Archived posting to the Leica Users Group, 2001/02/22
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 11:41 PM 2/22/01 +0100, Julian Thomas wrote: >> Want a good 400 film... Tri-X in Xtol 1:3 by hand, 1:1 in a JOBO. SHARP! >> > I use xtol 1:1, 24deg 8 mins for Trix. I see a lot of people using 1:3. >What differences would I see if I dev 1:3 - are people doing this for >economy only? > >Julian There is no economy in using Xtol 1:3. It takes the same amount of raw developer per roll (100ml per 135/36 roll) regardless of the dilution. Mark Rabiner compensates by extending the time. I have always used 1:3 in Stainless Steel hand tanks and I currently use 1:1 in my JOBO. But I will also use 1:3 in the JOBO, I just haven't taken the time yet to do the appropriate tests. 1:3 gives a little more edge effect than 1:1, and a little more grain which makes the result look sharper. But in reality, the difference is easily missed. You have to know what you are looking at. If you have a 1000ml tank which holds four rolls of 35mm film. Mix Xtol 1:3. In 1000ml of 1:3 Xtol, you have 250ml of raw developer. This will properly develop 2.5 rolls of film. I put three rolls in plus an empty reel. In a 500ml tank, I put in one roll and an empty reel. In an eight roll tank (2000ml) I put in six rolls plus two empty reels. This is fudging a little bit. Mark doesn't. He fills them up with film and extends the time. And it is useless to ask people what their development times are for these kinds of situations. This is at the edge of Xtol's capabilities and the square inches of emulsion vs milliliters of raw developer will make a big difference. If you have a time that works for four rolls in 1000ml of 1:3 Xtol, this time will not work if you only put in only three rolls. You are working at the exhaustion point of the developer for the last 25-50% of the development time, bromide is at it's highest concentration, and a fine line is walked to get consistent results. Change anything in the equation and you get something you did not expect. Either very thin, or very heavy negatives. This is why personal testing, trial and error, lots of mistakes, will eventually give you your own "formula". Not necessarily suitable for anyone else. My JOBO can deliver 1000ml so I need to experiment for development times for 1:3 dilution and four 135/36 or two 220 (four 120) rolls. Kodak used to publish data for 1:2 and 1:3 dilutions but because people didn't read the fine print (100ml per roll) they were getting underdeveloped film. And complained. So Kodak said screw it... we'll pull support for higher dilutions. Jim NO UV