Photo Engineer
Subscriber
Well, the workshop at the Formulary is over and the results were, as usual, mixed but overall good.
Coating quality of the papers was very good. The Azo type paper was a bit foggier than I wanted and lower in contrast and speed than my home made samples that I brought with me.
The Brovira/Kodabromide type paper was right on speed, equal to the Ilford MGIV paper comparisons, but again a bit low in contrast and a bit foggier than I wanted. I think we overfinished with sulfur in our exuberance! Thats what it looked like to me. The paper was about a grade 1.5, just by eyeballing the results. The fog didn't help evaluation of the contrast though.
The Ortho film was coated on both Estar and paper support. The coatings on film were low in quality due mainly to severe reticulation. This was most likely because we processed after only about 20 hours keeping and the hardener was not fully reacted. In any event, the film coatings were a good ISO 80 speed and the paper negatives were at least 200 speed. We experienced difficulties coating on the film support but not on the paper support. The emulsion appeared to be too low in viscosity. Addition of some gelatin boosted coating quality.
Appended is a sample scan of one of the negatives coated exposed and processed by one of the students. This is about a 2x3 area of a 4x5 negative. If you examine it, you can see two coating streaks and the reticulation. This was taken on a rather rainy, foggy morning over the central area of the Formulary by one of the students. The process was done using a Dektol equivalent at ~68 deg F for 3 minutes under red safelight.
Due to the high speed of the paper coatings, many of them ended up being foggy, but quite a few were good. The students seemed to go away happy and for that I am happy. We all learned a lot again.
This shows you that making good quality emulsions by hand and coating them with production quality is an art form that must be learned, just like any other alternative photographic system. It also shows that moving the making of the emulsions from site to site or from person to person involves a bit of 'fiddling' to get things right just as noted by Denise Ross on her web site. Each student was impressed with that fact, and was given the tools to make the required experiments on his/her own.
My thanks to the students and the Formulary.
I was also able to show them a comparison with Azo paper and my Azo like emulsion done by our own Alex Hawley. His 'gift' to me arrived in enough time for me to drag it along and show the students. My thanks to Alex.
PE
Coating quality of the papers was very good. The Azo type paper was a bit foggier than I wanted and lower in contrast and speed than my home made samples that I brought with me.
The Brovira/Kodabromide type paper was right on speed, equal to the Ilford MGIV paper comparisons, but again a bit low in contrast and a bit foggier than I wanted. I think we overfinished with sulfur in our exuberance! Thats what it looked like to me. The paper was about a grade 1.5, just by eyeballing the results. The fog didn't help evaluation of the contrast though.
The Ortho film was coated on both Estar and paper support. The coatings on film were low in quality due mainly to severe reticulation. This was most likely because we processed after only about 20 hours keeping and the hardener was not fully reacted. In any event, the film coatings were a good ISO 80 speed and the paper negatives were at least 200 speed. We experienced difficulties coating on the film support but not on the paper support. The emulsion appeared to be too low in viscosity. Addition of some gelatin boosted coating quality.
Appended is a sample scan of one of the negatives coated exposed and processed by one of the students. This is about a 2x3 area of a 4x5 negative. If you examine it, you can see two coating streaks and the reticulation. This was taken on a rather rainy, foggy morning over the central area of the Formulary by one of the students. The process was done using a Dektol equivalent at ~68 deg F for 3 minutes under red safelight.
Due to the high speed of the paper coatings, many of them ended up being foggy, but quite a few were good. The students seemed to go away happy and for that I am happy. We all learned a lot again.
This shows you that making good quality emulsions by hand and coating them with production quality is an art form that must be learned, just like any other alternative photographic system. It also shows that moving the making of the emulsions from site to site or from person to person involves a bit of 'fiddling' to get things right just as noted by Denise Ross on her web site. Each student was impressed with that fact, and was given the tools to make the required experiments on his/her own.
My thanks to the students and the Formulary.
I was also able to show them a comparison with Azo paper and my Azo like emulsion done by our own Alex Hawley. His 'gift' to me arrived in enough time for me to drag it along and show the students. My thanks to Alex.
PE