|1890s : Cooke Triplet|
As optical manager of T. Cooke & Sons of York, makers of astronomical telescopes, H. Dennis Taylor attempted to eliminate the optical distortion or aberration at the outer edge of lenses. In 1893 he designed and patented the revolutionary, and now famous, triplet design (British patent no. 1991). The Cooke Triplet concept was a simple and elegant solution to design issues that plagued lens designers of the era.
Dennis Taylor was understandably excited about his development, and on 7th September, 1893 wrote a letter to Taylor, Taylor & Hobson, enclosing a photo of York Minster taken with "a trial lens constructed on my new principle, having a equivalent focal length of 7 1/4 inches. The exposure was made on an Edward’s Landscape Plate (Slow) and with a stop equal to F/7.7 (by careful measurement)."
He goes on to say: " You will see that the Minster wants a decidedly wide angle to get it all in, consequently I had to raise the rising front by 1 1/2 inches so that the lens is tried more severely than if used centrally opposite a 7 1/2 x 5 plate which size it is manufactured for. On submitting this print (or rather the negative) to an experienced amateur photographer, after looking carefully at it and without my asking, he said that if he had been using a 7 1/4 Ross Portable Symmetrical or other lens of such type, he would not expect to get so good a result without having to stop down to F/32, a conclusion which I had myself independently arrived at."
Having no desire to enter the photographic lens business, T. Cooke & Sons offered the manufacturing rights to Taylor, Taylor & Hobson of Leicester, optical instrument makers who had a reputation for producing quality optical products since 1886 when William Taylor founded the company in Leicester with his brother, Thomas Smithies Taylor. William Taylor's philosophy: "Don't do what everyone else can do; go out for something new," coined in 1886 holds true at Cooke Optics today.
The first Cooke photographic lens was made by TT&H in 1894 based on Dennis Taylor’s Cooke Triplet patent of 1893. (There is no familial relationship amongst Dennis Taylor and brothers William and Thomas.). TT&H went on to produce subsequent lens designs by Dennis Taylor through Series V. The licensing agreement stated that the lenses would be sold under the trade name "Cooke". The very first lenses made were brass and included the inscription "H.D. Taylor's patents."
Cutaway cross-section of Early Cooke lens of Cooke Triplet design offering critically fine definition right up to the margins of the photographic plates.
In 1895, the Cooke lens was awarded the only medal of the "Royal Photographic Society given for improvements in lenses within recent times."
The TT&H Cooke lens catalog of 1897 states:
"Lack of sharp definition at the margins, and blackness and lack of detail in the shadows, are among the commonest defects of photographs. The introduction of lenses which, without the use of stops, yield definition uniformly fine throughout their plates, marks quite a new era in photography."
Today, triplets of various kinds are used almost universally for lenses of intermediate aperture sold on smaller still cameras.
This was the beginning of a legacy of superior and innovative lens design and manufacture under the Cooke name that continued throughout the 20th century beginning with still portrait, telephoto and process lenses, through the development of acclaimed Cooke cine and television lenses, and continues today by Cooke Optics Limited, with award-winning 35mm cine prime and zoom lenses.