Hello Shannon, Taking into account all uncertainity concerning reciprocity failure and relating it to the problems you're facing, are you sure these problems aren't on the exposure side of the situation ? Rather than struggling so much with development, haven't you thought trying to alter your exposure times ? Does this make any sense ?
Ricardo. ----- Original Message ----- From: "Shannon Stoney" <[email protected]> To: <pinhole-discussion@p at ???????> Sent: Wednesday, July 17, 2002 2:29 PM Subject: [pinhole-discussion] measuring density range > Chris wrote: > > > While waiting for an appointment I pulled out my alt books for a little > > reading. In Christopher James's book page 136 he says that a range of > > 1.8 is needed for Mike Ware's New Cyanotype formula. He say's "Mike > > advises extending from base+fog (0.2) to a D-maz of 2.0 or more. This is > > achieved by "overdeveloping" the negative to the extent of 70% to 80%". > > > > Your development time is already beyond 100% but you only have a density > > of 1.36. I would think this would tell me that there is something else > > wrong. Its good to know how they are measuring their density range. I > > didn't know if it was base+fog to D-max or shadow detail to highlight > > detail. Looks like from this book its the former. > > Yes, I had never thought of measuring it that way. I always measure it from > shadow density to highlight density, following Dick Arendtz. > > > > > Now that I know this I wonder if your following zone system measurement > > procedures and only reading shadows with detail and highlights with > > details. If that's the case then you might have perfect negatives > > already since it seems that alternative workers read everything not just > > the details ;-) > > In the past my perfect negatives for cyanotype, made with a lens camera, had > a density range of about 1.6. This was the difference between the > "important" shadow areas and the highlights. So I have maintained that way > of working. I guess it doesn't matter which way you measure the difference, > as long as you know what works for you and you are consistent. What works > for me is, a difference of 1.6 between the shadows and the highlights. I > ignore the base+fog measurement. However it seems that it might be > important to know what it is for different films, as a dense base+fog might > explain why HP5+ for example is hard to get thin enough in the shadows. > > > --shannon > > > -- > > -- > > Chris Peregoy | http://www.gl.umbc.edu/~peregoy | http://imda.umbc.edu/ > > > > > > _______________________________________________ > > Post to the list as PLAIN TEXT only - no HTML > > Pinhole-Discussion mailing list > > Pinhole-Discussion@p at ??????? > > unsubscribe or change your account at > > http://www.???????/discussion/ > > _______________________________________________ > Post to the list as PLAIN TEXT only - no HTML > Pinhole-Discussion mailing list > Pinhole-Discussion@p at ??????? > unsubscribe or change your account at > http://www.???????/discussion/ >
