Re: Pd with dichromate contrast control
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 >>>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> > >
|