Eastman Color Negative

Eastman Color Negative (ECN) is a photographic processing system created by Kodak in the 1950s for the development of monopack color negative motion picture film stock.

The original process, known as ECN-1, was used from the 1950s to the mid-1970s, and involved development at approximately 25°C for around 7–9 minutes. Later research enabled faster development and environmentally friendlier film and process (and thus quicker photo lab turnaround time).

This process allowed a higher development temperature of 41.1°C for around three minutes. This new environmentally friendly development process is known as ECN-2. It is the standard development process for all modern motion picture color negative developing, including Fujifilm and other non-Kodak film manufacturers. All film stocks are specifically created for a particular development process, thus ECN-1 film could not be put into an ECN-2 development bath since the designs are incompatible.

The ECN-2 process has normally been reserved for high volume labs involving hundreds or thousands of feet of film in a linear processor. With companies like QWD that have made this available in a kit form for home use, this process now can be done on a small scale.