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Dissolving Exposed 16mm Reversal


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#1 M Joel W

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Posted 07 December 2006 - 07:48 PM

I want to dissolve some of the emulsion from 16mm reversal stock (200ISO B/W Kodak) so that it looks totally transparent. I want to do this over the course of a foot or two to create a "fade in from white" look for a flashback sequence, but with rough edges. The film is already exposed so I can't rack aperture, and it's reversal so I can't do it in lab. Any tips? What dissolves the emulsion but not the base and can then be neutralized so it doesn't destroy the entire film?
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#2 Charles MacDonald

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Posted 07 December 2006 - 08:43 PM

I want to dissolve some of the emulsion from 16mm reversal stock (200ISO B/W Kodak) so that it looks totally transparent. I want to do this over the course of a foot or two to create a "fade in from white" look for a flashback sequence, but with rough edges...
Any tips?


Well you could try "farmers reducer" Named after a dude named farmer i belive.. But that will give a smooth fade to clear without actua;;y afecting the gelitan. There was an old formula that ILFORD used to have for an etching reducer (simalar to what one might use to make a technicolour matrix) but I am not sure where to find the formual.

Farmers is just Ferocyanide and fixer, so it is simple safe and effective. You do have to re-wash the film.
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#3 Clive Tobin

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Posted 07 December 2006 - 09:01 PM

I want to dissolve some of the emulsion from 16mm ...


As I rediscovered by accident, ordinary household bleach will totally dissolve the film gelatin emulsion and the images in it.

If it is well diluted you could dip say a foot of film into it, pushing it in one frame at a time ending at the framelines, and get a gradual disappearance as projected. Have some fresh water handy to toss the film into stop the process after it has gone far enough. Practice on some film you don't care about first.
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#4 Dominic Case

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Posted 07 December 2006 - 10:47 PM

I want to dissolve some of the emulsion from 16mm reversal stock (200ISO B/W Kodak) so that it looks totally transparent.

I think you just need to "bleach" the image, not dissolve the emulsion - which would be rather messy and gluggy).

As a previous poster said, you can do this with Farmers reducer, which is a combination of the potassium ferrocyanide used in the reversal (or colour neg/pos) bleach bath, and fixer. The ferro converts the silver image back to silver bromide, which is dissolved by the fixer (sodiumn or ammonium thiosulphate).

To get the fade to white effect, I guess you would need to gradually dip the length of film into the solution, so that the first bit you dip will be immersed for a minute or two, but the last bit will only just get wet - and then you would whip it out and into a water wash to arrest the action. You'd need to practice several times on unwanted shots.

A book or site on b/w stills processing (try googling farmers reducer) will give you the info about the bleach/fix chemicals, concentration etc you need. The rest is up to you to try out.
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#5 Clive Tobin

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Posted 10 December 2006 - 08:01 PM

I think you just need to "bleach" the image, not dissolve the emulsion - which would be rather messy and gluggy)...


No it's not. The emulsion just slowly and evenly disappears into solution with no mess. At least with the Tri-X Reversal that I did it on.
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#6 James Erd

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Posted 11 December 2006 - 01:00 AM

Farmers is just Ferocyanide and fixer, so it is simple safe and effective. You do have to re-wash the film.


It's not as bad as toning with Polonium 210 :ph34r: but Farmers reducer is a fairly nasty concoction ;)
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#7 Bernhard Zitz

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Posted 11 December 2006 - 06:30 AM

I want to dissolve some of the emulsion from 16mm reversal stock (200ISO B/W Kodak) so that it looks totally transparent. I want to do this over the course of a foot or two to create a "fade in from white" look for a flashback sequence, but with rough edges. The film is already exposed so I can't rack aperture, and it's reversal so I can't do it in lab. Any tips? What dissolves the emulsion but not the base and can then be neutralized so it doesn't destroy the entire film?


I did this with a little piece of cotton and Eau de Javel rubbing Kodachrome S8, first the magenta comes off and you have the greens and blues left after that it gets transparent... I don't know if it hurts the film since Eau de Javel is a little erosive...

Edited by Bernhard Zitz, 11 December 2006 - 06:34 AM.

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#8 Mark Dunn

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Posted 11 December 2006 - 11:46 AM

Farmer's is really meant for thinning negatives, or just taking a bit of density off a paper print. Used concentrated and excessively it tends to stain yellow.
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#9 Charles MacDonald

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Posted 11 December 2006 - 08:26 PM

It's not as bad as toning with Polonium 210 :ph34r: but Farmers reducer is a fairly nasty concoction ;)

Don't know how Polonium 210 would work for toning, I know that it is restricted here in Canada, which makes it hard to buy a "staicmaster brush". (it is the sorce those brushes use to disapate static charges. The 186 day half life meansyou have to repelce the cartridge every couple of years.

AFAIK, both ingredents in Farmers reducer have medicinal uses. It is only posible to get cynaide gas by using STRONG acid with it.
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#10 Bernhard Zitz

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Posted 12 December 2006 - 06:07 AM

As I rediscovered by accident, ordinary household bleach will totally dissolve the film gelatin emulsion and the images in it.


The good old language barrier: household bleach is called "Eau de Javel" in french :D :D :D

The main problem would be to get a smooth fade. I you use "Eau de Javel" that's 2.6% sodium-hypochlorite (NaClO) and rub off the emulsion as I discribet before, you'll get it transparent after a while, but the fade won't be very smooth. Some parts of the image might be denser and others completly wiped out during the fade.

household bleach comes normaly in 2.6% concentration, maybe a thinner solution gives better control


cheers, Bernhard
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#11 Clive Tobin

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Posted 12 December 2006 - 11:12 PM

...household bleach comes normaly in 2.6% concentration, maybe a thinner solution gives better control
cheers, Bernhard

Yes, it has to be substantially diluted, I forget how much, it has been a while. Perhaps 10:1 or 100:1 ?
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#12 Richardson Leao

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Posted 18 December 2006 - 09:40 PM

Yes, it has to be substantially diluted, I forget how much, it has been a while. Perhaps 10:1 or 100:1 ?



You can also try to re-bleach (onto K dichromate) after the 2nd developer before the fixer. I did it by accident when developing ecn2 c41; it bleaches out and gives a very faint image, but for BW it gives a 'white' black. In fact, what you'll be doing is getting the unexposed blacks white (as it did to the exposed blacks of the 1st developing). Also, it takes about 10 min to do so, so you could do the fade by gradually decreasing the speed of a rewind tank (remember that you have to turn it about 0.1 rpm to get 10' of exposition on the film surface, alternatively, you can just dip in a solution and gradually pul the film. If you do a stop bath after the 2nd dev, you can even do it in light until you get your desired results.
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#13 M Joel W

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Posted 24 December 2006 - 12:27 PM

My project was due the next day, and I don't have access to the photo lab so I just tried regular bleach.

I actually wanted a weird effect to cue flashbacks, so I drew flame shapes with a grease pencil and put bleach over it. It removed everything that wasn't penciled in so I had these cool flickery fade ins (from white) that looked surprisingly great.

The process sure smelled terrible and left me with a headache, but it was worth it. Thanks for all the advice. I would have loved to try more complicated effects, but my limited schedule got the better of me.
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Rig Wheels Passport

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