View Full Version : Our Recent Silver Bromide Gelatin Emulsion Workshop

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Photo Engineer
01-24-2014, 12:15 PM
The program you have is not COMPSELECT then. It sounds like a blend of portions of the COMPSELECT ported to BASIC and blended with KEDS (Kodak Emulsion Design System). KEDS was (is?) far more comprehensive in capabilit as it produces the code to run the process control equipment directly along with the model and error messages.

All of this was to be replaces by ESP (Emulsion Scaling Program).

I build my electrodes from Silver "wire" as shown in the book, and plate them as described. But using them in critical situations requires a bridge of neutral salts to prevent Cl contamination of the make. The double junction electrode "leaks" Cl enough to disturb measurements. The book shows examples of a bridge.

There is so much more to this that you are missing which I left out of the book as I did not want to get overly complex. You see, even what you have is a dumbded down version of what we used which was capable (in the end) of handling up to 60 segments, but generally handled 25. That was an average make, not 15.


01-25-2014, 06:00 AM
Here are the two references I found online while searching the topic of VAg. These are the programs I am referring to. Although they are old as you indicate, they are a step above pushing a syringe plunger with ones thumb.

The first is a patent document that contains the COMPSELECT program in appendix A.

The other is the RIT paper which also has a Program listing in the Appendix.



Photo Engineer
01-25-2014, 01:45 PM
Thanks. The problem is that no interpreted BASIC program is fast enough for this type of work, and a compiled BASIC program is just on the edge of being fast enough. What was needed was a C++ DLL that could be run in the background to do the work.

See my PM.


01-25-2014, 08:46 PM
The Natan thesis is very interesting and useful. I've built the setup shown on page 13 and it works quite well. One of my plans this winter was to actually try to follow the data for a controlled make. Haven't gotten that far yet, though.

Thank you for the additional patent reference. I don't think this one is in my library.

For all practical purposes, BASIC is no longer interpreted - although microsoft has taken a step back in that direction. Knowing the effort that Eastman Kodak dumped into the development of the C++ language (along with other companies) I am glad to see they put it to practical use. QNX was quite popular in those days. In many ways the mid-90's were the end of the golden age of computer science.

-- Jason

Photo Engineer
01-25-2014, 09:04 PM
There are several more patents referenced in my book on vAg measurements. Most notably are those by Judd and Lin.

I was charged with developing a method of process control for the PC and had ordered the Burr Brown board for the core controller. At that time, a new hire came in named Yun Chang. I was asked to turn all of my hardware and notes over to him and in the end, he and several others did a wonderful job of turning it into reality. I doubt if I could have done as good a job. You see their names on the patents and some appear on the article by Natan.

However, it should be noted that this work is old. When it appears, it is nearly 10 years out of date. The "current" status of COMPSELECT, KEDS, ESP and other internal programs is far beyond what is shown.