What is Bleach Bypass?

The traditional film process of bleach bypass leaves a black and white image superimposed over a color image. The technique has been around for a long time and is continually in vogue. It’s been used in iconic films through the decades, including Seven, Evita, Fight Club, Man on Fire, Million Dollar Baby, Minority Report, 1984, Saving Private Ryan and City of Lost Children. There are also lots more examples that imitate the effect in a Digital Intermediate color grade.

Each film lab had its own process to control the look. Some examples are:

ACE: Adjustable Contrast Enhancement (Deluxe)
CCE: Color Contrast Enhancement (Deluxe)
ENR: Ernesto Novelli Rimo silver retention process (Technicolor)
OZ: Olson/ Zacharia silver retention process (Technicolor)
NEC: Noir en couleur (LTC)
SB: Skip-Bleach (Fotokem)
SST: Standard Silver Tint (CFI)
EST: Enhanced Silver Tint (CFI)

How is it done in a traditional film lab?

Color film stocks begin as layers of black and white color separations made up of light sensitive silver halides. The silver halide layers are replaced with color dyes in processing. Reducing or skipping the bleach bath during color film processing leaves some or all the silver image and couples less of the color dye. The retained silver increases the contrast and grain, while the reduced dye leaves the image less saturated. Sometimes there is also a slight alteration of color balance, usually towards cyan. Maroons and blues tend to go black.

To alter the bleach bath, labs have to stop normal processing to reconfigure the machines, and less silver is recovered. Consequently, it is more expensive to do and there is usually an extra charge.

Each lab has its own recipe for the technique. Some can only do a complete bleach bypass; others can offer 50% reduction by skipping the bleach accelerator. Technicolor Rome is credited with introducing the concept and offered its own ENR process, which added a separate black and white development. This is more controlled, but not reversible.

Bleach reduction can be applied during any color processing including original camera negative (OCN), intermediate positive (IP), intermediate negative or release print. Skip bleach on negatives result in thin, blown out highlights, whereas skip bleach prints have deeper, heavier shadows and even less saturation than the OCN version. The results are always hard to predict, and so it is more common to apply the process to intermediates or prints. However, skip bleach on a large number of release prints adds even more cost and so there is the risk of distant or provincial markets making conventional prints and altering the intended look considerably.

The extra density created by the silver image can add as much as 1-2 stops of exposure and so it is usual to underexpose and use flat lighting to produce good results. Another way to control the contrast is to flash the film before processing. Many cinematographers also suggest using diffusion filters or nets to compensate for the harshness. Push developing strengthens color saturation, but also increases the density. In theory, a skip-bleach film can be re-processed to restore it to normality. However, if any of these compensations have been made, normal development is likely to create a thin grainy negative. Also, remember that bleach bypass film is less stable in long-term storage.

What are some modern variations on bleach bypass?

The double inter-positive is a less common process that involves making a color and a black and white inter-positive and then exposing the negative to both. This offers greater control but is time consuming. The results are low saturation, but not as much contrast or richness in the blacks as full skip bleach.

Precision and flexibility were the main reasons for replicating this effect in post-production instead of using the chemical process. Today, most content is captured with digital cameras, so naturally software versions of the process are needed. Since the film process was unpredictable, the trick to Digital Intermediate solutions is to create a relationship between saturation and luminance so that changes to one affect the other.

Once the basic look is created, a colorist can refine the look with additional layers. Popular finishing touches are glowing highlights, and solid black layers. Both of these are easily achieved with luminance mattes.

Restoring parts of the image to a normal look can produce striking results that would be impossible to match in the film laboratory. The normal region could be the inside of a soft vignette, but a more interesting approach is achieved with a matte. For example a blue sky or a warm skin tone could be retained while all other parts of the image have the high contrast, low saturation of a bleach reduction effect.

How would you use bleach bypass?

It is important to use any of these techniques with care. Bleach Bypass is a photographic cliché, often used as a copycat look. However, like all other common photographic styles, it has its own symbolism and cultural meanings. Like black and white, it is an abstraction of reality. The reduced color makes the images colder and less personal, especially when skin tones are involved.

Feature films have further defined the look by associating it with war and documentary genres, so it is well suited to subjects that wish to portray a cold, calculated reality. The abstraction can also emphasize shape and form to create beautiful, timeless compositions. These qualities are also true of monochrome images, but the infusion of natural color adds a hint of warmth lacking in those techniques.

Bleach reduction relates to monochrome just as watercolor relates to charcoal. The colorist can reduce the coldness by using warmer tints, or restoring warm colors, such as skin tones. The heavy contrast – that infers oppression and darkness – can also be countered by lightening mid tones and blowing out highlights. There are many variations that use the look intelligently, so that it adds meaning to the images. If the metaphors of style conflict with the message of the content, then the illusion is lost.

Watch a video tutorial of bleach bypass techniques in DaVinci Resolve here.

That’s it – everything you need to know about bleach bypass and its variations. There are plenty of plug-ins that create the look too, but doing it yourself is so much more fun.

List of some films which used bleach bypass type processing:

1984 used bleach-bypass Kays Lab
Alien: Resurrection used about a 50 percent level of ACE
American Gangster used the OZ process
Amistad used ENR
Bird used ENR
Bulworth used ENR
City of Lost Children used NEC
Delicatessen used bleach-bypass
Dick Tracy used ENR
Desordre used bleach bypass
Evita used a VariCon and diffusion filters combined with a 30% ENR printing
Fallen used ENR
Fight Club used a silver retention process
Game used ENR
Kansas City used EST
Ladyhawke used ENR
Last Emperor used ENR
Little Buddha used ENR
Lost Souls used bleach-bypass
Man on Fire used a silver retention process
Michael Collins used ENR
Million Dollar Baby used ENR
Minority Report used a SB process to the negative
Monsieur Hire used bleach bypass
Munich used ENR
Payback used the CCE printing process,
Reds used ENR
Ronin used pull-processing of the neg combined with CCE printing
Rookie used ENR
Saving Private used ENR on the prints
Seven used Deluxe's CCE printing
Terminator Salvation used the OZ process
Tucker used ENR
War of the Worlds used ENR
X-Files used ACE

This is an update to my earlier article that described bleach bypass in a DaVinci hardware color corrector, Adobe Photoshop and Digital Vision Film Master software color system. Read the original text here.

Watch a video tutorial of bleach bypass techniques in DaVinci Resolve here.

Thanks to:

https://forum.fanres.com/thread-1252.html

https://theasc.com/magazine/nov98/soupdujour/pg3.htm

For more articles check out my archive and sign up to my newsletter.

For more inspiration take one of my courses.

more ideas to explore...