Archived posting to the Leica Users Group, 1999/10/13
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Christer Almqvist wrote: > > I figured out Mark meant 1 +3, and I guess he used an e.i. of 400, but I > have no clue how he agitated. > > Let me add a few comments: > > 1. if you use Xtol at high dilutions, be sure to use enough stock solution, > at least 100 ml per film. I have found 1+1 dilution gives better result > than 1+0, but I fail to see the advantages of higher than 1+1 dilutions > ><Snip> To quote Silvia Zawadski and Dick Dickerson the lead inventors of Xtol: "What, exactly happens when Xtol (or any other black and white film developer) is used at higher dilution? • Development times get longer. • Real film speed (shadow detail) improves, slightly • The image is slightly grainier • Sharpness is a little bit better. Snip All of these effects are more pronounced the greater the dilution (as referenced earlier, there are practical limits here-too little volume of a too-dilute solution, and the film never fully develops) These same effects can (for the same reasons) be created on a smaller scale by agitating less often during development (again their are practical limits based on maintaining good uniformity.) Further, the two are additive: dilute more and agitate less often and the changes in development time, real speed, graininess and sharpness are larger than with either change alone." From Photo Techniques Sept/Oct 1999 I agitate once per minite by medium speed inversion but somtimes I roll the tank on the sink at a medium speed. I think it likes that. I presoak dispite what they say about that now. The whole first minite I agitate and often roll (both directions). And I bang the thing when I put it down to jar out bubbles. So I do Shake Rattle and Roll but not to hard! Mark Rabiner