Responses interspersed below. ----- Original Message ----- From: <[EMAIL PROTECTED]>
> From: "Anthony Farr" <[EMAIL PROTECTED]> > > > > Exposure changes after filter changes are no problem if you have an > > enlarging meter. Just meter before the change, then adjust the > > filter, meter again, and the meter will indicate how much exposure > > you've gained or lost. > > That might be no problem, but it's still an extra couple of steps and > another piece of gear. > The few seconds that it takes to meter a printing exposure is far less wasteful of time than the minute or so that it takes to see the result of a guessed exposure or a test wedge. The first-time success rate with a good meter beats the first-time success rate of guesstimation anyday (I've worked both ways). Guesstimated exposures work best with fibre papers because they don't contain integral developer activators and will tolerate widely variable developing times better than resin-coated paper will. Exposure times for RC paper printing will accept only about 10% error (20% if you're not fussy). > > > > BTW do different brands of multi-grade papers still have mismatched > > contrast steps? I've only used Agfa for several years but prior to > > that each different brand I used had a different scale of filter > > settings for the various grades. > > Mine has 2 channels, one for Kodak, one for Ilford. They make it > sound like every paper will fall neatly into one of these categories, > but I don't know if that's true or not. > As for two channels covering all brands, Agfa paper is quite different to either Ilford or Kodak (at my last experience of them, anyway). The difference is mostly found in the grade 0 to 1 and 3 to 5 areas, but it's so long since I used other than Agfa that I forget if it's more or less responsive to changed filtration than other brands. But make side by side prints (including skin-tones) with Agfa and anything else and you'd forget about other brands, too. When I was changing over from Ilford Multigrade, I had to reprint the first half of the job I was doing because it was too far below the quality of the Agfa Multicontrast used for the second half to co-exist with it. Agfa MC has a long, linear tonal range in the skin-tones, the Ilford MG paper by comparison seemed to have a short and flat range in the skin-tones and no depth in the dark tones where the Agfa showed distinct tonal seperation. This was despite the overall contrast of the prints being identical. > > I think it would be a PITA if the > > contrast steps of a VCCE head only gave linear steps from grade to > > grade with one particular brand of paper. At least with a dichro head > > you can find the correct setting for ~any~ grade with ~any~ brand of > > paper. > > I'm not really following you here. Anything you can do with a dichro > head you can do with a VCCE head (well, except print color ;) ). It's > got stepless filtration too. > Point taken . The variable contrast heads I was familiar with have discrete grade steps so are unlike the Saunders/LPL unit. One type uses twin lamps, one with a magenta filter and one with a yellow filter. The output of each lamp is then varied to get the right colour mix for each grade, but the control is by an electronic panel that has only half-grade steps and has no channel options for different paper brands (why should Ilford cater for other brand papers, after all). The other type uses a simple rotary dial that drops a single appropriate grade filter into the light path, but does not use the two filters and compensating ND filter of a VCCE head. As your VCCE head is infinitely variable then I acknowledge you could use any value between the grade markings to equalise the results of different paper brands. Please excuse my ignorance :) Regards, Anthony Farr - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
