KodakKodachrome 64

Kodak Kodachrome 64 was an ISO 64 color slide film for daylight, processed only in Kodak’s K-14 process. It was introduced in 1974 and discontinued in June 2009; the last lab developing it in color, Dwayne’s Photo in Kansas, stopped at the turn of 2011 [4] [3]. Its look can no longer be shot on film: it survives in existing slides, and in imitations such as the Grain Archive style.

Look and color

Kodak itself only wrote that the film “reproduces subtle color naturally” [1]. What follows are photographers’ and analysts’ accounts, often of slides decades old:

• Warm, with strong reds. An RIT author found that Kodachromes “render the world warmer with more red saturation than some Ektachromes”, and that Ektachrome 64 Professional rendered subjects cooler than Kodachrome 64 Professional [7]. Digitising his own 1990s slides, David Hume writes: “The red in the Kodachrome actually is this vivid” [10]. A cinematographer remembers “reds and yellows accentuated” in 16 mm and 1950s–60s Kodachrome [9].
• Blacks and whites. The same account describes “clean white whites and crisp, deep, neutral blacks” [9].
• Skies: blue, sometimes cyan. Simon Foale thought Kodachrome 64 “sometimes had a bit of a cyan cast, especially compared to KM25 and Velvia” [11]; Alex Luyckx found the skies “a perfect blue” and yellows “bright and sunny” [13]. VISNS suggests, as a hypothesis from the red layer’s sensitivity peak near 650 nm, that blue skies were recorded “slightly darker, maybe by ¼ stop”, with a little more cyan dye [8].
• Greens: the sources disagree. VISNS describes “vivid, almost surreal, green foilage” on projected slides [8], and Luyckx sees “Reds and Greens standing out” [13]. We found no written source for the subdued greens often attributed to Kodachrome.
• Accuracy. Foale found the colors “generally were pretty accurate”, with Kodachrome 25 more accurate than 64 [11]. Steve McCurry, who shot the last roll, said Kodachrome “had more poetry in it, a softness, an elegance” [6].
• Why many scans look blue. SilverFast writes that Kodachrome was made with “a light blue cast” to offset the yellowish light of slide projectors, which modern scanners do not have [12]. Luyckx, scanning his own slides, found “little in the way of colour cast” on properly stored ones [13].

Tonality

• Curve. On the datasheet’s characteristic curves, D-min sits near 0.2 and D-max is not reached: the red, green and blue curves are still rising at about 3.7, 3.45 and 3.3 [1]. Our reading of the graph:
  • a slope of about 1.1 in the highlights, 1.7 in the midtones and 1.85 in the shadows, then a gradual descent, with no hard wall;
  • about 5.8 stops between densities 0.3 and 3.0;
  • in the shadows, the red curve sits above the green, and the green above the blue.
• Contrast. The RIT author found Kodachrome “slightly more contrasty” than Ektachrome films [7]. A Cinematography Mailing List member summed it up as “Exremely rich colours, wide tonal range, fine grain” (sic) [9].
• No push. Kodak did not recommend push processing for Kodachrome 25 or 64 [1].
• Long exposures: no correction from 1/10,000 to 1/100 s, +⅓ stop with a CC05R filter at 1/10 s, and exposures of 1 s or longer not recommended [1].
• Tungsten light: EI 16 with an 80A filter at 3200 K, EI 20 with an 80B filter at 3400 K [1].

Grain and sharpness

• Kodak described Kodachrome 25 and 64 as “extremely sharp” with “extremely fine grain” [1]. The figures come from different decades and manufacturers: treat them as roughly comparable only.
• Sharpness: the datasheet gives modulation transfer curves but no resolving power figure [1].

Spectral sensitivity

The blue-sensitive layer peaks near 423 nm and falls steadily, the green-sensitive layer peaks near 552 nm and the red-sensitive layer near 650 nm, both dropping steeply on their long-wavelength side. The curves cross near 497 nm (blue and green) and 583 nm (green and red) [1]. The Grain Archive style is tuned from the reviews above, not computed from these curves [16].

Names, status and history

• 1935 and 1974. Kodachrome, launched in 1935, was the first commercially successful color film. In 1974, with the move to the K-14 process, Kodachrome 25 and 64 replaced Kodachrome II and Kodachrome-X [4] [3].
• A film without couplers. Unlike E-6 and C-41 films, Kodachrome held no dye couplers in its layers: the dyes were added during processing [4]. Kodak called it “a complex film to manufacture and an even more complex film to process” [3].
• Formats. Kodachrome 64 was sold in 135 from 1974 and as a professional 135 film (PKR) from 1983, both until 2009; in 120 from 1986 to 1996; and in 126 and 110 cartridges for some years [4]. The 1996 datasheet lists PKR in 135-36 on a 5.3 mil acetate base [2].
• June 22, 2009. Kodak announced it would retire Kodachrome, which then represented “just a fraction of one percent” of its still-film sales, and suggested Ektachrome E100G and Ektar 100 instead [3]. The June 2009 datasheet adds that there was “no exact replacement” [1].
• The last roll. In July 2010, Dwayne’s Photo developed the last roll of Kodachrome made, shot by Steve McCurry [4] [6].
• End of processing. Dwayne’s Photo in Parsons, Kansas, was the last lab. Its last Kodachrome machine was due to shut down on December 30, 2010 [5]; Wikipedia reports that the last rolls were processed on January 18, 2011 [4]. Kodachrome can no longer be developed in color, only as black and white by some labs [4].
• Datasheet. The last edition, E-55 from June 2009, carries the discontinuance notice; we link a copy hosted by 125px, as Kodak no longer publishes it [1].