Kodachrome: The Film that Changed the Way We See

By Abhay Sharma, Paul Sergeant Back to


Kodachrome was a beautiful film– bright vivid colors, low grain and images that jumped out of the screen and filled the projection room with the awe of mountain landscapes, close-up portraits and children playing on backyard swings. After a successful 74-year run, Eastman Kodak announced in June 2009 that it would soon discontinue sales of Kodachrome. It’s interesting to take a look at both the history and science of this remarkable product.

The Leopolds

Kodachrome was not the first color film (color photography had existed with techniques such as Autochrome and Dufaycolor), but Kodachrome was the first practical film for a mass audience. The inventors of Kodachrome, Leopold Mannes and Leopold Godowsky, met as teenagers. Both were fascinated by the popular Brownie camera, and both longed for a way to take color photographs themselves. The Leopolds were musicians by trade, but were invited to join Kodak in Rochester to realize their invention. They worked for Kodak for a number of years before both returned to their musical roots. Within the company this duo was known as “Man and God!” Mannes died in 1964, and Godowsky in 1983. After their deaths, both were inducted into the Inventor’s Hall of Fame.

Color Film 101

In the 1930’s Kodachrome was first sold as 16mm movie film, and within a few years as 35mm slide film. Most color film in the world is based on the 3-layer principle, where each layer of the emulsion is sensitive to red, green or blue light.

In general, most color film is actually individual layers of black and white film. At the moment of exposure, light through the camera lens hits silver halide crystals in the film emulsion, creating an excited chemical state in the crystals termed a latent image. During development, the exposed silver halide crystals – latent image – grow rapidly into dense clumps of black silver.

Where there was a lot of light, we have a lot of silver; where there was little light, we have less developed silver, and thus an image is formed by different amounts of silver distributed throughout the frame in relation to the amount of light that hit the film.

In black and white film this is the full story, but in color film there is a twist to this process. Color film (negative and transparency) has at least three different layers of silver halide suspended in the emulsion. Through a system of filters and sensitizers, the manufacturer creates silver halide layers that react to a third of the spectrum each. Each layer is sensitive to the red, green or blue part of the spectrum. This is the fundamental trichromatic theory of color that states that you can create any of the colors you want by the addition of varying amounts of red, green and blue light.

In color film, dye coupler molecules are suspended in the emulsion near the silver halide crystals. During development, the silver halide gets developed and the by-products of this (essentially monochrome) development trigger the dye coupler molecules and turn them into colorful dye clouds. After development the unused silver halide and the unused dye couplers are removed from the emulsion. This is a very simplified description of what is actually a very complex process. For example, manufacturers may use sophisticated techniques, such as special chemicals, to ensure the color chemistry stays within each layer or corrects for imperfect spectral absorptions of each dye layer.

So we see that black and white and color chemistry are very similar; color film consists essentially of three black and white film layers. This similarity is exploited in films such as Ilford’s XP2, which is a fine grain, black and white film processed in C-41 type processing chemicals alongside color negative films.

Kodachrome Secrets

There are a few technical secrets behind Kodachrome’s success. Kodachrome was always only available at lower speeds, usually 25 and 64 ASA, thus it was a fine grain emulsion. The smaller grain captured less light, thus the film was slower, but the small silver halide grain did not show up during enlargement. Kodachrome was slide film, so we shot and processed and viewed the same piece of film, unlike negative stock where there are two generations, a negative and a print.

Finally, the biggest advantage of Kodachrome is due to its “non- substantive” film type. A big difference between normal transparency film and Kodachrome is that Kodachrome has no dye couplers incorporated into the emulsion layers. Unlike all other color films of the time, the color couplers were contained within the processing baths. The dye couplers are only introduced during the processing stage of development, in the development

process called K-14. Due to this lack of in-situ couplers, the emulsion layers are thinner, causing less light scattering, allowing sharper results. This unique solution meant that Kodachrome was a lot slimmer and sharper than other slide film. On the downside, it also meant that Kodachrome needed special processing, and so was not compatible with E-6 systems—one of the major reasons for its imminent extinction.

George Eastman House

The last batches of Kodachrome film have been sent to the famous Kodak historical archive and repository—The George Eastman House International Museum of Photography and Film in Rochester, NY. The museum is located alongside George Eastman’s colonial revival mansion and is the house where George Eastman lived before taking his own life by gunshot in 1932. The George Eastman House is the world’s oldest photography museum, with a mission to collect, preserve, and present the history of photography and film. The original collections included the Medicus collection of Civil War photographs, Eastman Kodak Company’s historical collection, and the massive Gabriel Cromer collection. The Eastman Kodak Company has been a major benefactor to the house and museum. If you are in the Rochester area, this historical site is well worth a visit—try to guess the combination of the large safe that is still there after all these years.

The George Eastman House Museum of Photography and Film, is part of the Ryerson University photographic research program. Today, the George Eastman house is the repository for the last Kodachrome film batch.

Photographic Preservation and Collections Management

A unique educational program developed by Ryerson University in Toronto and the George Eastman House is a post-graduate MA degree in Photographic Preservation and Collections Management. Paul Sergeant is studying in this program and is spending a year at the George Eastman House in Rochester. The program’s curriculum is specially designed to deepen students’ understanding of the history of the photographic medium, particularly its social, cultural, and instrumental uses, and the purposes and functions of photographs and photographic collections. The intensive, two-year program deals with the materials of photography, historical film processes, preservation and storage of film and the socio-cultural context of photographs in the last 150 years.

Kodachrome Today

Interest in slide film and the home slide projector started to wane from 1980 onward. Strong competition from Fujifilm Velvia and Provia further damaged Kodak’s market share. Finally with the widespread use of digital cameras, Apple Aperture, Adobe Lightroom, Photoshop Camera RAW, Kodak had to give in. Kodachrome products were gradually discontinued, and on June 22, 2009, Kodak announced Kodachrome would no longer be manufactured. Today, Kodachrome represents just a fraction of 1% of Kodak’s total sales of still- picture films.

We have noted that Kodachrome needs special processing. As stocks of this film slowly dwindle, there is only one processing facility left, Dwayne’s Photo(www.dwaynesphoto.com) in Kansas who have committed to continue to process Kodachrome films through the end of December 2010.

As part of a tribute to Kodachrome film, Kodak will donate the last rolls of the film to the George Eastman House. Steve McCurry will shoot those last rolls and the images will be donated to the museum. Today the legacy of this great film lives on via internet sites such as the kodachromeproject.com and A Tribute to KODACHROME: A Photography Icon, a great site on Kodak.com.

Although Kodachrome has very distinct characteristics and no film will give the exact same results, current users are encouraged to try other Kodak films. Kodak (surprisingly) continues to bring other new film products to market; see for example Review: Kodak Ektar 100 Color Film, PHOTO Techniques, May/June 2009.

Kodachrome was more than just a slide film–the images and messages captured on this medium will inform, amaze and resonate with audiences for many years to come – but of course we will be looking at scanned versions of those masterpieces.

About the Authors

Abhay Sharma
Dr. Abhay Sharma is Program Chair of the Photographic Preservation and Collections Management program at Ryerson University, Toronto, Canada.
Paul Sergeant
Paul Sergeant studied at the Ontario College of Art & Design where he was the recipient of the prestigious photographic art medal in 2006. He has his Master’s in Photographic Preservation and Collections Management from Ryerson University. This allowed Paul the opportunity to study and work at the George Eastman House International Museum of Photography and Film, in Rochester, NY. He is a founding member of the Tintype Studio, a Toronto basedteamofwet-platecollodionphotographers. Paul is also the Archive and Print Manager for Canadian photographer Edward Burtynsky. tintypestudio.tumblr.com