History of photographic lens design
[citation needed] The early photographic experiments of Thomas Wedgwood, Nicéphore Niépce, Henry Fox Talbot, and Louis Daguerre all used simple single-element convex lenses.
Chevalier reversed the lens (originally designed as a telescope objective) to produce a much flatter image plane and modified the achromat to bring the blue end of the spectrum to a sharper focus.
[1]: 27–28 [2]: 158 The lens had the reverse concave flint glass side facing the subject and an f/16 aperture stop at its radius of curvature, making it reasonably sharp over a wide field of about 50°.
[2]: 158 Reversing the lens did increase chromatic aberration, but this fault could be lessened by adjusting the achromat to bring colors at the blue end of the spectrum into focus to match the blue-sensitive nature of the photographic emulsion.
Joseph Petzval (of modern Slovakia) was a mathematics professor with no optical physics experience, but, with the aid of several human computers of the Austro-Hungarian army, he took up the challenge of producing a lens fast enough for a daguerreotype portrait.
Charles Harrison and Joseph Schnitzer's Globe had a symmetric four-element formula; the name refers to the consideration that if the two outer surfaces were continued and then joined, they would form a sphere.
For example, the oblique cos4θ light falloff, sometimes called natural vignetting,[15][16] and lateral magnification and perspective distortions seen in wide angle lenses are really geometric effects of projecting three-dimensional objects down into two-dimensional images, not physical defects.
By coincidence, John Dallmeyer's Rapid-Rectilinear and Adolph Steinheil's Aplanat had virtually identical symmetric four-element formulae, arrived at almost simultaneously in 1866, all of which corrected most optical aberrations, except for spherical and field curvature, to f/8.
Nevertheless, the earliest lenses did not have adjustable stops: their small working apertures and the lack of sensitivity of the daguerreotype process meant that exposure times were measured in many minutes.
[1]: 82–83 The Protar is considered the first "modern" lens, because it had an asymmetric formula allowed by the new design freedom opened up by newly available barium oxide, crown optical glasses.
[25] However, such lenses require correcting for higher ordered aberrations than the original seven[26] with rare earth (lanthanum oxide) or fluorite (calcium fluoride) glasses of very high refractive index and/or very low dispersion of mid-twentieth century invention.
[43] With anastigmat image quality achieved, attention next turned to increasing aperture size to allow photography in lower light or with faster shutter speeds.
The current design can be traced back to 1895, when Paul Rudolph of Carl Zeiss Jena used cemented doublets as the central lenses to correct for chromatic aberration.
Robin Hill intended it to be pointed straight up to take 360° azimuth barrel distorted hemispheric sky images for scientific cloud cover studies.
For example, Nippon Kogaku always apologetically acknowledged that Takashi Higuchi's Zoom-Nikkor Auto 43-86mm f/3.5, the first popular zoom lens, did not meet its normal image quality standards.
The fourteen element/eleven group Kiron was first 35mm SLR zoom lens to extend from standard wide angle to long telephoto (sometimes referred to as "superzoom"),[116] able to replace 28, 35, 50, 85, 105, 135 and 200mm prime lenses, albeit restricted to a small variable maximum aperture to keep size, weight and cost within reason (129×75 mm, 840 g, 72mm filter, US$359 list).
Despite their many image quality compromises, convenient wide range zoom lenses (sometimes with ratios over 10 to 1 and four or five independently moving cells) became common on amateur level 35mm SLRs by the late 1990s.
[126] Like the Kiron 28-210mm, the twelve element/eight group/three cell Tokina had a small variable maximum aperture, but added low dispersion glass and a new bidirectional nonlinear zooming action, to bring size and weight down to an absolute minimum.
Germany had been the optical leader for a century, but the Germans turned very conservative after World War II; failing to achieve unity of purpose, innovate or respond to market conditions.
After ailing throughout the 1960s, such famous German nameplates as Kilfitt, Leitz, Meyer, Schneider, Steinheil, Voigtländer and Zeiss went bankrupt, were sold off, contracted production to East Asia or became boutique brands in the 1970s.
Traditionally, prime lenses for rigid cameras were focused closer by physically shifting the entire lens toward the object in a helical or rack and pinion mount.
[162] Internal focusing was originally popular in heavyweight, wide-aperture telephoto lenses for professional press, sports and wildlife photographers, because it made their handling easier.
[177] Its Vibration Reduction system could detect and counteract handheld camera/lens unsteadiness, allowing sharp photographs of static subjects at shutter speeds much slower than normally possible without a tripod.
[193] Also in 2004, DxO Labs (France) computer software modules were introduced, loaded with information on specific cameras and lenses, that could correct distortion, vignetting, blur and lateral chromatic aberration of images in post-production.
[1]: 16–17 [200] Lenses with glass elements artificially "single-coated" by vacuum deposition of a very thin layer (approximately 130-140 nanometers)[201] of magnesium or calcium fluoride to suppress surface reflections[202] were invented by Alexander Smakula working for Zeiss in 1935[203][204] and first sold in 1939.
[210] The Double Gauss became the preferred normal lens design in the 1950s with the availability of anti-reflection coating and new generation extra high refractive index rare earth optical glasses.
Minolta (as Chiyoda Kōgaku Seikō) produced the world's first multicoated consumer photographic lens in 1956 for their 'Minolta 35 Model II' rangefinder camera - the Rokkor 3.5 cm f/3.5 - with their patented Achromatic Coating.
A prototype multicoated 5 cm f/1.4 lens was also produced for the discontinued Minolta Sky M-mount rangefinder during its development, though it is not known if the coating was more advanced than that applied to prior lenses.
[221] Today, Fuji's Super EBC, Pentax's Super-SMC and Zeiss' T* are regarded as the most advanced photographic lens coatings available, although technical differences are now negligible between manufactures.
Tōkyō Kōgaku 'UV Topcor' lenses) for increasing or decreasing transmission of certain wavelengths, and other finishing layers such as oleophobic and hydrophobic coatings to make the surface easy to clean.
