Slice of Radioactive Thorium Mineral Rock as Light Source for Contact Print

[Mustafa Umut Sarac]

I read at APUG that film is superior to digital because film records everything with molecular level. I dont know how much of these molecules records the photograph but I developed an idea.

As Lithography , higher the frequency of light source , better the resolution.

I thought I can find a radioactive source for experiment. Turkey have %80 of Thorium reserves of the world and I can order a mineral rock from geology shop and than order a thin slice , may be 6x9 or 4x5.

And than put the thin slice on film - paper layers.

Do you think I can print a higher resolution result or gamma radiation makes irregular noise on the paper ?

Mustafa Umut Sarac
Istanbul

[dsphotog]

Probably easier to get than Durst enlarger lamps....

[vinny]

Yes.

[Dirk Rösler]

Worth a try but may not work. "Natural thorium is essentially monoisotopic 232Th, which is the longest-lived and most stable isotope of thorium, having a half-life comparable to the age of the universe. " (Wikipedia). The long half-life suggest extremely low radiation.

Secondly, if it emits alpha rays, they will not penetrate the film material to reach the paper. AFAIK alpha radiation is easily blocked by paper, skin etc. If it is gamma radiation, it may penetrate all film areas, no matter if developed (highlights) or clear, thus resulting in a blank, white image.

[ShannonG]

Sounds like a fun experiment,ive thought about trying alternative light sources as well. Such as bio luminescence using fire fly's.besides bio luminescence ,static electricity might be cool,sparklers and glow sticks. Of course the quality would be diminished but it would be a fun art project

[Dan Fromm]

Interesting question. Why don't you do the experiment? And while you're at it, contact print the same negative using y'r piece of rock as a source and using visible light and compare the prints. I'm not sure you'll get results that can be told apart with the naked eye.

Dirk, 232Th is an alpha emitter but some of the daughters in the decay chain are gamma emitters. See, e.g., http://home.earthlink.net/~michaelbr...aeroektar.html

[Jmarmck]

If it is gamma radiation, it may penetrate all film areas, no matter if developed (highlights) or clear, thus resulting in a blank, white image.

Yup.

[Arne Croell]

Secondly, if it emits alpha rays, they will not penetrate the film material to reach the paper. AFAIK alpha radiation is easily blocked by paper, skin etc. If it is gamma radiation, it may penetrate all film areas, no matter if developed (highlights) or clear, thus resulting in a blank, white image.

Thorium just emits alpha rays, yes, but the secondary elements in the decay chain on its way to 208Pb (lead) are also beta and gamma emitters - for that reason the older thoriated glasses like Apo-Lanthars or Repro-Clarons have measurable gamma activity.

[Kevin Crisp]

You could closely pack a bunch of R claron lenses.....

[Arne Croell]

I read at APUG that film is superior to digital because film records everything with molecular level. I dont know how much of these molecules records the photograph but I developed an idea.

As Lithography , higher the frequency of light source , better the resolution.

I thought I can find a radioactive source for experiment. Turkey have %80 of Thorium reserves of the world and I can order a mineral rock from geology shop and than order a thin slice , may be 6x9 or 4x5.

And than put the thin slice on film - paper layers.

Do you think I can print a higher resolution result or gamma radiation makes irregular noise on the paper ?

Mustafa Umut Sarac
Istanbul

Ok, that "molecular level" argument makes me wince. Yes, the latent image formation is based on the reaction of silver halide molecules, but by the same line of thought I could argue that digital is working on an "electronic level", since its based on electrons being moved from the valence band to the conduction band in the semiconductor (actually, the silver halide reaction starts out basically the same way), and electrons are certainly smaller than atoms or molecules, right? ;-)

In the case of film and paper, each of the silver halide crystals in the emulsion that got at least 4 molecules out of the billions/trillions in it changed by the action of light, will be fully transformed to silver in development. The size of the silver filament depends on the original crystal size as well as on the specific mechanism of silver formation (aka development), but it consist of nearly as many silver atoms as the original crystal had silver halide molecules, and not on how many molecules in that crystal got changed by the light action. For digital capture, the sensor resolution is defined by the size of those little photo transistors, regardless (mostly) of how many electrons were involved. Its not that much of a difference on the basic level.

That being said, one can certainly get higher resolutions than digital with special film emulsions, like so-called Lippmann emulsions, with resolutions well below 1 micron. So if you would place your thin section sample* (without cover glass!) in good contact with a nuclear plate or an emulsion for holographic images, you might get a higher resolution of the structures.


*side note: producing thin sections of radioactive rocks needs to be done with caution. Dust containing alpha emitters getting inhaled or ingested is very dangerous, plus the lapping and polishing slurries will become nuclear waste.