By: José Manuel Serrano Esparza

Metaphysical first presentation photograph of Kodachrome films by Kodak Rochester in 1936. Pay attention to the legendary cylindrical metallic tin inside which was protected what for many experts has been and will be the best chemical emulsion for slides of all time.


The fabulous Kodachrome slides were invented in 1936 by two musicians very expert on photography and chemistry called Mannes and Godowsky, with the aim of helping Eastman Kodak in the sales of its 16 mm cinematographic amateur film.
It was the first 35 mm photographic emulsion in the world, together with the German Agfacolor Neu, appeared in an almost simultaneous way.
It must be highlighted the spectacular evolution of Kodachrome films, regarding nominal sensitiveness and its manufacturing process, because for instance during fifties it was a 12 DIN/12 ASA film, this being a period in which the ISO 100 emulsions were deemed very quick.
Historically, Kodachrome changed from the starting K-1 process to the K-12, and it would become worldly consolidated at a worldwide level with the current K-14, its actual cornerstone.
As a matter of fact, Kodachrome films use a unique technology, since they don´t include any colour couplers (as happens in all the slides featuring E-6 process), it being incorporated through the processing chemical components in a proportional way to the exposure received by its different layers of black and white emulsion sensitised for each one of the primary colours. The silver halide image is substituted by crystalline colorants, chemically more resistant than the amorphous ones used in the structure of the emulsions based on chromogenic chemistry.
This very complex technology, requiring the use of very bulky and expensive machinery, has been the alma mater of Kodachrome legend: ultrafine grain, huge resolution ability, superlative acutance and an unbeatable stability before and after the process, with very peculiar palette of colours and tonalities, certainly loved and almost idolized during more than fifty years by the best photographers in the world till currently, and it has been the only chemical emulsion performing as main character of a song (´Kodachrome´, created by Paul Simon in 1972).
It´s incredible that for more than half a century until the nineties decade (which brought about the arrival of Fujichrome Velvia, Kodak Ektachrome 100VS and Fujichrome Provia 100), Kodachrome displayed an indisputable dominance as regards acutance and colour saturation, compared to the rest of slides, and besides it was proved that in some elite graphic magazines, after the photomechanics and in sizes not exceeding 20 x 28 cm, the images transferred to paper from an original Kodachrome 35 mm slide showed a global aesthetic beauty of image superior to those ones obtained from original medium format 6 x 6 cm slides from other brands!
And a myriad of photographers who worked in tropical areas with adverse climatology for the emulsions, verified that Kodachrome slides had wonderful stability properties under such conditions, clearly beating the rest of slides in this respect.
It´s impressive the fact that Kodachrome slides have been extraordinarily well preserved and have kept their brilliant colours almost flawless since the autumn of 1938.
According to tests made by Henry Wilhelm in France in 1988, at 24º C and at 40º C of relative humidity, Kodachrome slides are able to endure 90 years intact until a density loss of 10% appears.
Therefore, it´s decisive the fact that the final Kodachrome image is constituted by molecules of pure dye, introduced during the process and not present in the silver halide emulsion during the exposure time.
And here lies the pith of the question, for Kodachromes are essentially black and white films featuring three layers sensitized for the three basical colours, and during the K-14 and after a specific development for each of the three quoted layers, the colour is added by means of the ´dyeing´ of each one.
It all is awesome, on being reported that compared to the three quoted layers of Kodachrome, Fuji Velvia has 17!
Four have been the Kodachrome flagships:

Here we have the famous little cardboard boxes of Kodachrome film of the second half of thirties and decade of forties and fifties, coinciding with the glorious epoch of cinematographic Technicolor. Because of it, Technicolor became into the reference emulsion for the making of publicity photographs of many of the most wonderful colour movies in all the history of cinema, specially ´Gone with the Wind´.

I even today it is the reference from which other slides are judged. With a RMS factor (index of fine grain) 9, it has been widely used by professionals, due to its very fine and neutral chromatic reproduction.
Superb for landscapes, trees and leaves in various seasons of the year, still lives and all kinds of top-notch reportages with static subjects and very good lighting conditions.
It goes on being the sharpest slide in the world, achieving besides very rich and pure colours.
It´s the second film in the world in terms of fine grain, being only beaten in this trait and through a very narrow margin by Fuji Velvia, though for many experts the unbeatable acutance of Kodachrome 25 allows it to get the upper hand.
It improves Velvia -which is a great feat- regarding resolution capacity.

Its exposure latitude is scarce: between -1/2 and + 1.
Marvellous to make king size enlargements, being probably the historical leader slide followed by Fuji Velvia.
It´s only equivalent in 35 mm negative film has been represented by the wonderful and missed Kodak Ektar 25 Professional.

Publicity photograph made with Kodachrome of Clark gable and Vivian Leigh, the main characters of ´Gone with the Wind´.

Publicity photograph made with Kodachrome of Victor Mature and Hedi Lamarr, the main characters of ´Samson and Delilah´.


Perhaps the most widespread and used. It´s basically a quicker Kodachrome 25, preserving an excellent image quality and very fine grain (RMS 10), only beaten in this aspect by K25 and Velvia.

It features a more versatility of use, thanks to its 1 1/3 more stop of speed.

Its exposure latitude is very small: between -1 and +1/2.

In a lot of batches of Kodachrome 64, it was confirmed that its effective sensitiveness was ISO 80, with the best rendering of greys in the world, followed very closely by Kodachrome 25, hardly something colder.

It was always commercialised the remembered Kodachrome 64 in medium format 120 roll.
Kodachrome 64 is the film displaying more neutral, natural and attractive tones, being an emulsion contributing some more contrast than K25.

Both in Kodachrome 25 and Kodachrome 64, the cyan saturation is high, with a density very suitable for projection, though it makes difficult its transfer to Cibachrome.

Extraordinary portrait of Rhonda Fleming, made with Kodachrome film.

Kodachrome 25, the sharpest and second less grainy slide in all the history of photography, virtually unbeatable until the appearance of Fuji Velvia, though its incredible acutance and aesthetical beauty of the former perhaps won´t ever be superated.


It was the first slide incorporating tabular grain technology.

It´s an utterly sharp film, very fine grain for its sensitiveness and rather beautiful from an aesthetic viewpoint, besides producing very nice and accurate colours, being excellent to capture the chromaticity and tonal ranges of the last hour of the day clouds.

It´s also a superb emulsion for aerial photographs, due to its extra speed over its lower ISO sisters, its sharpness and the very faithful reproduction of colours.


Likewise, it´s very used by people photographers, attaining beautiful skin tones and very good portraits with window light, because of its speed.

It can be uprated up to EI 250 with good results, being very apt both for photographs of animals with supertelelenses and great aperture and for sporting photography, clearly beating the best and typical 400 ISO slides used in this type of tasks, getting enlargements with superior quality and less grain.

It boasts the rich blacks and brilliant Kodachrome colours, bettering in sharpness 200 ISO emulsions like Kodak Ektachrome 200 (which in its turn beats it very slightly in fine grain).

Kodachrome 200 keeps a very high level of quality with the advantages that implies a 8x increase in speed, and besides, its special palette of colours turns out to be superb to introduce Impressionist hues and for the capturing of handheld shots with ambient light and without any blurring, specially with elite great aperture fixed focal lenses and great luminosity.

Kodachrome 200, and extraordinary and very versatile slide, whose high sensitiveness (ISO 200) became it into a high quality choice for many international level nature and sports photographers.


It´s a version balanced for photoflood (a lamp of intensive lighting), balanced for 3400º K, which allows to make photographs boasting Kodachrome quality under this type of luminous source, without correcting filter lowering the effective speed of the film. It´s saturated colours (specially the red ones) attain optimal slides fro projection and its high sharpness and extremely fine grain are quite fit for huge enlargements.

Tree with autumn leaves´. Photo: Rob Sheppard. Kodachrome 25.

´Flowered Landscape´.Photograph made with Kodachrome 64. Notice the great hyperrealistic aesthetical beauty of Kodachrome, less contrasty than more modern films as for instance Fuji Velvia.

© Copyright José Manuel Serrano Esparza