Ray;
I have posted both my fixing test procedure and my developer stability and quality test procedure, the latter with results. If you wish, I will re-do this if you really feel it is necessary. Sorry you missed it elsewhere.
True- I have not seen the developer stablty/quality test procedure; I WOULD like to see it. Perhaps someone knows where it is and you won't have to go to all the trouble...
...to summarize, a fixer can be easily tested with 3 solutions.
1. Silver Nitrate in Acetic Acid - Hypo retention test
2. Sodium Sulfide in water - Silver Halide retention test
3. Potassium Iodide in water - Fixer exhaustion test
Instructions are supplied with kits sold by major suppliers of photochemicals. Testing is simply seeing how well a fixer performs in a given sequence of fix time, dilution and wash.
PE
Are these 3 the same that appear in the Kodak darkroom data books?
They all 3 sound very familiar, but are these the tests you used on
SFI -SFVIII?
How do you test for capacity?
Do you controll for silver weight?
Degree of exposure?
I think perhaps I was not clear enough.
What I am interested in learning is your thought process as you worked your way from SFI to SFII...
What promted you to change SFI ?
What were you trying to improve?
When you finally had SFII, what was wrong with it?
Why did you feel the need to change that one and develop SFIII?
Same for SFIV, V, VI and VII...
Why did you find it necessary to keep changing or tweaking?
Is SFVII really any better than SFI?
By how much?
How much improvement has been made between SF VII and SFVIII?
Is the improvement tangible?
If SF VIII is so good, why couldn't you go directly from SFI to SFVIII?
What has enabled you to create now what you could not create earlier?
I don't know if you see what I am asking, but it is the thought process I am interested in and that all too often gets swept under the rug or discussed behind closed doors.
Was SFI buffered?
We are missing a very valuable exercise by not being able to actually follow you through a product's development. You have alluded to it yourself, there is a need to cut corners... to see which corners you cut, how you cut them, and your reasons... could help others who like yourself, are independent researchers, but unlike yourself, do not have the insight that comes from working where you have.
SF series is mentioned here only as an example.