In camera Alternative Processes ????

brucej · Dec 25, 2007

In camera Alternative Processes ????

When I first started researching “Alternative Photographic Processes” a while ago,
The words Alternative Photographic Processes means to me that the process is Non-silver and starts by Exposing a plate or coated paper in a camera,
Developing it
And THEN printing it or making the negative a positive.

But with most of the stuff on the net and most of the books I have seen
The words Alternative Processes means
“Alternative PRINTING” with an already made negative.

Is anybody actually doing the entire non-silver process in a camera and if so which process are you using?
Thanks

Photo Engineer · Dec 25, 2007

Cuprous Oxide is light sensitive and quite fast. It is outlined in several texts on light sensitive systems. The nice thing is that it is almost orthochromatic in nature due to the color.

PE

Vaughn · Dec 25, 2007

Terry King, the Historian for the Royal Photography Society has discovered, or re-discovered a cyanotype process that can be used in-camera. He calls it Cyanotype Rex. He described it generally in ViewCamera Magazine awhile back. One must buy his dvd to get the details.

Basically, one coats the paper with Ferric oxalate (or others have used Ferric ammonium citrate, I believe). Then it is exposed, then developed in a bath of Potassium ferricyanide.

Just a thought, but I wonder if one could incorparate the Ferric oxalate into gelatin, coat glass with it, then develop in the Potassiun ferricyanide to yield a blue and white negative for printing. If there is a toner for cyanotypes that yields a yellowish negative, then the negatives could be toned and used for other UV-exposed alt processes.

Vaughn

Photo Engineer · Dec 25, 2007

The problem with most alternative processes is that they are UV sensitive, not visible light sensitive and therefore distort what the human eye would see. If this is what you want, then that is fine, but if not, then it presents a problem.

PE

Brook · Dec 25, 2007

Kind of makes silver the natural choice eh?

gr82bart · Dec 25, 2007

I started another thread on Robb Kendrick who makes 8x10 tintypes from plates in camera and then processes them in his 'portable' darkroom. Several others do wet/dry plates in camera too. Do a search here to find them.

Regards, Art.

Brook · Dec 25, 2007

Tintypes, a type of wetplate collodion, is based on silver nitrate. A direct positive is possible, as is a negative that can be tailored to most any type of store bought silver paper, or the various alt processes.

brucej · Dec 25, 2007

"Basically, it was cuprous oxide precipitated in the dark in a peptizing polymer and then coated. Exposure was normal (blue + uv light) and development was done with sulfuric acid at about 0.1 N. The image could be fixed with sodium hypo."

PE back in 2005 you wrote this in another thread, do you mean red cuprous oxide ?

Photo Engineer · Dec 26, 2007

Yes, red cuprous oxide. But you have to make it in-situ. The reason is that the material you buy off the shelf is already 'fogged'. When it is made fresh, it is a much lighter yellow red.

There are a number of patents and research disclosures on this. I don't have any of the numbers though, sorry. I think that the original work was by Peter Hillson or Hillison at Kodak in the 60s. I've forgotten the spelling. Sorry.

PE

gr82bart · Dec 26, 2007

Brook said:
Tintypes, a type of wetplate collodion, is based on silver nitrate. A direct positive is possible, as is a negative that can be tailored to most any type of store bought silver paper, or the various alt processes.

D'oh! You're right. My bad. Hmmm ... it doesn't really leave much left, now does it?

Regards, Art.

kevin klein · Dec 26, 2007

I always thaught that "In Camera" meant exposing and development in side the camera.

brucej · Dec 26, 2007

KK i guess you are right there, i will try and change the thread name.

PE doing a bit of searching i have found that cuporous oxide is indeed light sensitive, you can make a solar cell by heating a copper plate and making a layer of cu2o , and you can make it by Electrolysis useing salt water and copper ELECTRODES, and use the left over salt water as weed killer.

So from what you are saying it needs to made in the dark, and kept in the dark and should be yellow.
How were you useing it ? as it appears to be water insoluble

Photo Engineer · Dec 26, 2007

Bruce;

It is made in a polymer and then coated on support such as film or paper. On exposure and development, you get a copper metal negative image and a cuprous oxide positive image. The cuprous oxide can be dissolved. The speed is similar to Kodabromide paper.

If you precipitate it without a polymer to protect it, the crystals will clump and become useless.

PE

brucej · Dec 26, 2007

Thanks PE
your comments makes it a fair bit more complex to do this process.
more thinking time

Photo Engineer · Dec 26, 2007

Try the textbook by Khosar on alternate processes. I don't remember the title, but I found it very interesting.

PE

In camera Alternative Processes ????

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