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B & W Bleach Bypass

Published : 25th May 2004


I can imagine (somewhat) the effects of doing bleach bypass on Black & White negative, but are there any examples out there. Or has anyone on the list done this?

Roderick Stevens
Az. D.P.
www.restevens.com
12On / 12Off



Isn't bleaching the process of removing the silver-thingies, leaving only the color-whatever material?

In black and white, if you remove the silver-x grains, there is nothing left...or do you mean, bypassing the bleach on a color print from a B&W negative?

Milivoj Ivkovic



>In black and white, if you remove the silver-x grains, there is nothing left.

Yeah, I thought about right after I sent the post. I'm sure you're right.

It's early

Roderick Stevens
Az. D.P.



>I can imagine (somewhat) the effects of doing bleach bypass on Black > & White negative, but are there any examples out there. Or has anyone >on the list done this?

The normal bleach step is in color processing only, to convert developed silver back into silver halide so it can be removed in the fixer and wash steps, leaving only color dye. Bypassing it leaves the silver in the image.

If you ran a B&W negative through a bleach step, there would be no image left, so all B&W processing "skips" the bleach step in a sense - there is no bleach step!

The most common method of increasing the contrast of B&W motion picture stock is extended development.

David Mullen ASC
Cinematographer / L.A.



Roderick,

I cant understand the fascination of screwing around with film stocks - especially black and white. As you can imagine I have shot a few miles of Kodak, Dupont and Agfa. The infinite possibilities possible with filters and exposure alone should interest even the hippest amongst us. That’s just on negative stock not even knowing the print stocks. I know I sound like the old foggy I am but I see a tendency of impatience with some who figure that if you fuck around enough with what’s given…that some magical thing will emerge which will make them different and thereby noticed.

I know about it because I've been there.

Vilmos started flashing color and I was on the phone with him and the lab on the percentage of flash. Years before I put mercury in an unexposed can of nitrate B and A to bring the speed up to 100 ASA. I see other people are respond to you. I probably should have read them first before I got on the soap box.

Take it easy but take it.

Haskell Wexler



Reversal stocks, yellow filtration, and underexposure/over developing all are ways of increasing B&W contrast...but...How about using polycontrast filters when printing?

I remember from my still B&W days using these filters with certain photo papers yielding much contrast control. They ranged form 1 to 4 in 1/2 grades 4 being the highest. I also remember using a dicro head when printing B&W negs with 40M and 40Y and 0C dialled in to give me a polycontast filter equivalent of 3.5.

I guess the only question here is can you used this type of filtration with B&W print or intermediate stocks or is this type of contrast filtration just "still" photo paper and chemistry process?

Richard W. Gretzinger
Director of Photography
www.richgretz.com



Richard W. Gretzinger writes :

>I guess the only question here is can you used this type of filtration with >B&W print or intermediate stocks or is this type of contrast filtration just > "still" photo paper and chemistry process?

"Polycontrast" filtering only works with "Polycontrast" papers, which BTW, do not have the contrast range of numbered printing papers.

Brian Heller
IA 600 DP



Richard W. Gretzinger writes :

>I remember from my still B&W days using these filters with certain photo >papers yielding much contrast control.

Polycontrast paper has a special emulsion that responds with varying contrast to varying colors of light. I don't think any B&W motion-picture print stocks were ever produced with such emulsions, but it's an intriguing idea.

However, varying print densities (contrasts) can already be produced by combinations of exposure and development time/temperature. And, of course, varying overall print contrast (by whatever means) won't, say, darken just your skies the way a red filter will when exposing the original negative.

Dan Drasin
Producer/DP
Marin County, CA



If the person asking about bleach bypass was in fact trying to get high contrast black & white, one possibility which hasn't been mentioned yet is shooting on sound negative. Not easy, but definitely very high contrast.

I believe Carlo Varini shot "Le dernier combat" this way, though I'm not absolutely sure.

Milvoj Ivkovic



I have recently been shooting 7263 and processing in reversal chemistry. You lose some sensitivity and some contrast compared with developing as pos, but it prints at a nice high gamma. Start around f/4 in bright sunlight as a baseline.

If you want more contrast, Sound Recording II film will give you higher contrast as reversal, and the EXR Sound Recording film will give even higher contrast. And you can process all of these in pos chemistry for still higher contrast.

Scott



Milivoj Ivkovic wrote:

> I heard (last year) that they don't anymore!

They still do if their website is to be believed :

http://www.ilford.com/html/us_english/bw.html

Tom Townend,
Cinematographer/London.



>If the person asking about bleach bypass was in fact trying to get high >contrast black & white, one possibility which hasn't been mentioned yet >is shooting on sound negative.

I'm not sure if this also has been suggested, but the commentary track on Confessions of a Dangerous Mind mentions the use of both color and B&W infrared film for some high contrast scenes in the very beginning of the movie.

Matt Davey
NYC - Digital Film Recordist



Matt Davey said :

>I'm not sure if this also has been suggested, but the commentary track >on Confessions of a Dangerous Mind mentions the use of both color >and B&W infrared film for some high contrast scenes in the very >beginning of the movie.

The flashbacks to Chuck's childhood were B&W Infrared and the interviews with Dick Clark, Jean-Jean, etc. etc. were all shot with Infrared Color.

I've been doing a lot of tinkering with those. Very interesting stuff. I experimented with the B&W in motion pictures stock and learned the hard way that the movement pitch needs to be finessed perfectly to accommodate the perforations. I ended up with an entire role of jittery exposures.

I've only shot the Color in slide film. I'd love the opportunity to shoot it in motion picture stock but it's INSANELY expensive at nearly $700 for a 400' roll.

Roderick Stevens
Az. D.P.


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