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Processing a color negative film as a positive?


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Hi

Can a negative color film be processed using a E6 reversal process? If yes what kind of results could be expected?

The film is a color negative 16mm film. Eastman 7291 or 7297.

Just curious if anyone has experimented with this.

Thanks

Dennis

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No offense, intended Dennis, but you really need to hit the books and get out some photography/cinematography texts. They will answer all of your questions.

 

First off, quit using old film.

 

To answer your question though, ECN-2 processed in E-6 will have high contrast, still have the weird color base cast (though I want to say it will be reversed), and there will be a speed change.

 

You'll be hard-pressed to find an E-6 lab to do it for you.

 

I wouldn't recommend that a beginner do E-6 themselves. There are two time- and temperature-critical development steps.

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To answer your question though, ECN-2 processed in E-6 will have high contrast, still have the weird color base cast (though I want to say it will be reversed), and there will be a speed change.

 

Should that not be a really low contrast Karl? Generally you should get low contrast, the orange neg mask and lots of grain. Try and over-expose by a stop and push a stop. I tried it a while ago and it did not really look that great, all the highlights were seriously blown out. It looked bad so I did not go back and try it again.

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Thanks Guys

 

First off I wouldn't think of doing this kind of thing for an actual school project. Unless....... <_<

 

Second I don't actually have these films, just wondering out of curiousity.

 

Doesn't any one here have a experimental nature :lol: :lol:

 

Third I have done more than my fair share of E6 processing at home. I find it a very well

behaved process. The temperature deal is not a problem for me.

 

Seriously though I think E6 is a very nice process and wouldn't hesitate recommending it to anyone.

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No, I think it's going to be high-contrast, keeping in mind that the developer, not the film type, determines contrast. Maybe you are right though. I've never cross-processed anything. I processed color film once as B&W, long story.

 

 

Here is some recommended reading on the subject:

 

"Photographic Chemistry In Black-and-White and Color Photography" George T. Eaton Third Ed. 1980

 

"The Photographer's Handbook" John Hedgecoe Third Ed. 1992 p.155 is on cross-processing

 

&

 

"The Book of Special Effects Photography" Michael Langford, 1981. p. 100

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Third I have done more than my fair share of E6 processing at home. I find it a very well

behaved process. The temperature deal is not a problem for me.

 

Unless you can control the process to within +/- 1/4°F (0.13-8/9°C), you aren't going to get optimal results.

 

Rose-colored glasses?

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I don't think it's quite that critical Karl. I've processed e6 with +- a degree or so with very good results.

Have you actually processed film with e6?

With 20 or more rolls of 135 36 exposure I had absolutely no problems. I've even processed movie film with no problems except keeping dirt off and a few water spots.

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Hi

Can a negative color film be processed using a E6 reversal process?

Just curious if anyone has experimented with this.

I have not experimented, but remember that you will have to deal with the rem jet with any processing of Movie neg.

 

I would imagine the mask would still be there, which you could dial out when printing or scanning.

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Have you actually processed film with e6?

With 20 or more rolls of 135 36 exposure I had absolutely no problems. I've even processed movie film with no problems except keeping dirt off and a few water spots.

 

Yes.

 

Well, maybe you didn't have problems, but try matching a color that you photograph on those twenty different rolls so it is consistant throughout a movie.

 

This isn't still photography. If you want to talk photography, go to a still photography forum.

 

If you want good, consistant, professional, results that don't take hours and hours of nitpicking and manipulation to get to match cross-shot, you'll keep it to within a quarter degree Fahrenheit.

 

Are you a hobbyist daydreaming or do you actually want to make movies? Most of the stocks you've mentioned haven't been made since before I was born.

 

Not trying to be harsh or anything, but mental masterbation, like other types, should really be a one-person activity. . .

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  • 2 weeks later...
To answer your question though, ECN-2 processed in E-6 will have high contrast, still have the weird color base cast (though I want to say it will be reversed), and there will be a speed change.

 

Should that not be a really low contrast Karl? Generally you should get low contrast, the orange neg mask and lots of grain.

 

I've never done this (nor wanted to), but the answer to the contrast debate is that the ECN2 material would have a higher contrast than it would get in the normal ECN2 process, but it will be a positive (orange masked) image, and by comparison with the positive image you'd get with E6 reversal type films, it would be a lower contrast.

 

By the way, the orange colour of negative stock (however it is processed) is NOT the base, which is clear. It is the colour of unexposed/undeveloped dye couplers, and it's a technique of improving colour reproduction.

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Hmm Grant, looks like someone was right and someone was wrong! :P

 

Thanks for "backing me up" Dominic ;)

 

BTW, do you know if the orange mask, in fact, gets inverted so that it is blue? I want to say I remember seeing an offset reproduction of film processed this way (think it was a C-41/still variety of neg film though) and I seem to remember it being bluish-purplish in coloration.

 

That is interesting, too, that the inherent contrast of a film is partially a property of the film and partially of the developer; otherwise ECN-2 cross-processed would have the same very-high contrast as E-6 film in its native process.

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Hello all,

I've cross processed ecnII film in E6 chemistry a couple of times. Yes, the result is a lower than normal reversal contrast golden hued low colour saturation positive. You need to both UNDER RATE the film stock by about two stops AND PUSH PROCESS the film by about two stops. So if you are using 200t for instance, try exposing as 50 asa and pushing the processing 2 stops. Its not hard at all and I suggest you try it if you are set up to process e6 at home. Open the tank after the post-first developer wash and take the film out of the tank to remove the rem-jet backing on the film with a cloth. Then continue with the rest of the e6 process.

 

No, the orange bias of the coloured couplers isn't reversed - that orange colour is a colour added to the colour couplers of negative film and is only present when the couplers are in an un-activated state. Colour photographic images on film are made by attaching (?) colour couplers to the silver haylide emulsions. When the silver haylide is converted to metalic silver during development, the attached colour couplers are activated resulting in a dye image forming where the metalic silver formed. With colour reversal film, these colour couplers (I belive) have no inherent colour, whereas with colour negative film these colour couplers are themselves given a colour during manufacture. Hence the colour couplers of colour negative film are coloured colour couplers. A mouthfull. This added coulour isn't actually the orange you see. Rather, the colour couplers attached to both the red and the green silver haylide layers on the film are each given a different colour, the net effect of which is the orange colour.

 

However, since the reversal process involves converting ALL of the colour-coupled silver haylide emulsion on the film (first as a negative, then the positive half in the second developer), and since the colour couplers are ''activated' (right word there?) precisely by the process of the silver haylide being converted into metalic silver during development, it would seem that ALL of the coloured couplers would have been activated 100% by a reversal colour process. So if all the coloured colour couplers have been activated. Why does ecnII film cross processed in e6 still appear golden? Its because the colours added to the two coloured colour coupler layers in negative film (red and green) are added to compensate for the inherent colour bias that the respective colour dye images (the cyan and magenta) will have. So even though with this cross processing all of the coloured colour couplers have been activated and thus the colour given to them in manufacture is no longer present, it is nonetheless the case that the positive dye image produced still shows the dye bias of the cyan and magenta colour dyes.

 

cheers,

richard

Edited by Richard Tuohy
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However, since the reversal process involves converting ALL of the colour-coupled silver haylide emulsion on the film (first as a negative, then the positive half in the second developer), and since the colour couplers are ''activated' (right word there?) precisely by the process of the silver haylide being converted into metalic silver during development, it would seem that ALL of the coloured couplers would have been activated 100% by a reversal colour process.

 

Not quite, otherwise the normal slide film would come out black!

 

The colour copolers are not activated in the first (Black and white) developer, but are in the second (Colour ) developer. Thus the colour image is ONLY formed in the second developer.

 

The mask is formed only where the colour couplers are NOT used - so you would expect the orange to show in areas where you would otherwise have clear film.

 

The orange mask is a Photo Engineer party trick that hides (thus the term "mask") some limitations of the dyes.

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Not quite, otherwise the normal slide film would come out black!

 

It would indeed come out black if there was no bleach in the process.

 

The colour copolers are not activated in the first (Black and white) developer, but are in the second (Colour ) developer. Thus the colour image is ONLY formed in the second developer.

 

Of course. You are right there charles - only the second (colour) developer activates the colour couplers.

 

The mask is formed only where the colour couplers are NOT used - so you would expect the orange to show in areas where you would otherwise have clear film.

 

Yes, again that is right. Since not all the coloured colour couplers are activated in the reversal process (unlike I said in my original post) there are some coloured colour couplers remaining in the final reversal image.

 

The orange mask is a Photo Engineer party trick that hides (thus the term "mask") some limitations of the dyes.

 

That's right. The extent of the orange bias of the coloured colour couplers is the same as the extent of bias of the dyes used. Thus the two balance out to make for a uniform bias regardless of the amount of image formed. Of course, it would be possible to make colour neg film that didn't use coloured colour couplers, but rather the same couplers used in colour reversal film. The reason they don't is that the reversal dyes are not as accurate in colour reproduction. Since reversal is usually only a one step (not printing) system the error doesn't accumulate so it is less of an issue. But now that colour neg is increasingly being used for scanning only, it would probably be less of an issue ... except that the low gamma of colour neg probably puts more pressure on the colours ...

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The magenta coupler is coloured yellow to correct for unwanted yellow absorption of the magenta dye. The cyan coupler is coloured magenta to correct for the unwanted magenta absorption of the cyan dye. The yellow coupler is colourless because a magenta coloured coupler is not availbale for the yellow dye and also the yellow dye does not have unwanted absorptions as serious as the other two dyes.

 

I have some samples in my collection of single layer coatings of colour negative of each layer with and without the coloured couplers. These were made in the Kodak Research Laboratories when I worked there in the early 1960's.

 

Brian

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