Edible Film Developers

[Andrew O'Neill]

I'd make some dark chocolate carbon transfer prints and lick them like candy... if it wasn't for the di chromate that could still be lingering about!

 

[DarkroomExperimente]

trying to remember where I first heard about glucic acid....this was one of the first things I found..from 1882

https://books.google.com/books?id=U...=onepage&q=glucic acid film developer&f=false

...takes a long time to find the relevant part...but they give some hints on extracting the pure glucic acid from solutions...

 

[DarkroomExperimente]

I'd make some dark chocolate carbon transfer prints and lick them like candy... if it wasn't for the di chromate that could still be lingering about!

I did get a very thick goopy cocoa developer to work...very faint images & there was a chocolate tint to the negative

 

[Andrew O'Neill]

 

[BAC1967]

thanks...

one other puzzle...when I tested pineapple juice ( sugar content a bit less than the honey developer, but close ) it worked great... but the second time I tried it..a few days later after it was opened & refrigerated...it was very weak...wondering why that is...gonna have to get that figured out since I promised a friend I would develop her Hawaiian photos with a pineapple developer...perhaps I always need to use fresh juice...but would be nice to understand why

You can use coconut water. This recipe needs to be refined but it did work.

Pure Coconut Water (I used Vita Coco brand) - 500mL
Washing Soda - 20g
Vitamin C - 8g
Develop at 20 degrees C for 15 minutes. 30 seconds of agitation at start and 15 seconds for every minute after that.

Coconal Test by Bryan Chernick, on Flickr

 

[DarkroomExperimente]

it seems "glucic acid" might be an old obsolete name

found old books discussing how heated glucic acid solutions turn brown ( mine did ) and generate "apoglucic acid"

obviously with honey there must be a million things happening...one thing mentioned was the formation of "humic acids" which look like huge molecules with phenolic-ish parts

even with pure sugar I'm sure all kinds of things can happen

might have to get some more pure glucose & fructose and see how they compare to honey

also..read something about "apoglucic acid" precipitating from a basic solution when acid is added...gonna try that

 

[DarkroomExperimente]

You can use coconut water. This recipe needs to be refined but it did work.

Pure Coconut Water (I used Vita Coco brand) - 500mL
Washing Soda - 20g
Vitamin C - 8g
Develop at 20 degrees C for 15 minutes. 30 seconds of agitation at start and 15 seconds for every minute after that.

Coconal Test by Bryan Chernick, on Flickr

have you tested it without the vitamin C ?

 

[BAC1967]

have you tested it without the vitamin C ?

No, I only ran the one test to see if it would work. I was only trying to answer the question that has stumped the scientific community for decades: How did the castaways develop the film in the Gilligan's Island episode Castaway Pictures Presents? Now that I know I don't see a need to run anymore tests.

http://gilligan.wikia.com/wiki/Castaways_Pictures_Presents

 

[DarkroomExperimente]

interesting....a lot of the old sources refer to a different formula for glucic acid than what wikipedia describes...

they also use the word "atom" the way we'd use "molecule"...

 

[Alan Johnson]

http://www.ausetute.com.au/redsugar.html
When the sugar ring is opened long chain reducing sugars are first formed,IDK if they may meet the Kendall-Pelz specification for developers.

 

[DarkroomExperimente]

http://www.ausetute.com.au/redsugar.html
When the sugar ring is opened long chain reducing sugars are first formed,IDK if they may meet the Kendall-Pelz specification for developers.

Thanks!!

 

[DarkroomExperimente]

I think I solved one mystery....the reason the second test of pineapple dev was so weak is that since it had been refrigerated it just didn't get as hot as the first batch & so didn't generate as much developer

 

[MartinP]

You can use coconut water. This recipe needs to be refined but it did work.

Pure Coconut Water (I used Vita Coco brand) - 500mL
Washing Soda - 20g
Vitamin C - 8g
Develop at 20 degrees C for 15 minutes. 30 seconds of agitation at start and 15 seconds for every minute after that.

My apologies for my (lack of) american language skills again. Is "coconut water" the liquid from inside coconuts?
(In british english, usually called coconut-milk).

 

[NedL]

My apologies for my (lack of) american language skills again. Is "coconut water" the liquid from inside coconuts?
(In british english, usually called coconut-milk).

Yes, it is the clear liquid inside the coconut. As opposed to "coconut milk" which is made by grating and then squeezing the white coconut "meat".

 

[BAC1967]

My apologies for my (lack of) american language skills again. Is "coconut water" the liquid from inside coconuts?
(In british english, usually called coconut-milk).

Yes, it's the liquid from inside the coconut. Some people call it the coconut milk. It's very refreshing after you've been hiking in the jungle on a South Pacific island. Here in the U.S. you can buy it in the grocery store.

 

[NedL]

I have been thinking of trying to preserve a sensitized calotype using oxymel, which is made by adding acid to honey. Oxymel was used as a preservative for collodion plates. A preservative that was successfully used with calotypes was a mixture of dextrin and tannic acid, and since honey contains "honey dextrin", I thought it might be worth a try. "Honey dextrin" is not dextrin, but a complicated mixture of saccharides and complex sugars.

Honey and/or various sugars are occasionally mentioned as calotype ingredients. I always thought it might be for preservative value, but this thread is making me wonder if it might have other effects, like making the calotype more sensitive, or interacting somehow with development. Probably not, since the process is all acidic.... but still, I wonder.

So...maybe you could add vinegar to honey to preserve them, then add carbonate to honey to develop them!

 

[MartinP]

Yes, it is the clear liquid inside the coconut. As opposed to "coconut milk" which is made by grating and then squeezing the white coconut "meat".

Thank you for the explanation. Thanks too, to BAC1967 who posted just a few seconds later!

 

[Truzi]

My apologies for my (lack of) american language skills again. Is "coconut water" the liquid from inside coconuts?
(In british english, usually called coconut-milk).

I always called the liquid from inside coconut-milk (I'm in the U.S.). As others point out, the "water" is more of a different process - and I prefer the milk to water. To me, the "water" is akin to the proverbial blood from a turnip, if you catch my drift.

 

[DarkroomExperimente]

PROGRESS!!!!

this link: https://books.google.com/books?id=e...AJ#v=onepage&q=heating glucose alkali&f=false

on page 157 it says that when sugar is heated with copper oxide it forms "glucique acid" C12H18O9 ( not the same as glucic acid on wikipedia )...that acid breaks down into pyrocatechinol & gluconic acid...and the gluconic acid then breaks down into glyceric acid and lactic acid...THEN the glyceric acid turns into lactic acid and oxalic acid

THEN the pyrocatechinol reacts with the lactic acid which forms two esters of hydrocaffeic acid

Now...they were using copper oxide as a catalyst...I'm not...and they seemed to be using potassium hydroxide...I'm not

but...at least it seems to show that could be a lot more going on here....and perhaps not using a catalyst & using a weaker base isn't a huge issue (?)

...the funny thing is..I haven't bothered doing anything with Caffenol because so many other people are already doing it...and now maybe I ended up making one of its ingredients anyway

so...is "pyrocatechinol" an old name for pyrocatechol ??????

 

[Alan Johnson]

https://books.google.co.uk/books?id=I3gC0bX_IKAC&pg=PA31&lpg=PA31&dq=reducing+sugar+alkali+reaction&source=bl&ots=CpCNBKiI4a&sig=UbFTgTcJOoYphKrDKwvzImr3zFA&hl=en&sa=X&ved=0ahUKEwjLw9C0vY7NAhWKKMAKHXtHBBUQ6AEINTAE#v=onepage&q=reducing sugar alkali reaction&f=false
$9 "All the sugars that contain free sugar group undergo enolisation and various other changes when placed in alkaline solution. The enediol forms of sugars are highly reactive....As a consequence they readily reduce oxidising ions such as Ag+ ....."
This appears to be what DE has found, for the first time in relation to film developers.

 

[DarkroomExperimente]

https://books.google.co.uk/books?id=I3gC0bX_IKAC&pg=PA31&lpg=PA31&dq=reducing+sugar+alkali+reaction&source=bl&ots=CpCNBKiI4a&sig=UbFTgTcJOoYphKrDKwvzImr3zFA&hl=en&sa=X&ved=0ahUKEwjLw9C0vY7NAhWKKMAKHXtHBBUQ6AEINTAE#v=onepage&q=reducing sugar alkali reaction&f=false
$9 "All the sugars that contain free sugar group undergo enolisation and various other changes when placed in alkaline solution. The enediol forms of sugars are highly reactive....As a consequence they readily reduce oxidising ions such as Ag+ ....."
This appears to be what DE has found, for the first time in relation to film developers.

thanks!

 

[Rudeofus]

The enediol forms of sugars are highly reactive....As a consequence they readily reduce oxidising ions such as Ag+ ....."

Reduction of Ag+ is necessary but not sufficient: in order to be counted as photographic developer, a compound needs to selectively develop silver only in those locations where metallic silver is already present. Since enediol forms follow the Kendall/Pelz form, there is a high chance that these enediol forms act as real photographic developers.

 

[Alan Johnson]

I have confirmed in a test that ordinary granulated sugar does not provide a developer, this is because it is sucrose which is not a reducing sugar.
It might be possible to convert granulated sugar to reducing sugar by boiling it with acid:
http://www.mrothery.co.uk/module1/Mod 1 techniques.htm

 

[DarkroomExperimente]

I have confirmed in a test that ordinary granulated sugar does not provide a developer, this is because it is sucrose which is not a reducing sugar.
It might be possible to convert granulated sugar to reducing sugar by boiling it with acid:
http://www.mrothery.co.uk/module1/Mod 1 techniques.htm

Exactly what I experienced.....after heating sucrose in the microwave with vinegar I was able to develop film the same way as I have with dextrose/glucose, fructose, and honey....but if sucrose wasn't first heated with vinegar it did not work as a developer

 

[NedL]

DE - to recap, you have heated dextrose/glucose, fructose, and honey, with sodium carbonate, and made developers. For sucrose, you heated it with vinegar... and after that did you add an alkali?