Removal of Anti-halation backing on C-41 color film (35mm)

[Aidan G]

Hi im wondering if its possible to remove the Anti-halation backing on C-41 film before shooting. I have seen some videos on how to remove it from Kodak cine film. There process that used baking soda but I understand that movie film has a special layer that can be removed. I was wondering if I could use this process for still film.

 

[MattKing]

For C-41 film, I don't believe that it (the anti-halation) is coated on the back. I believe it forms part of the emulsion.
The remjet used for cine film is on the back, and it is there for other purposes besides anti-halation that relate to how fast cine film moves through cameras.

 

[Donald Qualls]

I think the videos you've seen are for removing the remjet coating on cine films like Visions3. Cinestill's bread and butter is their process for removing that coating without damaging the film or exposing it to light, allowing them to then load it into cassettes or roll it on 120 spools for still camera use.

I think it's pretty unlikely you or I will manage that, but the good news is, there's no need for it with C-41 films (which are made for still cameras, not cine); they don't have remjet. The only still film I'm aware of that had remjet was Kodachrome, and it's been out of production for so long that the last lab that could give it the original process closed its line more than a decade ago.

For other film, antihalation is divided into two broad categories: dyes, either in a subcoat between the emulsion proper and the film base or on the "base": side of the film, colored base, or a colloidal silver layer (again, usually in a sub coating, and mainly seen as the yellow filter layer in color films, or as antihalation in in B&W cine films intended for reversal processing). Except for a colored base (like the gray base in Tri-X), antihalation is generally intended to be removed by the specified process for a particular film, so becomes significant to us only if we cross-process the film in a way that doesn't do that -- like shooting Foma R100 for negatives or processing most C-41 films in B&W chemistry.

For C-41 film processed in C-41 chemistry, the bleach and fix steps remove the filter layer along with the developed silver and undeveloped halide. You don't have to do anything beyond follow the steps in the C-41 kit, or pay a competent lab to process your film.

 

[Aidan G]

Would it be possible to remove any layers out of the film ( UV, Anti- halation, Colors ect.) Because i'm experimenting with some cheap film to see if I can get a unique look to it without changing the development process. I know you said that CineStill has a process that prevents them from damaging the film when they manipulate it. Say it's possible you could remove a layer of film using some sort of substance. Couldn't you just unload the film from the canister and put it into a paterson tank? Then after you have mixed the "substance" and taken off the "certain layer" of the film you would hang it up to dry in a pitch black room. After its dried could you then spool it back up without damaging it?

 

[MattKing]

Most of the components of the film emulsion are intermixed - not really layers.
If there are any layers, they are underneath the light sensitive parts, and you can't get at them without removing (and destroying) those light sensitive parts.

 

[Aidan G]

Would I be able to manipulate the look of the film without changing the development chemistry or changing camera settings. What I mean is by default the film would give that "certain" look without changing anything out of the ordinary.

 

[MattKing]

Would I be able to manipulate the look of the film without changing the development chemistry or changing camera settings. What I mean is by default the film would give that "certain" look without changing anything out of the ordinary.

You could damage it with extreme heat, physical manipulation (scratching or abrading) or X-ray exposure.
You could also double expose it.

 

[cmacd123]

most C-41 film has a silver layer under the colour layers, which will be removed by the bleach step. I would have no idea if their is a way to bleach that layer without making a mess of the other 3 or 4 layers of colour recording material.

I also wonder why? their is a risk of Multi coloured fringing around every bright object if there is not an Anti-halo layer.

 

[YoIaMoNwater]

Would I be able to manipulate the look of the film without changing the development chemistry or changing camera settings. What I mean is by default the film would give that "certain" look without changing anything out of the ordinary.

What do you mean by that "certain" look? Do you mean when there's halos around light sources like how Cinestill800 looks? If that's the effect you're trying to get then Film Washi F is the only one that I know that doesn't empty your bank. Although it's a BW film, it's cheaper af than Cinestill.

 

[mshchem]

Why????

 

[koraks]

You could redscale expose it. Load film reversed (with the backside facing the front) and overexpose by 2-4 stops. You'll get reds, oranges and yellows shifting to greenish in bright highlights. Process normally.

Why????

Good question.

 

[AgX]

I also wonder why? There is a risk of Multi coloured fringing around every bright object if there is not an Anti-halo layer.

Gaining those halo artefacts are seemingly just the intention of the OP.

 

[Aidan G]

Why????

I was wondering if it was possible to remove the anti-halation layer in still 35mm film. I have been experimenting with some cheap experimental film to see if I can give a unique look to it.

 

[Aidan G]

What do you mean by that "certain" look? Do you mean when there's halos around light sources like how Cinestill800 looks? If that's the effect you're trying to get then Film Washi F is the only one that I know that doesn't empty your bank. Although it's a BW film, it's cheaper af than Cinestill.

Yeah overall I was seeing if I could get some sort of unique look to some film i'm experimenting with.

 

[mshchem]

I was wondering if it was possible to remove the anti-halation layer in still 35mm film. I have been experimenting with some cheap experimental film to see if I can give a unique look to it.

Look up some really old Kodak formula books. You will find formulas of all kinds for dyes for lantern slides and movie films. You can tone black and white film, you need silver to tone. Black and white reversal films offer more control than fiddling with color film.
If you want to wash the dye off tabular grain color films, I'm not really sure what this dye does, it's definitely not remjet. Remjet is used on motion picture negative film for a couple reasons (that this amateur knows of) cine film is on a Estar polyester base that is stronger, it is more subject to light piping, which is "halation" also, cinema film cameras churn through miles of film, some of the internal parts are smooth as silk chrome plated steel, the remjet dampens any tiny reflections. If you want to eliminate the dye, get a big bucket of warm water, maybe 2 or 3 buckets, pull the film out of the cassette, leave it attached to the spool, and the spool in the cassette. Dunk the film and swish it around for a couple minutes, then go to the next bucket, repeat. Hang the film to dry, don't let water get into the cassette. When it's dry wind it back into the cassette. Maybe add some random artistic scratches. I have no idea how, if any effect it would have.
If you have ever dealt with remjet you would know it it's a mess.

 

[cmacd123]

Remjet is used on motion picture negative film for a couple reasons (that this amateur knows of) cine film is on a Estar polyester base that is stronger, it is more subject to light piping, which is "halation" also, cinema film cameras churn through miles of film, some of the internal parts are smooth as silk chrome plated steel, the remjet dampens any tiny reflections. .

with a few exceptions - like IMAX and high speed cameras, Normal Movie Negative is on an acetate base.

REMJET is great for anthallation, it is also Conductive so helps keep down static. (one Lightning bolt defect would ruin an entire shot) and also provides a bit of lubrication. (the film goes through the Camera at 90 feet a minute)

the Print film - used in Projection used to also have REMJET and is on Polyester base, but the current 2383/3383 has a permanent antisatic coating on the back - Light piping is not an issue as it is only used in the dark.

the anti halo on Still film is between the base and the emuslion, and is cleared by the same "Bleach" that turns developed silver back into a halide so it can be removed by the fixer. Still colour is almost universally on a acetate base.

 

[AgX]

If you want to wash the dye off tabular grain color films, I'm not really sure what this dye does, it's definitely not remjet.
Remjet is used on motion picture negative film for a couple reasons (that this amateur knows of) cine film is on a Estar polyester base that is stronger, it is more subject to light piping, which is "halation" also, cinema film cameras churn through miles of film, some of the internal parts are smooth as silk chrome plated steel, the remjet dampens any tiny reflections.

The dyes serve + several tasks, as spectral sensitizing , filtering and adding neutral density.
Polyester film does not add more halation than acetate film base.
There are cine camera films without rem-jet, as all b&W films and all Super-8 films.

 

[mshchem]

with a few exceptions - like IMAX and high speed cameras, Normal Movie Negative is on an acetate base.

REMJET is great for anthallation, it is also Conductive so helps keep down static. (one Lightning bolt defect would ruin an entire shot) and also provides a bit of lubrication. (the film goes through the Camera at 90 feet a minute)

the Print film - used in Projection used to also have REMJET and is on Polyester base, but the current 2383/3383 has a permanent antisatic coating on the back - Light piping is not an issue as it is only used in the dark.

the anti halo on Still film is between the base and the emuslion, and is cleared by the same "Bleach" that turns developed silver back into a halide so it can be removed by the fixer. Still colour is almost universally on a acetate base.

Kodak Vision films, even the negative film is n polyester

 

[AgX]

Only in the Special Order versions.