Well, not entirely--let me explain a bit better--this "new way" to explain occurred to me:
The film speed for those reversal cine films is not determined for just ANY reversal process, but for those machine processes with very fast acting first developers. Those machine processes are extremely difficult to do with home processing equipment, so there's no point in even trying--not enough "slop" in the process.
That being the case, I decided that I wouldn't even try to compete with the machine or it's tightly controlled process, but, instead, find a process that works with the equipment and time at hand. If "maximum attainable" film speed cannot be achielved, then this is an acceptable trade off--the 2/3 stop or so is not worth the time and expense of buying/maintaing a processing machine that can duplicate the process for which the film was rated.
I tried the hypo and, after reading the monobath book, have determined that hypo processes must be done VERY QUICKLY to keep the hypo "bad effects" from ruining the results. Such short processing times are not worth the bother trying to get them to work--particularly with large sheet films--pretty much impossible to control when you're filling/emptying times are significant compared to the ideal processing times.
Not only that--if you get a process that works for one film using a hypo developer, it likely won't work for another film because of the different effects of different fixing rates. So a more slowly fixed film like tmax will react MUCH differently to a hypo developer than tri-x. However, if a reversal process is based on a first developer with no hypo, then it is more universal in it's application to different films. So you get one process for many films rather than having multiple fussy processes for each different film.
The conclusion I have come to is that hypo in the first developer is just not worth the aggrivation for home processing.
The main point--them reversal film speeds are measured for the MACHINE process--not just ANY reversal process. Hypo is not a "magical ingrediant" that is necessary--it is only necessary for that particular process.
ALSO--hypo first developers generally require the first development to be carried out very quickly for satisfactory results--10 minutes in any hypo first developer will result in way too much silver halide removal-it'll ruin the dmax. So if you can perfect 3 minute first development times, then maybe the hypo first devleoper will work out for you. I don't think any processs which requires hand filling a quart of liquid is going to allow any kind of uniformity/repeatability for a 3 minute process.
You'll see.....it took me years....you'll go throught the same, since you want to learn it yourself, just like I did.
READ THE MONOBATH BOOK.
Last edited by johnielvis; 03-19-2013 at 05:57 AM. Click to view previous post history.