It was not my intent to imply that negative development helped achieve grade 5 but rather to make the point that it is easier to work with a properly developed negative instead of depending on filtration to get a good print. With a properly developed negative I can get a good print without using any filtration. This permits shorter exposure times. -----Original Message----- From: pure-silver-bounce@xxxxxxxxxxxxx [mailto:pure-silver-bounce@xxxxxxxxxxxxx] On Behalf Of DarkroomMagic Sent: Thursday, January 13, 2005 6:05 PM To: PureSilverNew Subject: [pure-silver] Re: New color head "discoveries" Hang on a second! Yes, it is true, you can get a true grade 5 from color heads on many papers. But, negative development has nothing to do with that. Paper contrast is measured as a log exposure range of the paper. This is independent of the negative, and consequently, not related to negative development. Regards Ralph W. Lambrecht On 1/13/05 11:46 PM, "Rob Champagne" <app@xxxxxxxxxxxxxxxxxxxxxx> wrote: > I think we agree on this. My point was merely to dispell the myth that > it is not possible to get a true G5 with dichroic filtration and that > with suitable neg development it is possible. Having done this if you > then use an ilford MG filter G5 the resulting print contrast would be > G5+ > > robc > > At 13/01/2005 14:01 -0800, you wrote: > >> ----- Original Message ----- >> From: "Rob Champagne" <app@xxxxxxxxxxxxxxxxxxxxxx> >> To: <pure-silver@xxxxxxxxxxxxx> >> Sent: Thursday, January 13, 2005 9:56 AM >> Subject: [pure-silver] Re: New color head "discoveries" >> >> >>> big snip >>> >>>> The filters of a color head will not give you the full range of >>>> contrast available from VC paper with the use of dedicated filters. >>>> They should give you a couple contrast grades on either side of >>>> "normal" but filters should be used >>>> to obtain the maximum and minimum contrast values. >>> >>> big snip >>> >>>> --- >>>> Richard Knoppow >>> >>> I wonder whether my observation is true for other dichroic filter >>> head enlargers. The Ilford Y+M figures for grade 2 on my Durst >>> CLS501 head enlarger give approx an ISO grade 1 result on paper. >>> It occurs to me that because dichroic filtration does not >>> seem to give as much contrast as filter sets, and because >>> most new enlargers have dichroic heads, that Ilford, and >>> maybe other manufacturers, use this to its advantage in >>> terms of film speed. >>> To get a true ISO grade 2 using ilfords G2 Y+M figures for >>> my enlarger I have to give the negative more development >>> which in turn gives allows a faster film speed. >>> So what I'm speculating here is that modern film speeds >>> may be tailored by the manufacturers to suit printing on >>> dichroic heads with Y+M filtration. >>> It should be noted that by using increased development of >>> the negative the overall contrast obtainable from a >>> dichroic is not far short of a true G5 and if you take neg >>> development far enough then a true G5 is obtainable from a >>> dichroic head. >>> >>> It all depends on what you are tailoring your development to. Do it >>> to 0 filtration and your negs will be too soft for G5 on dichroic >>> settings. Do it to G2 Y+M settings of your dichroic head and you >>> will get faster film speed and availability of higher contrast in >>> your print. >>> >> What are the other conditions of the comparison? Are the filters >> being used in the same enlarger or a different enlarger? What I am >> trying to get at is that if the filters are being used in a condenser >> enlarger the difference in contrast will be due to that. Color heads >> are very diffuse sources. The type of light makes little or no >> difference to the dye images of color but will change the silver >> image film about one paper grade. >> If the settings of the color head re right for the paper >> it should exactly duplicate the contrast of a filter for >> that grade. The limitation of the color head is that it may >> not be able to reach the extremes of the contrast range of >> the paper. This is normally of little consequence. >> Since ISO film speed is measured at a fixed contrast >> (about right for diffusion printing) a change in contrast >> will result in a change of effective speed. changing the >> contrast up or down about one paper grade will result in a >> change in film speed of around 3/4 stop up or down. Changing >> either film conrast or paper contrast should have exactly >> the same effect on the print. >> >> --- >> Richard Knoppow >> Los Angeles, CA, USA >> dickburk@xxxxxxxxxxxxx >> >> ===================================================================== >> ======== >> ================================ >> To unsubscribe from this list, go to www.freelists.org and logon to your >> account (the same e-mail address and password you set-up when you >> subscribed,) and unsubscribe from there. > > ====================================================================== > ======== > =============================== > To unsubscribe from this list, go to www.freelists.org and logon to your > account (the same e-mail address and password you set-up when you subscribed,) > and unsubscribe from there. ================================================================================ ============================= To unsubscribe from this list, go to www.freelists.org and logon to your account (the same e-mail address and password you set-up when you subscribed,) and unsubscribe from there. ============================================================================================================= To unsubscribe from this list, go to www.freelists.org and logon to your account (the same e-mail address and password you set-up when you subscribed,) and unsubscribe from there.