Archived posting to the Leica Users Group, 2002/11/14
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]- --On Thursday, November 14, 2002 8:25 AM -0800 Adam Bridge <abridge@mac.com> wrote: > On 11/14/02 Nathan Wajsman wrote: > >> >> Actually, I do not think the negatives are underdeveloped. On the >> contrary, they may be slightly overdeveloped, since as you mention, they >> are properly exposed (there is shadow detail where I want it) but the >> highlights are too dense. I used the 13.5 minutes someone mentioned as a >> starting point but reduced is to 13 minutes since I use a Jobo. Next >> time I will try even less time, 12.5 or even 12 minutes. In general, I >> find that I need to reduce the times given in the film data sheets to >> compensate for the continuous agitation. For example, my time for Delta >> 100 is 15 minutes, and for Fuji Acros 13.5 to 14 minutes, both in XTOL >> 1+3 at 20C. Both of these times are shorter than what the data sheets >> suggest. >> > > Are you using a pre-soak? I note that the JOBO site says their times were > derived without a pre-soak, but someone, I think on here, said they > always use a pre-soak because it helps buffer the effects of the > continuous agitation. There is some confusion about whether presoak is "recommended" when using Xtol in a Jobo. The confusion results because Jobo says on it's website that presoak is not recommended with this developer. What Jobo really means is not "required". The reason for this is that Kodak went to the trouble of testing Xtol in rotary processors without presoak and published the recommended times, which are generally about 15% less than the times published for small tanks with inversion agitation. Kodak had never done this for other developers, so Jobo developed the 5 minute presoak recommendation which brought processing times almost exactly into line with the times published for small tanks with intermittent inversion agitation. So, it doesn't really matter. You can use no presoak and the shorter times that Kodak publishes for rotary processors or you can use a five minute presoak and the longer times published for inversion processing. If, like me, you have one of the automatic Jobos such as the ATL-1000 or ATL-1500, you don't have a choice as there is no way to turn off the 5 minute presoak when running B&W. So I use the longer times and get great results. - -- Rolfe Tessem Lucky Duck Productions, Inc. rolfe@ldp.com - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html