Archived posting to the Leica Users Group, 2002/01/05
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]> Date: Fri, 04 Jan 2002 22:25:25 -0800 > From: Mark Rabiner <mark@markrabiner.com> > Subject: Re: [Leica] Re: Jobo CPE-2... > Message-ID: <3C369C54.F4A44CC0@markrabiner.com> > References: <200201041904.LAA02870@mejac.palo-alto.ca.us> <3C365C38.7050203@ldp.com> > >><Snip> > >> John, >> >> This is not at all misleading on Jobo's part. If you use D76 stock or >> D76 1:1 for example, you will be well within the limits. Or for that >> matter, any of the C41 or E6 chemicals will work fine since with those >> chemicals you are generally trying to use the *minimum* necessary to >> develop the roll instead of playing with extreme Xtol dilutions. >> >> What you must appreciate is that it takes a certain amount of stock >> developer to develop a roll. You cannot dilute infinitely and still get >> an image on the film. >> >> Xtol, which we have been discussing, requires 100ml (per Kodak) of stock >> to develop a roll of 35mm film. If you dilute 1:3, that's 400ml of >> solution. If you want to develop 4 rolls at that dilution the tank >> would have to hold 1600ml of solution, which it does not. >><Snip> > -- >> Rolfe Tessem >> rolfe@ldp.com >> NYC >> >> -- > > Rolfe I'd recommend instead of taking what you read as gospel and then > repeating it as such trying it out for your self. > The 100ml limit per roll of Xtol is only true for 2 films so far. TMX > and Delta 3200. > I an many other people have many negs to prove it. And prints and scans > from those negs. > Those negs are fine. Full bodied. Rich in nutrients. > > > Mark Rabiner > Portland, Oregon USA > http://www.markrabiner.com Mark, It seems that the Xtol discussion has evolved into a debate over two points. 1. Whether the Kodak recommendation of 100ml stock solution per 8x10 film area is wildy conservative and can be safely ignored. and 2. Whether dilutions beyond 1:1 can be safely used -- despite Kodak's withdrawn recommendation on using these dilutions -- especially as the stock developer ages. Obviously, you are doing both of these things successfully and that's great. Your results speak for themselves. However, I'm not just taking what I've read in some magazine piece or on the net and repeating it as gospel so your comment is a bit unfair. These are the manufacturer's own recommendations, reached after its own extensive testing. To completely discount them seems somewhat cavalier in itself. It may be that Kodak has taken into account the varying alkaline content of local water around the country and you're just lucking out. It may be that they've tested numerous film stocks in Xtol and some soak up more developer energy than others and you don't happen to use those stocks. It may be that Kodak has built in a safety factor and you're cutting it to the bone. My point is simply that I don't think the recommendations come out of thin air. One has only to read other forums to see that many, many people have had failures with Xtol. As to myself, I've been using Xtol for a couple of years and like it immensely (and have never had a failure). I've used it to develop film in all formats from 35mm to 8x10, using Tri-X, all four Delta emulsions, Neopan 1600, and even Bergger BPF 200. As I pointed out in another posting, dilutions greater than 1:1 aren't really practical for me as I primarily use a Jobo ATL-1000 and the tank capacity works against greater dilutions. I would love to see someone post comparative results from the same material shot on the same film at the same time (with a Leica, of course, just to keep this vaguely on topic) processed 1:1 and 1:3. Again, according to Kodak, going to 1:1 from straight stock results in enhanced sharpness, slightly increased film speed, and slightly increased grain. My own results suggest that this is true. My question would be, which of these three results changes for you when going from 1:1 to 1:3 dilution and to what degree? - -- Rolfe Tessem rolfe@ldp.com New York City - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html