Delayed processing of Ultimate

Silverhalide Emulsions / Chemistry.
jeff-blyth
Posts: 20
Joined: Sat Feb 18, 2017 9:41 am

Re: Delayed processing of Ultimate

Post by jeff-blyth »

Perhaps Valery's post gives a clue to any latent image fading problems. When he kept the exposed film wound in a roll , there was no problem.
In a roll form there is no free access of oxygen is there? so any weakening of latent image is perhapscaused by ariel oxygen and damp air. I wonder if it would help to put exposed stuff in a container in which you could squirt in some CO2? But the easiest practical way might be to simply sandwich the exposed stuff between say plastic sheets to stop free oxygen access.
Valery
Posts: 275
Joined: Fri Jan 09, 2015 12:42 pm
Location: Yaroslavl , Russia

Re: Delayed processing of Ultimate

Post by Valery »

Still it can be useful.
Now I mainly manufacture on glass. I cover the plates 280x406 mm.
Drying the horizontal distance between the plates is 2 cm. All plates lie emulsion up. There is not very intensive blowing with dry air.
After drying, I put all the plates in cardboard boxes by laying a polyethylene tube cut along them along the edge.
But one day I made too many plates and the tubes ended.
I was too lazy to do them. I just put the plates on top of each other without gaskets.
It turned out that these plates were better preserved and when producing holograms they showed DE as if they were completely fresh.
Now I always keep glass plates so I just put them on top of each other.
So, that would dry emulsion contacted with glass.
Valery.
Ed Wesly
Posts: 513
Joined: Wed Jan 07, 2015 2:16 pm

Re: Delayed processing of Ultimate

Post by Ed Wesly »

And this is why Ultimate plates come vacuum packed.
"We're the flowers in the dustbin" Sex Pistols
Sergio
Posts: 101
Joined: Tue Jan 20, 2015 12:25 pm

Re: Delayed processing of Ultimate

Post by Sergio »

My hypothesis is that Ozone in the air can affect markedly some cyanines dyes present in the emulsion, this is absolutely correct for at least for one dye used in biochemistry (red sens. dye). However how oxygen could have some effect on the dye? By oxidation?
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