Emulsion making data
At Kodak, we modeled emulsions, made them and then compared the run-time data with the modeled data for accuracy.
This gave us a feeling for the model, and also told us what took place in the kettle as we made the emulsion.
We had a rich history in mathematics related to emulsion making, and this is reflected in the dozens of patents and publications on this subject. These publications seem to have been generally overlooked.
In any event, attached is a run time plot of a pure chloride (Azo type) emulsion made actually for Supra color paper. These too were pure chloride emulsions which were either treated to add epitaxy after the make or which had an Iodide compound added to increase sensitivity. Supra and Endura chloride emulsions could approach ISO 25 in speed.
The data is courtesy of Dr. Bruce Kahn.
Two things of note. The 'bobble' in salt flow at the start of the make is due to an incorrect PID setting, and the general salt flow overall overruns the silver flow due to the increasing ionic strength. This is all seen in the equations applicable to this, for those that are interested.
Afterthought to Simon Galley and the staff at Ilford. This is a freebie from Bruce's course at RIT.
Last edited by Photo Engineer; 04-16-2008 at 10:49 PM. Click to view previous post history.
Reason: Adding a personal note.
Well, there went some good info... Did someone make a Foto3 comment?
Last edited by Kirk Keyes; 04-18-2008 at 03:03 PM. Click to view previous post history.
Reason: freudian typo
Some of the material was already covered here before, in other threads.
So if I want comments from Ryuji and Ron on the same subject, it looks like I need to post two threads - one directed at each of them. And then later, we can get the mods to merge the 2 threads together I suppose...
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Originally Posted by Kirk Keyes
It sounds like information got deleted (?) I know you wouldn't complain otherwise. Some of this stuff is too valuable to lose. Is there any way you can recap the gist of what got zapped? I think I might get in the habit of printing pages that look interesting. Apparently you never know if they'll stay put.
Like that's never happened on this site before...
Originally Posted by rmazzullo
What gives? I'd been following this thread and saw no reason to delete it wholesale. Hell, at this rate, they might as well have deleted the whole thread; there's nothing left anyway.
"I only wanted Uncle Vern standing by his new car (a Hudson) on a clear day. I got him and the car. I also got a bit of Aunt Mary's laundry, and Beau Jack, the dog, peeing on a fence, and a row of potted tuberous begonias on the porch and 78 trees and a million pebbles in the driveway and more. It's a generous medium, photography." -- Lee Friedlander
You're kidding, right? Did you take a good look at the attached graph?
OK, Bob. Would you care to go over the data in the graph and recreate the analysis that Ryuji did? A lot of people here and not well versed in interpreting data from graphs alone.
I will not do any analysis, because Photo Engineer did it correctly from the start, in spite of best efforts to confuse the subject.
It is important to decide who has the right and the wrong information --- and what the motives are behind the scenes. Who stands to gain what, exactly?
Once you determine that, your analysis will be complete. I go by what I see. I have seen examples. I have had the benefit of someone else's guidance using example after example, explaining theory and procedure, mistakes, and small changes in procedure and components that make all the difference in the result, gained from years of first hand experience. In phone call after phone call, using illustration and references to other texts to make the point clearer. That same person explained to me the reasons for certain decisions and the effects gained in a few particular patents --- sort of filling in the blanks, as it were. Again, first hand knowledge.
I will be damned if I listen to anyone who claims the same level of expertise or experience, without a single shred of proof. Further, they add insult to injury by refusing to post any examples, prior work, mistakes, or procedures of their own. It's the same story over and over and over again.
You can be hypnotized all you want by the flowery technobabble, but its existence doesn't guarantee that it's correct. Any pharmaceutical drug rep can tell you that. (How many people did they kill today?)
You can spout all the technical gobbledygook on the planet, but if you can't show me results, what's your point?? Perhaps there are other agendas in play which have a vested interest in making sure emulsion making never really gets off the ground in a big way. Far-fetched? Apparently not at all.
You yourself said it best. "OK, Bob. Would you care to go over the data in the graph and recreate the analysis that Ryuji did?"
Now, why would I want to do that?
At some point in the not too distant future, the real information flow will stop, and then you will have to trust that what you are left with is correct. What if you discover that "material" is not correct at all? Well, I guess then that particular party (or parties) can make emulsion, but they will have made sure the rest of us won't be able to. Is that how it's supposed to go?
Last edited by rmazzullo; 04-19-2008 at 06:51 PM. Click to view previous post history.
Reason: corrected typo