Gerald C Koch
Allowing Ads
he also begins with soaking the paper in a solution of sulfuric acid. The acid is thus in the gelatine before the bleaching agent. Then he sticks to times, one sees him observe and can hear his .
If you watch the video carefully then there is a lot you can find out.
Since a halide must be present it could be hydrochloric acid that he is using. Halide ions and acidity in one.
But not without a healthy background in chemistry, Mr. K, which I do not possess
That's something I didn't know (or understand) before. You've succeeded once again in educating me a bit further!
OT, I suppose that must be part of the way a Chromium intensifier works?
Yes, just like IN-4. Which brings up a question. Just what is patenting? It must be something new or novel. But Japanese patent law may be different from the US and UK.
Or it could be a mis-translation. Despite living in Japan I don't speak Japanese well enough to comment on the official translation, but living here I know that sometimes there can be a disconnect between what people SAY they have done and what they have ACTUALLY done. Who knows what he patented - maybe his intuition? (the process cannot be taught to anyone after all...)
This thread shows that a number of people here can make some pretty good educated guesses as to what he is using, and could probably figure it out with time and patience (he himself failed over 1000 times...though I hope that they made copies of those photos beforehand).
The potassium permanganate bleach is formed by:
Pot. permanganate ................0,4g
Sulfuric acid ...................0,4ml
Sodium chloride....................10g
Water...............................1L
Funny things patents. Someone actually owns a patent on the blinking colon for digital clocks and time displays.
Funny things patents. Someone actually owns a patent on the blinking colon for digital clocks and time displays.
Perhaps a clue can be found in this article: http://unblinkingeye.com/Articles/PBR/pbr.html
http://holowiki.nss.rpi.edu/wiki/Silver_Halide_Sensitized_Gelatin also lists a rehalogenating permanganate bleach.
Interesting, but the bit I liked was the use of the mini-tray with holes to transfer the print to other solutions without touching it.
So what is the purpose of soaking the print in sulfuric acid?
You are right, I confused things. He prepares an acid solution, I still believe it’s sulfuric acid he gives two drops of in water, and adds it to the permanganate solution. We don’t know what he first bathes the print in. I don’t think it’s for hardening the gelatine, the photograph is 70 years old. That I can read from the subtitles when the lady is visiting him. Well, I shouldn’t harden such an old gelatine. Maybe a buffer for the bleach, like phosphates.
The whole thing bears a little secret. We don’t know whether he made a safety duplicate before the chemical treatment. That could be a repro shot or a contact reflection internegative. When you know that the photograph someone brings you is all they have you don’t want to be lost with a mistake ruining the unique copy.
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?