Invisible to Visible Silver Gelatin Prints

[Keo]

I know nothing about this process. I do know of a color process which was invisible to regular visible light but became a full color image under UV illumination.

PE

PE, that would be awesome to do as well. I haven't looked into color processes as much because I'm pretty well and truly set up for black and white at the moment. If you'd like to share that information that would be awesome to try in the future. Out of curiosity though PE, what reaction is happening when potassium iodide bleaches a silver print?

 

[Keo]

Keo can you provide a link. I'd like to give it a shot too.

I can and will: http://altphotolist.org/lists/alt-photo-process/2005/sept05/0353.htm

 

[Photo Engineer]

Keo, I have no idea what is going on here. I know that AgI is bright yellow.

PE

 

[Keo]

Keo, I have no idea what is going on here. I know that AgI is bright yellow.

PE

Hmm, I have no idea if this works or if I'm missing a context clue for the original post. However, I was revisiting this idea yesterday and wanted to know more about photochromism. After reading about it more I found that Transition lenses, that are made out of glass and not polycarbonate, uses silver chloride and copper chloride in the glass itself. I wonder if the photo-redox would take place without the glass; my thoughts are to melt the two salts together. Alternatively, could abandon metal salts and go to an azo dye, but I'm not a chemist and am not set up for that sort of magic.

Now I wonder if Copper Chloride and Silver Chloride are dissolved in a solvent would the same transition from clear to black take place? If it does, a potential vanishing and appearing picture could be made through the use of a gelatin coated paper sensitized with bichromate, the same process that is used to make "Sympathetic Photographs" using cobalt chloride salts. I might be over complicating things and sort of landed on a solution to achieve the effect above.

Photochromic pigments are readily available and I can not see why it couldn't be used to be ground into a watercolor paint and used in a gum bichromate process, carbon, etc.

Just wanted to give an update on some food for thought.

 

[pentaxuser]

Can we take it that in the ensuing 11 months you have been unable to try out or even begin whatever this process is that your link refers to?

It looks as if no-one else has tried it either. How do you intend to take this forward? I must say I am amazed that such a great trick isn't better known if it actually works. It sounds like the kind of thing that editors of those 1940s/50s photography magazine would have killed for in order to be able to run an article on it.

Thanks

pentaxuser

 

[Keo]

Can we take it that in the ensuing 11 months you have been unable to try out or even begin whatever this process is that your link refers to?

It looks as if no-one else has tried it either. How do you intend to take this forward? I must say I am amazed that such a great trick isn't better known if it actually works. It sounds like the kind of thing that editors of those 1940s/50s photography magazine would have killed for in order to be able to run an article on it.

Thanks

pentaxuser

The chemistry doesn't make sense as was suggested earlier in the thread. I haven't been able to dig up any information to back up the original claim of potassium Iodide and the vanishing photograph on Archive.org, Altphotolist, and the public domain scans of books on google. I've found other things similar to the effect like the photographic barometer and magic photographs, but not something with silver gelatin.

If there is a bleach that can bleach out a printed image from silver to silver chloride, then maybe you can saturate it in copper chloride? That is just a theory based on what little I know about the halide methods of Photochromic lenses. But at this moment, I'm more than likely gonna keep on digging and learning.

 

[pentaxuser]

Thanks for your reply. I wish you luck

pentaxuser