LensFever

Table Of Contents ✓ Preface In 1983, British lens designer Harold Dennis Taylor (1862–1943) (hereafter “Taylor”) designed a 3-element lens consisting of two convex lenses and a concave lens (Cooke Triplet)[1], opening a new page in modern design of photographic lenses. Cooke Triplet Patent US568052 (includes variation) Features of the Cooke Triplet lens The triplet designed by Taylor are arranged in order of postive – negative – postitive. The focal power of the negative lens must be more or less equals to the focal power of the two postive lenses. The triplet has enough degrees of freedom for the lens designer to correct monochromatic aberrations(spherical, coma, astigmatism, field curvature) and chromatic aberrations(axial and lateral). Alternatively, apart from the simplest three-element design, the lens designer can replace any of the element with a glue doublet or splitting any of the element into multiple elements. Brit. Pat. 22,607 When Taylor published his des