How Motion Picture Film Is Duplicated and Distributed

Having developed the enormous negatives out of my Mamiya RZ67, I couldn’t help but wonder what would happen if I photographed them on another colour-negative film. Would the image become a positive?

As I proceeded with this explorative exercise, my research led me to learn about an essential component in the motion picture finishing process that I had inadvertently approximated: interpositive film.

Interpositive film was vital in cinema production before digital editing workflows became the norm. Back then, getting movie reels finished and delivered to the theatres involved many steps.

Modern movies* that are shot on film go through the digital intermediate workflow, which makes production much cheaper while suffering less quality loss from analogue distortions. And so is the case with still photography, where most of our images are scanned, colour-corrected using software, and distributed on websites/via e-mail/on social media.

In this article: How movies were edited and distributed in the pre-digital era. How movies (that are shot on film) are distributed in the digital era. Cristopher Nolan’s IMAX film duplication and distribution. Support this blog & get premium features with GOLD memberships!

✱ — Except for Cristopher Nolan’s movies. His features are still shot and distributed via purely analogue workflow parallel to the digital release.

In this article, I’ll contrast the traditional process of film finishing and duplication to modern workflows and review a few contemporary examples of movies that used either. I’ll also discuss how the interaction of digital processes and the analogue medium have given film (whether still or cinema) a new life in the modern world.

How movies were edited and distributed in the pre-digital era.

Before we could use computers to edit video footage, film had to go through multiple duplication steps. The cutting and stitching had to be done by hand or on a special machine that would aid the mechanical process. Each time it got duplicated, there would be some degradation in resolution and colour quality. But to make a good movie, it would have to happen a few times:

Having shot all the takes, the film camera reels would be developed as negatives and cut into a cohesive sequence called a work print. This was aided by transferring the film onto videotape and using the result to composite the images as positives, which then got “locked” and programmed into another machine that would automatically cut the camera negatives. Before the 1960s, this work was done by hand with some mechanical assistance.

The re-assembled camera film would then get duplicated via wet gate: a process of contact printing while submerged in liquid (which improves the transfer quality). This technology is obviously superior to my experimental half-frame capture of the medium format negative (above). But the idea is similar: capturing a film negative on a second film negative to create a positive image, called interpositive film.

Interpositive film is used for layering colour corrections, special effects, transitions, and dubbing. Once the first pass of the work on interpositive is done, a new transfer is made into an answer print (also a positive) — a rough assembled copy used for approval or planning further changes, which would then be reflected on consequent answer prints.

Once the final answer print is approved, interpositive film is transferred onto a new negative, called internegative. Internegative is then used to create numerous transfers onto release prints, which are the copies that movie theatres get.