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-   Alternate printing processes (http://www.film-and-darkroom-user.org.uk/forum/forumdisplay.php?f=38)
-   -   reversal prints (http://www.film-and-darkroom-user.org.uk/forum/showthread.php?t=13536)

big paul 1st December 2020 05:09 PM

reversal prints
 
I have got my MPP camera out all set for tomorrow ,and filled 5 film holders with 10 sheets of Ilford RC paper and have my citric acid and peroxide ready to do some reversal prints tomorrow ,turning paper negatives in to positives .. I have never done this before ,so it should be fun ,I may even try colour next year .has anybody tried this prosses ..

JOReynolds 2nd December 2020 12:10 AM

reversal colour prints
 
It's much easier to reversal-process colour paper because all of the silver is bleached out, leaving only a dye image. In B&W, the desired image is contained in the silver produced in the second development, so you have to be careful not to bleach it out earlier in the sequence.

Once upon a time there was an Eastman Product processed in R100 chemistry. It wasn't very good, although it was better than the Ansco equivalent of the era. Then Kodak-Pathé Chalon-sur-Saône (France) came up with Ektachrome paper, vastly better and processed in four-bath R14. It was a replenished system and had a smelly acetic acid stop bath. Then came R3, a version with a water wash in place of the stop bath. There was a paper version with adjusted contrast for making copy prints, which you could use for photography in a large-format camera and loads of light. The water bath needed to start with an egg-cupfull of first developer in it to correct slightly pink highlights.

One weekend a colleague's processor was up to temperature and waiting for something or other to arrive and he tried making reversal prints with ordinary Ektacolor neg/pos paper. The results were way off at first and needed huge filter settings - but were promising. I don't have facilities for tests, so I'm not volunteering to start experimenting again but the fundamentals were sound.

In theory it only needs a straight PQ first developer, a stop bath [lights on from here], a stannous fogging bath or re-exposure and a rinse, some RA4 colour developer, RA4 bleachfix and wash.

There might be a contrast problem. Ektachrome paper was intended to make prints from transparencies (contrast gamma typically ~1.5) and if the paper contrast is 1.0 the prints will be way too contrasty, like Cibachrome.

big paul 3rd December 2020 02:24 PM

2 Attachment(s)
Well it all went %$*! up ,a complete disaster ,I know what the problem Is ,the Hydrogen Peroxide I was using Is to week ,It is food grade and should have been hair type Peroxide ,that Is a lot stronger ,I got my paper speed right ,so my negative print was OK but the Peroxide was not strong enough to clear the image ..



Attachment 3934

Attachment 3935

Terry S 3rd December 2020 02:43 PM

Paul, if you haven't seen this thread and main links, that I found to be very useful, it's well worth checking them out. There are only 7 posts, with mine with the links being number 7 (at the moment anyway):

http://www.film-and-darkroom-user.or...ght=van+cleave

Both b/w and colour simple-ish reversal is shown in the videos.

!!!!!Anyone looking at doing it though should listen to the guys bits about being careful when doing it, especially if you are using as he does, 35% Hydrogen Peroxide. Be safe and have fun is the bottom line.

Hopefully when summer comes again, it's something that I'd like to check out.

And Paul, don't forget to let us all know how you get on! :)

Terry S

PS You've just made a post as I was writing Paul. :)

A good first effort, but yes, as mentioned in the video, you do need a strong strength of Hydrogen Peroxide. It's widely available on Ebay UK btw.

big paul 3rd December 2020 04:22 PM

Hi Terry I have been looking on Ebay but cannot find anything stronger than 12% and it all says food grade the hair stuff has cream in it ,so when I get my jabs I will go to where my wife has her hair cut and see if she can get me some of the strong stuff .its great that with film photography there are loads of ways we can make an image ,I have been successesfull with the X-ray film and will be glad to start getting out and shooting some more of that ..

Terry S 4th December 2020 02:35 PM

Quote:

Originally Posted by big paul (Post 137094)
Hi Terry I have been looking on Ebay but cannot find anything stronger than 12%....

Paul, I've just re-watched the video link below, and he says that he starts out with 30% HP, but then dilutes it down to 9%.

If you watch the video at 10 minutes onwards, he says that the minimum strength you should use is 9% hydrogen peroxide and I wouldn't try using hairdressing HP cream, which will have all sorts of other chemicals in it which will interfere with the process. You need the pure stuff.

Having just checked Ebay UK, I found it is widely available at various prices and amounts at this strength. And even though it's not 30%, he recommends keeping in the fridge when not in use.

The whole video is well worth watching as he explains it all in simple terms, which is good for those like myself, who have never done it before.

https://www.youtube.com/watch?v=-PFQXaDdl60&t=650s

Terry S

big paul 4th December 2020 03:53 PM

Hi Terry I think you have the wrong end of the stick ,I know that I cannot use Hydrogen Peroxide with cream in it .all the stuff they sell on ebay and amazon are food grade ,it can be used on food and used for teeth and gum problems so it is not the same and not very strong ,its got to be at lest V40 and minimum 12% ,and the stronger the better ,so it has to be type that bleaches hair ,I have found someone who sells it ,but I am not in a hurry at the moment ,as I have said the one that I bought and the one I need are two different strengths .Hope that's helped .:D


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