Taking the advice of a friend, I have maded a modified SRAD (Single Run Ammonia Digest) emulsion. I then UF washed it using the method I've been developing.
In my first tests without sulfur sensitization, this emulsion raw, is as fast or faster than the ISO 40 emulsion I've made before, so when I chemically sensitize it with sulfur or sulfur+gold, this beast should be at least ISO 100, or maybe higher.
As George Eastman said.... "pray for the emulsion".
I'll be testing it against a raw version of the previous emulsion. We shall see. I may have goofed but I may have a new emulsion.
I am preparing a post on my hybrid Kodabromide / Brovira emulsion if anyone is interested.
this seems to be extremely complicated and specialised work for which you are to be commended
however, for the rest of us who care about analogue/traditional/alternative photography may it not be better to learn about and hone our skills using the non-silver processes?
wouldn't non-silver be more do-able, cheaper and rewarding for non-chemist/engineer types?
You have an exellent point. But OTOH, you have to remember that silver halide in gelatin is the only medium that can get you above about ISO 1, give you spectral sensitivity, and allow a very large ability to control contrast. So, other than that, you are right.
Also, if Kodak, Fuji and Ilford go out of business or falter in any way and we emulsion makers are all gone (there are about 200 WW and we are rather oldish now) how will you make anything that is silver-gelatin unless it is passed on.
So, I can quit doing this. After all, all it does is cost time and money, or I can go on. I apologize if this is patronizing but it cannot be said otherwise regarless of intent. So, what do you want Ray?
Possibly, but there's plenty of information on non-silver processes in the public domain already, and relatively little about silver.
Originally Posted by Ray Heath
Besides, I suspect Ron isn't doing this work just for us - he enjoys it. Personally I'd prefer he post his results than keep them a secret!
And what about the chemist/engineer types here?
Keep up the good work Ron.
p.s. fingers crossed for the emulsion
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The only non-silver process which gives a sensitivity comparable to silver/gelatin emulsion is based on silicon. Being what it is, that's off limits for this forum.
Originally Posted by Ray Heath
There are many people who know a lot about non-silver printing processes, and most of those processes are simple enough that anyone can do it given the right chemicals and a simple "cookbook recipe". But since these all have relatively low sensitivity, they are not really usable for in-camera use.
There is a very good reason why non-silver processes have been "alternative" almost since the beginning: They are very limited in terms of speed, spectral sensitivity, and contrast control.
Some few people put a tremendous effort into preserving and expanding our knowledge of silver halide/gelatin emulsion making. One effect of this is that there is now some reason for optimism: If all commercial film production stopped tomorrow, there would still be some people who could set up small-scale emulsion "kitchens" and eventually produce film and papers.
-- Ole Tjugen, Luddite Elitist
i just want to know when the book full of all of these fantastic chemistry we hear about will be published. and well I will also need the secret decoder ring, and about a masters in chemistry. Although i hear you can order one of those on the internet
Tommy, I have about 1/2 of the book done and about 3/4ths of the experiments and data ready. I have Disk I of the DVD ready. I am now working on things that people have pointed to and said "you left that out" and etc. These include emulsions faster than 40, double run emulsions and UF washing. These are all things mentioned recently.
You will not need a secret decoder ring, but you will need to know two things. One is the chemical names of what you are using, and two is what they do when mixed together. I'll probably think of a few more, but basically Ag is silver, AgX is any silver halide, AgI is silver iodide, and etc. Not hard, is it?
Let me know what you think.
this is great news ron!
i can't wait to hear and see the fruits of your labor
keep up the great work!
I look forward to the day of enlightenment.