The Sensational Kodak Ektachrome

I recently profiled one of my favorite film stocks: Kodak Ektachrome slide film. The beauty of slide film is that it shares many of the characteristics of motion picture projection film as both categories of film stocks were meant to be projected and they both represent a finished photochemical image. While a negative can look a million different ways as it represents uninterpreted data from a scene (much like a digital log image) and needs to be printed or scanned and digitally prepared for viewing, slide, once developed, gives us a positive image that is ready to be viewed. Profiling a positive (slide or motion picture print) gives the intended look of film with no guesswork and no intermediate steps to bring a Cineon negative scan to the display.

The differences between motion picture print and slide film consist in the contrast curve. They both are meant to be projected but they expect to be projected in different environments. While motion picture print is projected in a very dim environments ( cinema rooms), the contrast curve can gently roll off to allocate more detail in the highlights. Slide film on the contrary needs to be more contrasty around the shoulder area in order to give a good image reproduction in home environments where the luminance levels are higher compared to a cinema room. This can be compensated for digitally to match the contrast curve of a classic cinema print and obtain a super gentle highlight roll off.

The Kodak Ektachrome has been profiled by shooting thousands of color patches under different lighting conditions side by side on film and digital. This yielded 2 datasets, the datasets have then been fed to ColourMatch, my personal color matching algorithm. If you want to see a comparison between ColourMatch and other options available out there I invite you to check this blog post where I showcase the differences between algorithms right on the Kodak Ektachrome dataset.

Here the comparison of digital rec709, true Ektachrome scans and digital with the matching LUT applied.