diff --git a/README.md b/README.md index 6ae9e45..f7b6af8 100644 --- a/README.md +++ b/README.md @@ -42,6 +42,44 @@ agitation can be made to work reliably and produces useful results ... at least for me. +## tl;dr + +Oh, you're one of those impatient types, eh? Here is the short form. + +High dilution, low agitation works fine if you: + +* Minimize contact between the film and its support structure. That + means pinch style hangers for sheet film or using stainless steel + reels for rollfilm. Avoid framed sheet film hangers or plastic + sheet film contraptions like the Yankee system. Avoid plastic, or + high-walled rollfilm reels. Use Nikor stainless steel reels for + rollfilm to minimize film contact. + +* Get the film off the bottom of the tank so gravity can pull away + development byproducts. That means hanging sheet films horizontally + using pinch style hangers. It means inverting a funnel in a double + height tank to suspend a stainless rollfilm reel well above the + bottom. + +* Whether you do semistand or EMA, you need a good, vigorous + agitation at the beginning. 2 minutes for semistand or 90 seconds + for EMA seems to be about right. + +* As of this writing (5/2024), it looks like higher dilution with EMA + is preferrable to lower dilution with semistand for normal or long + Subject Brightness Ranges - at least with Pyrocat-HD. I've found + that semistand with Pyrocat-HD, even at 1.5:1:250 still jacks up the + contrast too much. EMA for an hour with three agitations (90 + seconds initial, 10 seconds at 21 & 41 minutes) at 1.5:1:300 seems + to work better. At this dilution, you'll get about 1/3 stop less + than box ASA speeds. + +* When faced with a low contrast or short Subject Brightness range, a + lower dilution semistand (1.5:1:250) for an hour seems to work best. + Begin with 2 minutes agitation and one 15 second midpoint agitation + at 31 minutes. At this dilution, you should pretty much get box ASA + speeds. + ## Introduction @@ -479,7 +517,7 @@ The worst offender here is EMA. The repeated agitations drives up edge effects far more so than does the 1 midpoint agitation of -Seminstand. Given a subject with a lot of midtone texture and local +Semistand. Given a subject with a lot of midtone texture and local contrast, you might prefer Semistand with a film like Shanghai GP3 or Agfapan APX 100. Of course, conventional development is always a thought if the dynamic range of the scene can be properly managed.