ENR process

rajvimal · October 3, 2010

hello sir.,

i want some details about ENR process.. im a film processing student. we have finished our diploma short film. in the subject is horror with romantic. my question is, i have normal exposed negative, its how to get a good result in ENR process. please help me how to print this negative and how to process the printing positive.... i want more information about ENR process.

David Mullen ASC · October 3, 2010

hello sir.,

i want some details about ENR process.. im a film processing student. we have finished our diploma short film. in the subject is horror with romantic. my question is, i have normal exposed negative, its how to get a good result in ENR process. please help me how to print this negative and how to process the printing positive.... i want more information about ENR process.

ENR is a print-only process offered by Technicolor Labs (fits into the ECP2 print processing line, not the ECN2 negative processing line). It leaves black silver in the print normally removed during processing, but is more controllable in strength than the all-or-nothing approach from using a straight skip-bleach technique. So ENR also involves skipping the bleach step at one point but then running the print through b&w chemistry to permanently develop in some silver, the rest being removed by the normal processing later in the line. Dominick Case could answer this more clearly than I can.

The general principle is that during normal processing, silver is developed alongside color dye clouds, then in the bleach step, the silver is converted to silver halide (resembling the unexposed silver halide in the print) so that it all can be removed during the fixing and washing steps, so skipping the bleach step leaves black silver in the print. But the effect on contrast is very strong, hence the partial skip-bleach effects of the ENR process.

Dominic Case · October 4, 2010

Dominick Chase could answer this more clearly than I can.

Hey David - I know it's been a while, but my name's still Dominic Case - what's with the new spelling? Or have you got someone else in mind? :)

Anyway, back to the topic . . .

The general principle is that during normal processing, silver is developed alongside color dye clouds, then in the bleach step, the silver is converted to silver halide (resembling the unexposed silver halide in the print) so that it all can be removed during the fixing and washing steps, so skipping the bleach step leaves black silver in the print. But the effect on contrast is very strong, hence the partial skip-bleach effects of the ENR process.

Exactly so for the skip bleach process. ENR has a similar end-result: retained silver image - but gets there a slightly different way: it's actually similar to the redevelopment process to add silver to optical soundtracks up until a few years ago when they all swapped to cyan tracks.

Here's the process: in the colour developer, exposed areas are developed to silver, and this process also produces colour dyes as David explains. Then, after a stop bath, undeveloped silver halide is removed (from unexposed areas)by the first fixer, leaving a silver plus dye image. The bleach bath then converts the exposed silver image back to silver halide. After a short rinse, the film passes into a black and white developer, which develops the silver halide back once again to a silver image. Since the amount of silver developed is dependent on time & temperature, it can be quite finely controlled. Finally the film is fixed, removing any silver halide left over from incomplete second development - and washed and dried.

The amount of silver present in the final image can be measured with an infra-red densitometer, which ignores the colour dye density. More silver results in a contrastier image, with deep colours being desaturated, but shadows made a darker and richer black.

David Mullen ASC · October 4, 2010

Sorry about the misspelling of your last name, I fixed it... hey, I'm tired, I've been working straight for the past three months! Don't know why I typed in "Chase" instead of "Case".