You seem to be very confused about what I said about EI. EI and ISO are
not the same. EI is the exposure index that a photographer will use for a particular film under particular circumstances. It may agree with the published ISO rating ... or not. There are many books by authors from Adams to Picker to (Phil) Davis which discuss and explain this. I said that TX (by which I meant Tri-X 400 in 35mm) works best
for me @ an EI of 250 or maybe 350, depending on circumstances, the meter used etc. (Yes, not all my meters are calibrated to each other.
And While water quality may not make a
huge difference in development times, it
can be an issue, hence developing times
are dependent on water composition. Not only is this my personal experience resulting in moving from one locale to another, others have this same experience, i.e. see
http://www.mironchuk.com/HC-110.html
Enlarger illumination is
not irrelevant, I have seen it with my own eyes in my own
professional work. Even if there is no enlarger involved, i.e., negatives will be scanned rather than optically printed, exposure and d-max achieved by developer and development time make a difference. It's a matter of physics. I for one don't just look at negatives ... I make prints or files for computer display. I don't recall Jarle asking for a "perfect negative for direct viewing only".
All I was saying to Jarle was that he will have to fine tune his methods based on testing or trial and error ... trial and error being a form of unstructured testing.
Oh, and by the way, I do know about the various Tri-X SKUs. I have been shooting Tri-X since about 1973 and have been through various iterations. In addition, I live in Rochester and some of the folks on the professional film products support line greet me by name when they see my caller ID.
I am more than certain that you produce great Tri-X negatives and the processing regimen you use works for you. I'm glad for that.
f2eyelevel said:
Times are for no means dependent of water source given that you process at 20C and even less of the type of enlarger (said with all respect to you, it's just plain irrelevant, the target here is how the negative will look, not what the printed picture will look once the negative has been put in the enlarger tray).
Jarle has asked for some advice to get some kind of universal developing basis and method, this is what I provided him, just because I have developed more Tri-X using the method I've described above and which I've got stuck with than you ever can do with your testing and testing and testing. I always got perfect negs, thanks to something that I haven't called the "magic bullet", but which is what all the great "developers" all around have said they've used forever, and which they wouldn't get away of.
As for the EI, well, there are now two Tri-X on the market actually, one called TX to be exposed at ISO 400 and the other one called TXP to be exposed at ISO 320, I think I had to mention this since your last sentence might have got Jarle confused a little bit more.
http://wwwfr.kodak.com/global/en/professional/products/films/bw/triX2.jhtml?id=0.2.26.14.17.20&lc=en
