That's interesting, I never thought about it that way. It's the same 'local exhaustion' of the developer that will hold contrast down and prevent blocked highlights. Cool! Kinda "Zone system meets Minox". ;-)
Don > -----Original Message----- > From: Godfrey DiGiorgi [mailto:[EMAIL PROTECTED] > Sent: Wednesday, December 14, 2005 5:35 PM > To: [email protected] > Subject: Re: WTB: Minolta Dimage IV Scanner > > > I did most of my film experimentation in the past decade or so with > subminiature formats (Minox 8x11mm) becaust these tiny format > negatives show effects of processing much more clearly than working > with something even as large as 35mm, in comparative terms. > > Lots of experiments and precise control of process shows conclusively > that agitation speeds the development of dense areas and contributes > to grain growth/clumping. Leaving negatives sit in "still" developer > with minimal agitation tends to slow development in dense areas (the > active agents become exhausted locally, allowing development action > to continue in areas with lesser exposure), and grain clumping slows > quite a bit. > > My process for excellent Minox negatives with APX25 was to expose at > EI 50, process in XTOL 1:1 at 74F and use the time from Kodak's data > sheet plus 15%. Agitation is limited to 5 seconds at start, with a > sharp rap to dislodge bubbles, and then *one* tip of the development > tank by 20 degrees every two minutes, that tip taking 5 seconds. VERY > minimal agitation like this nets about 10-20% tighter grain (eyeball > estimate). > > Godfrey > > > On Dec 14, 2005, at 3:05 PM, Don Sanderson wrote: > > > I'm aware that aggressive agitation increases contrast > > substantially but have never heard/considered/noticed > > it having a pronounced effect on grain size. > > Could you elaborate a bit on this? > > > >> and use minimal agitation to > >> reduce grain growth. >
