Photo Engineer
Allowing Ads
The book and DVDs are moving. Modest but nice sales with some good comments. My thanks to all. It will take some time to see if sales justify a Volume II, "Advanced Photographic Emulsion Making and Coating" (or whatever).
It might be useful to comment on the negative remarks made by some on these topics though.
It has been suggested that I am trying to "force" the Kodak method on the emulsion making community. Well, I have to say that what is true at Kodak is also true at Fuji and Agfa and Ilford. After all, science dictates this to emulsion makers, not me, and as I say in the book, form follows function.
Ok, so how do I "dictate"? The Azo type emulsion came from a teaching formula at RIT.. I modified it with the help of Dr. Bruce Kahn from RIT and a former EK emulsion maker. I improved it by reducing aggregate formation, pepper grain, and also improved speed and repeatability. I also learned how to make it in 3 grades. I could not get (at that time) all of the chemicals for making "real" Azo, and one method escaped my attention. So, I used a method from Agfa Lupex to control contrast which turned out to be almost identical to the Kodak method after I had looked into the methods involved. You see, form follows function. Kodak used a different chemical but got the same results.
Anyhow, to continue, the Kodabromide like emulsion is a molar conversion of the Azo type emulsion with mass redistribution to compensate for contrast, speed and the tendency of AgBr to be even more aggressive in formation of aggregates. No Kodak, Fuji or Agfa involved at all here. Just Trial and Error (T&E). It works. However, where Kodak used Cadmium and Mercury, I substituted methods used by Agfa and also known by me to work. This was to make it more palatable for use in home darkrooms.
The ISO 40 emulsion came straight from Baker, but I modified it to make it more repeatable and also I updated the sensitization step due to the lack of active gelatins. Oh, the same goes for the above as well in case you wondered. Again, no Kodak or Fuji. No agfa either. And again, it required a lot of T&E.
Last but not least, I worked hard to get those coating blades made. They use a tried and true method that came from EK and others, including the paint industry. It is claimed by some that these blades have an inherent design fault. Frankly, if there is one, the claimants don't say what it is but I am aware of none. Many people out there are using them. The blade is used at EK in 4 forms, one for paper and three types for film. The purpose of the heavy blade made of SS is to hold the support down flat, keep the emulsion in the "well" hot, resist corrosion, resist scratching and spread evenly in quantity and width over the surface of the support without wearing away or changing undercut. Other materials don't do all of this.
So, the idea of a coating blade like this was endemic to the industries that needed to coat uniform thin layers over a broad width. Kodak coated up to 42" using this basic method. I tried other methods, but this is the best and the least messy. Wire wrapped rods come in second IMHO. We go downhill from there.
Anyhow this one does involve Kodak, but also any industry that uses coatings. There are many of them out there and I really don't care what anyone uses. I merely wanted to get a high quality method out there as there are so many low quality methods out there, or so many of dubious quality. After all, you can use a paintbrush to apply the emulsion, but every time I bring it up, the students try it and are not really satisfied with the results even if the coatings are unique in appearance, or the students just refuse to try it at all. Why, you can even soak your paper support in the emulsion in a tray or float it face down on the emulsion in a tray to coat it.
So, there you have some of the back story about the response to the book and the methods presented in it and some of my answers.
About the only Kodak thing I use is Kodak terminology for many of the items involved. I have a multi page dictionary in the back of the book to help the reader on that. If there are any Fuji, Agfa or Ilford people willing to present their work, I have yet to hear from them. They could write interesting books themselves I'll warrant.
Thanks all for the response.
PE
It might be useful to comment on the negative remarks made by some on these topics though.
It has been suggested that I am trying to "force" the Kodak method on the emulsion making community. Well, I have to say that what is true at Kodak is also true at Fuji and Agfa and Ilford. After all, science dictates this to emulsion makers, not me, and as I say in the book, form follows function.
Ok, so how do I "dictate"? The Azo type emulsion came from a teaching formula at RIT.. I modified it with the help of Dr. Bruce Kahn from RIT and a former EK emulsion maker. I improved it by reducing aggregate formation, pepper grain, and also improved speed and repeatability. I also learned how to make it in 3 grades. I could not get (at that time) all of the chemicals for making "real" Azo, and one method escaped my attention. So, I used a method from Agfa Lupex to control contrast which turned out to be almost identical to the Kodak method after I had looked into the methods involved. You see, form follows function. Kodak used a different chemical but got the same results.
Anyhow, to continue, the Kodabromide like emulsion is a molar conversion of the Azo type emulsion with mass redistribution to compensate for contrast, speed and the tendency of AgBr to be even more aggressive in formation of aggregates. No Kodak, Fuji or Agfa involved at all here. Just Trial and Error (T&E). It works. However, where Kodak used Cadmium and Mercury, I substituted methods used by Agfa and also known by me to work. This was to make it more palatable for use in home darkrooms.
The ISO 40 emulsion came straight from Baker, but I modified it to make it more repeatable and also I updated the sensitization step due to the lack of active gelatins. Oh, the same goes for the above as well in case you wondered. Again, no Kodak or Fuji. No agfa either. And again, it required a lot of T&E.
Last but not least, I worked hard to get those coating blades made. They use a tried and true method that came from EK and others, including the paint industry. It is claimed by some that these blades have an inherent design fault. Frankly, if there is one, the claimants don't say what it is but I am aware of none. Many people out there are using them. The blade is used at EK in 4 forms, one for paper and three types for film. The purpose of the heavy blade made of SS is to hold the support down flat, keep the emulsion in the "well" hot, resist corrosion, resist scratching and spread evenly in quantity and width over the surface of the support without wearing away or changing undercut. Other materials don't do all of this.
So, the idea of a coating blade like this was endemic to the industries that needed to coat uniform thin layers over a broad width. Kodak coated up to 42" using this basic method. I tried other methods, but this is the best and the least messy. Wire wrapped rods come in second IMHO. We go downhill from there.
Anyhow this one does involve Kodak, but also any industry that uses coatings. There are many of them out there and I really don't care what anyone uses. I merely wanted to get a high quality method out there as there are so many low quality methods out there, or so many of dubious quality. After all, you can use a paintbrush to apply the emulsion, but every time I bring it up, the students try it and are not really satisfied with the results even if the coatings are unique in appearance, or the students just refuse to try it at all. Why, you can even soak your paper support in the emulsion in a tray or float it face down on the emulsion in a tray to coat it.
So, there you have some of the back story about the response to the book and the methods presented in it and some of my answers.
About the only Kodak thing I use is Kodak terminology for many of the items involved. I have a multi page dictionary in the back of the book to help the reader on that. If there are any Fuji, Agfa or Ilford people willing to present their work, I have yet to hear from them. They could write interesting books themselves I'll warrant.
Thanks all for the response.
PE