Cooke Portrait/Soft-Focus Lenses
Clarence White and Alfred Stieglitz, master impressionist photographers, among others, used a Taylor, Taylor & Hobson lens known as "The Rapid View" or "Portrait Lens" (brass lens engraved "R.V.P.") produced by TT&H in the late 1880s. By 1913, because of the influence of these acclaimed photographers, the company received numerous requests for the RVP lens that predated the sharp Cooke Anastigmat. In response to an avalanche of requests, they reproduced the single lens RVP as the "Cooke Achromatic Portrait Lens f/7.5" (as engraved) in four focal lengths: 10.5 inch for 4x5, 12 inch for 5x8, 15 inch for 6.5x8.5 and 18 inch for the 8x10 format. The "new" versions of these lenses included an iris diaphragm.
A Cooke lens catalog of 1913 notes, "Whoever expects sharp definition will be disappointed, but the photographer who desires softness and roundness coupled with fine modeling and a true perspective will be both astonished and delighted."
Subsequently, a series of Cooke Portrait lenses were produced called "Portrics", "Portrellics", and "Portronics", though none were engraved with those names. Instead, they were engraved with their respective series numbers: Series II, f/4.5 (the most popular of the Cooke Portrait lens series which later prompted Series IIB, IIC, IID, and IIE ), Series IIA, f/3.5, and Series VI, f/5.6.
These early soft-focus lenses were sharp anastigmats that employed a diffusion adjustment allowing the photographer to distribute any degree of softness evenly throughout the plate. The most refined way to use these variably-soft lenses is to set the diffusion adjustment first, to give the amount of softness desired over the image, then afterward focus on the part of the subject you want to appear sharpest.