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‘Panchro’ has become synonymous with Cooke over the years. A lens family with a long history, much allure and prestige. In this article we trace the origins of this iconic series of optics which has endured for almost a hundred years in a variety of forms including in recent times the Cooke Panchro/i Classic S35 and FF prime lenses along Cooke’s most recent offering – the SP3s.
50mm series I Uncoated Speed Panchro from 1943
1920 – The Cooke Series O Opic
This lens series was designed by Horace William Lee at Taylor, Taylor & Hobson as an update to Cooke’s first entries into the world of cinematography which had began as early as 1905 but with purpose-built cinema optics coming in 1912.
The Series O, also called Opic, lenses had a maximum aperture of f/2.0 and were a direct derivative of the Double Gauss symmetrical design (British Patent 157040A). Made up of six elements in four groups which were nearly symmetrical, except for the larger front element, around a central stop. This larger front element optically magnified the size of the entrance pupil and increased the light gather of the lens making it faster.
Series O, Opic Historical Catalogue Extract
Mid 1920s – Talkies Take Over!
As sync sound became incorporated into motion picture capture in the mid-to-late 1920s a fast aperture speed became increasingly important. Previously, bright carbon arc lamps had been utilised for lighting, but these were no longer useable due to the loud arcing electrodes inside the fixtures. Cinematographers migrated to quieter incandescent tungsten lighting which was significantly lower in intensity (tungsten-halogen bulbs wouldn’t be introduced until 1956).
Furthermore, the frame rate of silent film cameras was between 16 and 18 frames per second but sound production increased the frame rate to 24 which represented a ½ stop of light loss. In short, faster lenses were needed.
1927 saw the release of ‘The Jazz Singer’ (director: Alan Crosland, cinematographer: Hal Mohr ASC) the first feature-length motion picture with both synchronized recorded music and lip-synchronous singing and speech. Taylor, Taylor & Hobson quickly modified the Opic lenses for use on motion picture cameras. Credits for these lenses include Best Picture winner ‘Wings’ (1927, director: William A. Wellman, cinematographer: Harry Perry ASC) and ‘Rasputin and the Empress’ (1932, directors: Richard Boleslawski & Charles Brabin, cinematography: William H. Daniels ASC).
The famous tracking shot from ‘Wings’
1927 – Ultra Speed and Super Speed Panchro
In October 1927 Horace William Lee submitted a patent for a modification to his Opic design (U.S. patent 1779267) which became the Ultra Speed Panchros f/1.4. Amongst other changes, the design included a high-refractive middle element and utilised 12 distinct surface radii. This design would also influence Lee’s 58mm f/1.3 Super Speed Panchro which was released in 1930.
1927 then marks the first time that “panchro” was included in the naming of a lens series. But what does it refer to?
At the dawn of the 20th century, early black and white negative film stocks were sensitive only to a limited range of blue and green wavelengths. This limitation required unique adjustments from cinematographers and makeup artists; for example, red lipstick appeared black, and blonde hair looked dark. Yellow-tinted makeup was necessary to make actors’ skin tones appear correctly.
Cinematographers used coloured filters on the lens to improve how skin tones and red hues were captured and presented. German chemist Hermann Wilhelm Vogel broadened the colour spectrum range a film could capture by adding dyes into the emulsion. This film became known as ‘orthochromatic’. Further developments led to full sensitivity of almost the entire visible light spectrum from violet to red. ‘Panchromatic film’ was born.
Although panchromatic film was available in the early 1900s, Eastman Kodak did not offer it as a regular motion picture film stock until 1922. The first feature film shot entirely on panchromatic stock was ‘The Headless Horseman’ (1922, director: Edward D. Venturini, cinematographer: Ned Van Buren ASC).
While increased light sensitivity was generally seen as an improvement, it also revealed chromatic aberration issues in lenses that hadn’t previously been visible. When a film emulsion isn’t sensitive in green and red wavelengths, a lens that doesn’t correctly focus those colours the same as blue wavelengths, for example, doesn’t present much of a problem. But when the emulsion is sensitive to more wavelengths of light – even being a black and white stock – a lens’ chromatic aberration can lead to lack of sharpness in the image.
So, with the emergence of these Panchromatic stocks and anticipating the coming of colour film, correcting these aberrations became crucial. Cooke designer Horace William Lee made sure then that the first series of Panchro lenses performed significantly better with Panchromatic film than what had come before. The name most likely reflects the film these lenses were designed to compliment.
1930s – Uncoated Cooke Speed Panchro
By 1930 Lee had updated his Opic designs and began to create the ‘Speed Panchro’ lens line specifically for cinematographic applications (U.S. patent 1955591A). An advertisement for these lenses ran in the November 1930 edition of The International Photographer and December 1930 edition of American Cinematographer. The lens designs reflected all Lee had learned in making the Opic and Ultra Speed lenses.
Speed-Panchro Advertisement in ‘The International Photographer’, November 1930
This non-coated range was made up of 13 lenses ranging from 24mm to 121mm with an aperture of f/2.0 across the series. It’s worth noting however that without any coatings the effective T-stop would not have reached close to T2.
Uncoated Speed Panchro credits include Best Picture Winner ‘Cavalcade’ (1933, d. Frank Lloyd, cine. Ernest Palmer ASC), ‘Going Hollywood’ (1933, d. Raoul Walsh, cine. George J. Folsey ASC) and ‘Treasure Island’ (1934, d. Victor Fleming, cine. Clyde De Vienna, Ray June ASC and Harold Rosson ASC)
In 1935, Metro-Goldwyn-Mayer’s resident director of photography and three-time American Society of Cinematographers president John Arnold ASC was credited in an advertisement as stating “All of our productions are made with Taylor-Hobson Cooke lenses, and at least 50% of our productions are made with Speed Panchros.”
1947 – Cooke Begin Using Lens Coatings
By the late 1930s the Taylor brothers of Taylor, Taylor & Hobson had both passed and in 1945 the renamed Taylor-Hobson became a subsidiary of the Rank organisation. In 1947 Taylor-Hobson began integrating coatings onto their lenses at the factory. The production of Speed Panchros continued during this transition and lenses with the coatings and transmission stop markings became known as the Coated Cooke Speed Panchros (Series I). Owners and rental houses had the option to send their uncoated lenses back to the factory for coatings and T-stop markings to be applied.
Whilst the uncoated Speed Panchros had only gone as wide as 24mm, Taylor-Hobson had also begun using various rare earth elements in the glass compositions to obtain high refractive indices. This enabled the creation of a 18mm Speed Panchro T2.0 to expand the focal length range. The 8 lens coated set then, covered from 18mm to 100mm with most lenses achieving a wide open T stop of T2.3.
Historical credits that used these coated Series I lenses include ‘Johnny Belinda’ (1948, d. Jean Negulesco, cine. Ted McCord ASC) and ‘Act of Violence’ (1949, d. Fred Zinnemann, cine. Robert Surtees, ASC). In much more recent years sections of ‘Her’ (2013, d. Spike Jones, cine. Hoyte Van Hoytema ASC FSF NSC) also used this historical lens set.
1953 – Series II Speed Panchros (S2s) and Thorium Dioxide
The aptly named lens designer Gordon Cook began working at Taylor-Hobson in 1948 and embarked on redesigning the Speed Panchro line. In 1953 the 25mm T2.2 was released and by 1958 a complete set of the Series II was available from 25mm to 100mm with stops from T2.2 to T2.8.
32mm T2.3 Cooke Speed Panchro series II
The Series II lenses shared much of the DNA of the original Panchro lineage but there was more inclusion of rare-earth glasses and new coating techniques to minimise reflections and increase contrast/transmission performance. Thorium dioxide was added to a silica mixture and helped create glass with high refraction and low dispersion which was massively beneficial in removing chromatic aberration.
This ionizing radiation created “colour centres” on the glass – areas that absorbed some wavelengths of light instead of just passing them through and over time this resulted in a colour cast. Usually this presented itself as a yellow/brownish colour that looked like a tea stain, especially towards the centre of the glass. The 75mm S2 was particularly susceptible to this.
The S2s also marked a transition point from hand-calculations for the optical design of each lens, which could take as long as a year to perfect, to computer aided calculations – albeit on massive computers – which only took days to complete. These lenses also covered the full negative area of 18.63mm x 24.89mm, which was very close to what would become known as Super35.
In 1959, as a compliment to this lens set, the Cooke Telepanchros were released – a 5 way lens set covering from 152mm all the way up to 558mm with T-stops from T2.3 to T6.2
1959 – Series III Speed Panchros (S3s)
Peter A. Merigold designed the Series III lenses. This update covered just two focal lengths – the 18mm Series I was bought up to date with a redesign and the 25mm was upgraded. Both lenses were rated at T2.2 and were some of the first cine lenses to use aspheric optics in their designs. The use of an aspheric surface greatly increased aberration correction in these new lenses whilst also allowing for a decrease in complexity of the optics, thereby reducing the physical size of the lens.
Series II and Series III sets quickly became intermixed with the latter covering the wider end of the focal length range. Over the decades that ensued hundreds of titles were filmed on this combination and they became very popular candidates for lens rehousing.
2010s Onwards – The Rise of Digital Cinema and the Return of Speed Panchro
The rise of digital cinema capture led to a demand for vintage cinema lenses from the late 2010s onwards. Whilst Speed Panchro Series II and III had been rehoused over the years the results had been mixed and the colour cast issues around the thorium dioxide coatings were a cause of frustration for some cinematographers. In 2016 Cooke Optics announced plans to resurrect the famous Speed Panchro line of lenses but recreated with modern glasses and optomechanical designs.
These newer recreations are based on the original optical designs and support a matched 12-way lens set with maximum aperture of T2.2 and include a 65mm Macro. They also have Cooke’s /i Technology and can cover either Super35mm or full frame. In a future article we’ll expand on recreating this iconic look in the modern day supported by an interview with current Cooke Optics Optical Designer Graham Cassely.
Along with the Cooke archive much of the lens history presented in this article was supported by research from ‘The Cine Lens Manual’ written by Jay Holben and Christopher Probst ASC. More information about the history of Cooke lens design is available in this book and Cooke spoke with the authors about this incredible volume. https://cookeoptics.com/news-and-events/behind-the-cine-lens-manual/
