>> >>>>However, the book only talks about sodium dichromate. I've heard >>>>potassium dichromate mentioned here before (was that you Sandy?). >>>> >>>>Am I just imagining the use of ammonium dichromate? I thought someone >>>>mentioned it in the Ware/Malde POP discussion (the search function of >>>> the >>>>recent archives is down at the moment, so I can't verify it). >>>> >>>> >>>>Camden Hardy >>>> >>>>camden[at]hardyphotography[dot]net >>>>http://www.hardyphotography.net >>>> >>>> >>>> >>>>On Thu, December 14, 2006 10:35 am, Ender100@aol.com wrote: >>>>> Camden, >>>>> >>>>> Dick has such a conversion chart in the second edition of his >>>>> book. >>>>> >>>>> Best Wishes, >>>>> Mark Nelson >>>>> >>>>> Precision Digital Negatives - The System >>>>> PDNPrint Forum at Yahoo Groups >>>>> www.MarkINelsonPhoto.com >>>>> >>>>> >>>>> In a message dated 12/14/06 11:22:46 AM, >>>>> camden@hardyphotography.net >>>>> writes: >>>>> >>>>> >>>>>> I've been using the Dick Arentz method of pd contrast control with >>>>>> various >>>>>> concentrations of the Na2 solution. I'd like to try printing pure >>>>>> palladium with ammonium dichromate for contrast control, as I've >>>>>> heard >>>>>> someone mention in the past. >>>>>> >>>>>> So my question is, how does one method translate to the other? >>>>>> What >>>>>> kinds >>>>>> of quantities/dilutions of am. dichromate would I need to use to >>>>>> get >>>>>> comparable contrast results to Arentz's 1s/2s/3s solutions? I >>>>>> realize >>>>>> this is an apples/oranges question before asking it, but I'm >>>>>> having >>>>>> trouble finding a better analogy. :) >>>>>> >>>>>> >>>>>> Thanks, >>>>>> Camden Hardy >>>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>> >>> > >
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