How can I remove anti-halation layer from C41 film

Bohngy · Jul 20, 2009

Hi all,

I'm home developing 5x4 sheet film in some home made tubes. My problem is that the film 'sticks' to the inside of the tube and the chemistry often doesn't completely remove the anti-halation layer from the back of the sheet.

This isn't a problem with black and white, as the anti-halation layer is water soluble and I could 'wash' it off after fixing.

As the C41 film doesn't seem to have a water soluble AH layer, can I put the film, after Blix, back into the developer to remove the AH layer, then a brief blix (1minute maybe) before the normal 5-7min rinse?

Sorry if this is a silly question, but I'm rather new to this 'homebrew" C41 stuff.

Thanks in advance

Ed Sukach · Jul 20, 2009

I'm watching this thread... I did not think that C41 HAD an "anti-halation" layer.
The respooled motion picture stock from Seattle Film DID, much to the horror of a few one-hour machine operators (one roll would gum up the whole works) but that was NOT "C41".
I've developed a few (actually sgnificantly more than a "few") rolls of 35mm and 120, and haven't had to "remove an anti-halation layer" yet.

Bohngy · Jul 20, 2009

Ed Sukach said:
I'm watching this thread... I did not think that C41 HAD an "anti-halation" layer.

Hmmm... that's got me thinking. I thought all films had an anti halation layer. Either way I'm getting streaks that look to be originating on the back, i.e. non emulsion, side of the film. I assumed it was an AH layer because I've seen the same problem when developing 5x4 B&W sheet film...

can anyone shed a little light on this (no pun intended)?

Anon Ymous · Jul 20, 2009

Ed Sukach said:
I'm watching this thread... I did not think that C41 HAD an "anti-halation" layer.
The respooled motion picture stock from Seattle Film DID, much to the horror of a few one-hour machine operators (one roll would gum up the whole works) but that was NOT "C41".
I've developed a few (actually sgnificantly more than a "few") rolls of 35mm and 120, and haven't had to "remove an anti-halation layer" yet.

All films have AH layer. C41, E6 etc are no exceptions. The other MP films you mention have remjet coating. It might function as an AH layer, but it's not just for that.

Ian Grant · Jul 20, 2009

C41 & E6 films are best processed in a way that allows flow of chemistry to front & back, Jobo make 5x4 reels and HP & Yankee tanks are also suitable.

Ian

rternbach · Jul 20, 2009

I am a newbie so my answer is in the form of a question: Can you pre-rinse the film in distilled HOH for a minute before processing and will this wash off the halation layer and prevent the film from sticking to the tubes?

Best,

Rudy

Ian Grant · Jul 20, 2009

Unfortunately few films allow that usually just Adox/EFKE B&W films.

Ian

Ed Sukach · Jul 20, 2009

Anon Ymous said:
All films have AH layer. C41, E6 etc are no exceptions. The other MP films you mention have remjet coating. It might function as an AH layer, but it's not just for that.

There might be a film construction where there is some sort of "provision" for controlling "halation" - but I don't know about a specific "layer" dedicated to that purpose, except fpr the "rem-jet" on motion picture stock.
Be that as it may, NONE of the Black and White, C41, E6, IR ... or anything else I have processed has required "anti-halation layer removal". As far as I know, there is no specific "step" or "chenical solution" specifically dedicated for that puropse, and I for one have never noticed a need for that, either.
But ... I certainly am NOTHING like an "expert" here - possibly PE (who, in my book, has passed that requirement long ago) can offer resolution here.

nickrapak · Jul 20, 2009

I believe that the anti-halation layer in still films (except Kodachrome) is developer-soluble, that is the developer chemically changes the opaque part of the AH layer, rendering it transparent. The only film currently available without an AH layer is (IIRC) Efke IR820 Aura.

Anon Ymous · Jul 20, 2009

Ed Sukach said:
There might be a film construction where there is some sort of "provision" for controlling "halation" - but I don't know about a specific "layer" dedicated to that purpose, except fpr the "rem-jet" on motion picture stock.
Be that as it may, NONE of the Black and White, C41, E6, IR ... or anything else I have processed has required "anti-halation layer removal". As far as I know, there is no specific "step" or "chenical solution" specifically dedicated for that puropse, and I for one have never noticed a need for that, either.
But ... I certainly am NOTHING like an "expert" here - possibly PE (who, in my book, has passed that requirement long ago) can offer resolution here.

I'm not an expert either, but AFAIK, C41 films have the AH layer between the film base and the red sensitive (final) layer. It becomes transparent IIRC with development. If anybody knows specifically, I'd like to know.

Photo Engineer · Jul 20, 2009

All Kodak films have an AH layer somewhere in the structure either below the emulsion layer or behind on the back. The motion picture films and Kodachrome use Rem-Jet as the AH layer and this must be removed in the process by a special method.

The other films allow for removal in the process so with C-41, try soaking the film in bleach for about 5' at room temp, then wash 5', soak in fix 5' and wash 5' and then soak in stabilizer. This should remove the "stain" as the AH layer in some color films is gray silver which must be bleached out. If this does not work, repeat with longer times.

PE

Bohngy · Jul 20, 2009

Thanks nickrapak, I'll give it a go with the dev, stop and wash process I was talking about.
Ed - I'm not trying to invent an extra AH removal step, my developing technique, using tubes and not tray/tanks, is not removing all of the AH layer.... or the layer I BELIEVE to be the AH layer!

either way, there's still something that's streaking across the film...

Bohngy · Jul 20, 2009

Thanks for your expert input PE, could I just do 5 mins in Blix at RT?
thanks

Photo Engineer · Jul 20, 2009

Well, the RA Blix is about 50% or more weaker than the C41 bleach/fix so I would use 10 - 15 minutes and then a 10 minute wash and then stabilzer.

PE

Bohngy · Jul 20, 2009

Many thanks for all your replies, especially Photo Engineer. I chose to soak each neg in developer 2 mins, Blix at room temp (5 min) then washed and stabilised... and I think the 'marks' have now disappeared, so I guess it was an anti-halation layer.

One interesting observation is that I also have 2 cross processed sheets of Kodak EPP, one of the two exhibits the same 'streaks' - using the same technique as above, the streaks haven't disappeared!

B&W seems easier at the mo!

3 Olives · Jul 20, 2009

Anon Ymous said:
All films have AH layer. C41, E6 etc are no exceptions. The other MP films you mention have remjet coating. It might function as an AH layer, but it's not just for that.

Efke IR820 Aura B&W Infrared does not have AH backing. No, I'm not smart - just happened to have found it out trying to find a film similar to HIE.

3 Olives · Jul 20, 2009

3 Olives said:
Efke IR820 Aura B&W Infrared does not have AH backing. No, I'm not smart - just happened to have found it out trying to find a film similar to HIE.

I see where nickrapak pointed this out in an earlier post - proof that I wasn't lying when I said I'm not smart.

Sirius Glass · Jul 20, 2009

3 Olives said:
I see where nickrapak pointed this out in an earlier post - proof that I wasn't lying when I said I'm not smart.

I don't know. In a gin martini you would be just about right!

Steve

OldBikerPete · Jul 21, 2009

When I pre-soak my Kodak Portra 160VC in distilled water for 5 min in the rotating Jobo tank at 100F before replacing the pre-soak with developer, the pre-soak comes out colored a deep red/brown. I've always assumed that that was the anti-halation layer dissolved.

Photo Engineer · Jul 21, 2009

The color coming out during the prewash is mainly due to acutance dyes and trimmer dyes. The latter adjust the speeds of the 3 layers or trim them, to assure an exact speed to the film and an exact speed relationship between layers. The acutance dyes enhance sharpness by reducing the effects of turbidity in the coating.

PE

archer · Jul 25, 2009

Dear Bohngy;
When processing film in smooth walled tubes I use fiberglass window screen between the film back and tube wall. Just cut some 4x5 pieces to fit and load the tube making certain that the screen is against the back of the film. The screen allows the chemicals to reach the entire film back and problem solved. Be sure to rinse and dry the screen before use.
Denise Libby

Anscojohn · Jul 25, 2009

Photo Engineer said:
The color coming out during the prewash is mainly due to acutance dyes and trimmer dyes. The latter adjust the speeds of the 3 layers or trim them, to assure an exact speed to the film and an exact speed relationship between layers. The acutance dyes enhance sharpness by reducing the effects of turbidity in the coating.
*******
P.E.,
Nothing in this discussion is related to anything I do in the darkroom and probably never will. I just want to chime in to say I sure am glad you stick to this user's group to provide answers like the above. Thanks.

Sirius Glass · Jul 25, 2009

Anscojohn said:
Photo Engineer said:

The color coming out during the prewash is mainly due to acutance dyes and trimmer dyes. The latter adjust the speeds of the 3 layers or trim them, to assure an exact speed to the film and an exact speed relationship between layers. The acutance dyes enhance sharpness by reducing the effects of turbidity in the coating.
*******

Click to expand...

P.E.,
Nothing in this discussion is related to anything I do in the darkroom and probably never will. I just want to chime in to say I sure am glad you stick to this user's group to provide answers like the above. Thanks.

ditto

Steve

Photo Engineer · Jul 25, 2009

Thanks guys. I appreciate it and am glad to help.

PE

How can I remove anti-halation layer from C41 film

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