Summitar and Thorium versa Uranium Prints

[Mustafa Umut Sarac]

Hi there ,

Chris posted his uranium toned prints at a thread named Radioactive Prints and I found the same tones at his hot yellow red heavy, nude toned print at my old Summitar prints.

It was 15 years ago , I went a cafe with illuminated with too many transparent glass hot filament GE bulbs and took some women pictures on Konica and print on Fuji with Kodak Lab.

And they were same tones plus lots of skin microscopic details plus green vains and lots of black noise gives the muscles out of print with 3D local light shadow plays.

Is thorium responsible about this success ?

Thank you ,

Mustafa Umut Sarac

Istanbul

 

[robklurfield]

Don't try this at home. I think chris101 can expose film just by smiling at it and using his teeth as a light source. But seriously, Chris has some very cool images with the uranium and he actually knows how to do it without poisoning himself.

 

[Roger Hicks]

Dear Mustafa,

Uranium toning is like any other toning, i.e. it gives a different image colour to a black and white print. Thorium in lenses is another matter entirely.

Sorry to give such a serious answer to a light-hearted question but you never know what some people will accept as the eternal truth because they read it on the internet!

Cheers,

R.

 

[rxmd]

Maybe this, after all, is the secred of the famed leica Glow 🙂

 

[Chris101]

Oh man! You should see me in the Tyvek moon-suit I wear when I work with heavy metal salts in a photo tray! The hazard associated with uranium, vanadium and other heavy metals is liver and kidney damage, not the extremely slight radioactivity the depleted uranium nitrate has. While the pure compound does click a geiger counter nicely, the prints do not register anything at all above the background radiation.

 

[sevo]

Uranium toning is like any other toning, i.e. it gives a different image colour to a black and white print. Thorium in lenses is another matter entirely.

Besides, uranium toning is used because uranium pigments have a unique variety of very vivid colours - there is no other inorganic toner that does a extended yellow range stretching from green to pink. Thorium has no such range, indeed it has no particular merits as an inorganic pigment - at the very best it might deliver some kind of weak blue. But there is no point in that, there are plenty of other metal ions that deliver better blues and are much less poisonous and more stable.

 

[Roger Hicks]

Oh man! You should see me in the Tyvek moon-suit I wear when I work with heavy metal salts in a photo tray! The hazard associated with uranium, vanadium and other heavy metals is liver and kidney damage, not the extremely slight radioactivity the depleted uranium nitrate has. While the pure compound does click a geiger counter nicely, the prints do not register anything at all above the background radiation.

Dear Chris,

Purely as a matter of interest, how much uranium do you have to get into your body, and how is it normally absorbed (skin, ingestion by mouth, powder inhalation, etc)? I'm reasonably familiar with how heavy metals work as poisons, but I have no idea whatsoever about dangerous doses.

Have you ever tried mercury toning? Old books speak of the 'engraving black' of the image. I've always idly wanted to try, but not enough to want to mess around with mercury salts.

Cheers,

R.

 

[maddoc]

How do these heavy metal toner change their color in the toning process ? Different oxidtion states of cations or cationic complex compounds ? If yes, anybody tried Ru ?

 

[Chris101]

Hi Roger,

According to Energy Department studies on uranium workers, uranium hazards are twofold: radiological and toxicity. For depleted uranium (as U-238), an ingested dose above 183 milligrams per annum is considered to cause cancer. Toxicity is divided between ingestion and inhalation - it is not appreciable absorbed through the skin. Amounts above 45 micrograms per annum are considered hazardous, and single doses above 17mg have an acute effect on the kidneys.

These are very small amounts, thus I use nitrile gloves, a disposable tyvek jumpsuit (with hoodie), goggles and a particulate filter in a side vented respirator while working over the trays. Once the prints have been washed and partially dried - and the area cleaned up - I use gloves alone. When they are completely dried, I handle them as little as possible and wash after doing so.

By my quick calculations, a single 11x14 print contains 40mg or less of uranium.

 

[Chris101]

... Have you ever tried mercury toning? Old books speak of the 'engraving black' of the image. I've always idly wanted to try, but not enough to want to mess around with mercury salts. ...

No. I AM considering trying mercury sensitization of Efke infrared film though. I have a dark glass desiccator that I will place a pool of Hg in the bottom of, and then just put the cassettes of film on the rack just above the liquid. I'll leave them in the closed jar for a week, and then shoot them experimentally to determine the iso boost. If I can get a 5x increase, I will be very happy!

This however involves metallic mercury, which is the least hazardous form of the element. I just got the last experiment involving mercuric chloride out of our laboratory curriculum, so I don't especially want to mess with those salts either.

 

[Roger Hicks]

Dear Chris,

Thanks very much for the detailed answers. It is always intriguing to compare modern recommendations with the sometimes terrifying risks our forebears took for granted. I think I recall a report in the BJP of a chemist's (US: druggist's) assistant biting a cyanide crystal in half!

Read the reports on mercuric chloride toning at your peril: it really does sound interesting...

I look forward to your results with mercury sensitzation.

Cheers,

R.

 

[Chris101]

How do these heavy metal toner change their color in the toning process ? Different oxidtion states of cations or cationic complex compounds ? If yes, anybody tried Ru ?

Hey Gabor,

Different toning processes have different mechanisms. I have not studied the mechanisms involved, but a clue may lie in the solubility of uranium, vanadium and iron toner in basic solutions. Ruthium may work similarly to iron, but the size of the atom would undoubtedly have an effect.

 

[semilog]

Those of you with a fascination for chemistry that is simultaneously interesting and dangerous will want to read the chemist Derek Lowe's wonderful series of articles, Things I Won't Work With. A sample:

And yes, what happens next is just what you think happens: you run a mixture of oxygen and fluorine through a 700-degree-heating block. "Oh, no you don't," is the common reaction of most chemists to that proposal, ". . .not unless I'm at least a mile away, two miles if I'm downwind." This, folks, is the bracingly direct route to preparing dioxygen difluoride, often referred to in the literature by its evocative formula of FOOF.

 

[Chris101]

What a cool blog that is! Fluorine scares me just straight out of the bottle. They say there are good fluorine chemists, but no old fluorine chemists.