VNF-1 film through E-6 - sensitometric effect ?

[John Salim]

Hi All,
I get the occasional request to process old Ektachromes ( VNF-1 ) which I've always declined.
I know results can be poor, but does anyone know if processing a 'minimal' amount of VNF-1 film through an E-6 line will have a sensitometric effect ?

Many thanks,
John S

 

[eatfrog]

As someone who was thinking of doing a test roll of vnf1 in my e6 this is something i would like to know too.. never occurred to me that it might mess up the chems.

 

[Photo Engineer]

The VNF film may not be hard enough to withstand the 100 F process temperature and the emulsion may start to come off the support. That would make a real mess.

PE

 

[John Salim]

Would that only be with some film types PE ?
I clip tested a foot of '7240' and that survived absolutely fine.
It just came out light blue and flat contrast with usable images...... and probably gradable to some extent in post.

John S

 

[koraks]

According to the vnf-1 technical document from Kodak that I found, processing temperatures up to 43C are given for push processing and regular temperatures are the same or similar to C41 or E6. This seems to imply that the emulsion should survive a regular E6 process.

 

[Photo Engineer]

The original process used a pre-hardener which is not used now. If you get some of that film it can go soft on you. It uses Benzyl Alcohol in the CD and thus you might see some severe crossover. It uses a Persulfate bleach and this lack in C41 and E6 may also cause other problems such as lack of dye formation.

I could go on, but IDK, if it satisfies you it has worked.

PE

 

[John Salim]

Thank you Ron, it's much appreciated.
Do you mean severe crossover with densitometric curves, and would you say a small percentage of film ( say up to 10% ) might be ok to run without affecting control ?

Thanks again,
John S

 

[Rudeofus]

The VNF-1 process spec is fully available here. No prehardener step is included, in fact the only reference to a hardener in the whole document concerns the final rinse. Secondly, the process spec also lists a ferricyanide bleach, which should be a lot more available than the bleach accelerator needed for the persulfate bleach.

The biggest concern should be the color developer. VNF-1 appears to require higher temperature for CD step, and the CD requires Benzyl Alcohol. The latter is needed to sort of dissolve color couplers and make them available to the dye forming process. It was contained and required in older color processes, but no longer in E-6. The lack of Benzyl Alcohol in E-6 CD will therefore inhibit dye formation in your VNF-1 material to some extent. Not sure whether you can work around this by running the film through E-6 CD twice.

If you can get that CD step working and do some tweaks to FD, you should at least get at least somewhat identifiable images.

 

[Photo Engineer]

The original VNF process used a prehardener like E4. Now it does not. The film changed to fit the process. But, the couplers did not change and still need a strong oxidant to fully form the dyes (Persulfate or Ferricyanide) and the weaker E6 bleach may not fully form the dyes. In addition, the lack of Benzyl Alcohol (BZA) may cause loss in Dmax, particularly the yellow.

As a result, your pictures may be very blue.

Lack of Formalin may lead to greenish highlights as the magenta dye may fade rapidly.

PE

 

[Rudeofus]

Lack of Formalin may lead to greenish highlights as the magenta dye may fade rapidly.

E6 process does include Formaldehyde, either in the prebleach (7 bath kits) or in the final rinse (3 bath kits). As I said, FD may need some adjustments in timing, and CD will be the real head scratcher.

 

[Photo Engineer]

You are correct Rudi. I was somehow thinking of another suggestion to process E6 or E4 films through C41.

My bad.

Anyhow, it is there just in case. An FYI if you will.

PE

 

[John Salim]

.... so to get to my original question, will it have a sensitometric effect if I only process small amounts of film ?

Many thanks all,
John S

 

[Photo Engineer]

Only if the emulsion washes off the coating! Even small amounts of emulsion (or rem-jet if any film has such a layer) will ruin subsequent film in the same process.

PE

 

[fdonadio]

For the adventurous beings that would like to mix the VNF-1 chemicals, as per the PDF link posted by @Rudeofus, Kodak Reversal Agent RA-1 is a compound called Tertiary Butylamine Borane (CAS #: 7337-45-3).

Mostly everything else can be found easily.

 

[Anon Ymous]

I'd rather not mess with T butylamine borane and use an alternative fogging method. Exposure to light will probably work just as well.

 

[RalphLambrecht]

Hi All,
I get the occasional request to process old Ektachromes ( VNF-1 ) which I've always declined.
I know results can be poor, but does anyone know if processing a 'minimal' amount of VNF-1 film through an E-6 line will have a sensitometric effect ?

Many thanks,
John S

I never heard or read about such effect. what is it?

 

[fdonadio]

I'd rather not mess with T butylamine borane and use an alternative fogging method. Exposure to light will probably work just as well.

Nah, but then you don’t get the fun part!

 

[John Salim]

I never heard or read about such effect. what is it?

It's the photographic changes made to density, contrast and colour curves.
With proper process management ( 'process control' ) chemistry, replenishment etc.. with E-6 films, there shouldn't be much change running a decent E-6 line.
Putting 'alien process' film through it might change some of these parameters.

John S

 

[Photo Engineer]

If you do not process too much "alien" film there should be no problem.

PE

 

[Rudeofus]

A pro lab near me processes all regular film first, and at the end processes film for adventurous folks who do bad things to their material (intentionally). That way everybody shooting regular E-6 gets decent results, and the adventurous folks can experiment at will without messing up the chemistry for other people.

PS: Stannous Chloride is the currently recommended fogging agent for reversal materials. Not sure whether it works as part of CD, but it should and can be tested easily with a small test clip. Light exposure is, of course, the most environmentally friendly alternative.

 

[Photo Engineer]

Stannous Chloride can die unexpectedly and no longer function. It is always wise to test it beforehand.

PE