Boost film-speed with simple reversal process?

[richard ide]

With the association to Itek, I wonder if this may have been used for reversal materials. Itek catered to the printing trade and this would be very important to them. I used a large quantity of various types of reversal materials for reproducing mainly very high contrast originals like engineering drawings and photographic line film. A few products reversed actinically but I think the other emulsions must have been designed for solarization to reverse the image. I first played with these around 1968 and remember some developers would not give a clean reversal. In the 1980's the products were much improved but using the film in a process camera, it was necessary to underexpose giving a bit of base density to retain details in drawings. Bleach would clean up the background without losing detail if you were careful.

 

[Nicholas Lindan]

The article in Haist mentions a 1890 account of achieving reversal using thiourea compounds, thiourea being urea with sulfur where the oxygen should be. As onions have a lot of pungent sulfur compounds, the same general reaction may have been the basis for the "Shallot Reversal Process":
(there was a url link here which no longer exists)

Although the Howell formula under discussion is described as "successfully used with higher speed films," it seems most of the activity with reversal monobaths was for processing microfilm and lithography film. May the reference have been to "high speed" Kodalith?

 

[Photo Engineer]

Paul Gilman's method was presented at the ICIS meeting in 2006 and is published in their journal. He showed real photographs which were projected transparencies. Kodak never investigated this process and little is known about the mechanism. A long thread is published here about it. Kodak rejected all solicitations to continue this work or to produce a trial run. So, the matter is dropped. AFAIK, there is a patent on this as well.

Grant Haist moved on from monobath processes himself to develop "Bimat" used in space photography, and also to develop several thermally processed materials. He taught me how to coat them and I produced several examples myself using his method and similar methods. They produced negative images of normal speed though.

PE

 

[Athiril]

Paul Gilman's method was presented at the ICIS meeting in 2006 and is published in their journal. He showed real photographs which were projected transparencies. Kodak never investigated this process and little is known about the mechanism. A long thread is published here about it. Kodak rejected all solicitations to continue this work or to produce a trial run. So, the matter is dropped. AFAIK, there is a patent on this as well.

Grant Haist moved on from monobath processes himself to develop "Bimat" used in space photography, and also to develop several thermally processed materials. He taught me how to coat them and I produced several examples myself using his method and similar methods. They produced negative images of normal speed though.

PE

If this could sensitise an otherwise ISO 400 speed film up to 25,600, wouldn't the same idea be able to applied to a ridiculously fine grain film.. such as on the level of Tech Pan or Vision Print etc, and give them much faster speed? Like 50D movie film @ 3200 ISO. ISO 25 films @ ISO 1600?

 

[Photo Engineer]

I cannot say as the experiments were never carried out.

PE

 

[Athiril]

I just read through the CIS 2006 thread you posted, and I have to agree with r-s. At least from your description of the way things were handled with it. The market 'research' was really poor/next to non-existent.

 

[albada]

I just read through the CIS 2006 thread you posted, and I have to agree with r-s. At least from your description of the way things were handled with it. The market 'research' was really poor/next to non-existent.

Can you post a link to that CIS 2006 thread? My searches are coming up dry.

Thanks,

Mark Overton

 

[Athiril]

I'm up to page 11 currently.
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Related threads and threads of similar interest
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^--- this last one has example image from the film at ISO 12000 and 24000

 

[albada]

(there was a url link here which no longer exists)
^--- this last one has example image from the film at ISO 12000 and 24000

Wow! A true 24000 film. But from reading some of those posts, it seems unlikely that Kodak will put this film into production. Most unfortunate.

Mark Overton

 

[Athiril]

Probably not. My immediate thoughts are this requires all new infrastructure (processing) to support just for this specific film. Which is a really big obstacle to overcome I would think.

Plus it sounded like the cost (incl wages) of making the film didn't leave enough room for a return, or exceeded a projected selling price.

And it appeared to me no market research was carried out, just assumptions. To the extent they grossly misjudged who the target customers were going to be.




Doubt it'll be heard from again. Unless someone wants to reconstruct it from the patents. But PE said he couldn't get two of the chemicals required. So that's another hurdle.

 

[removed account4]

years ago i read ( here ? ) that you could boos film speed
by fuming the film over ammonia or peroxide (?) or something simple and "household"
it has nothing do do with monobaths ... and might work with paper as well as film ...

any idea what this is i am talking about ?

thanks
john

 

[Oxleyroad]

years ago i read ( here ? ) that you could boos film speed
by fuming the film over ammonia or peroxide (?) or something simple and "household"
it has nothing do do with monobaths ... and might work with paper as well as film ...

any idea what this is i am talking about ?

thanks
john

Mercury... ?

 

[removed account4]

hi oxleyroad
nope
i found a thread that mentions it ( not the thread i was referring to though )
it was something mentioned in photo techniques magazine
and it has to do with fuming exposed film in hydrogen peroxide heated to about 100ºF ...


(there was a url link here which no longer exists)