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Achromatic objectives are a typical standard design. In addition to oxide glasses, fluorite lenses are often used in specialty applications. These fluorite or semi-apochromat objectives deal with color better than achromatic objectives. To reduce aberration even further, more complex designs such as apochromat and superachromat objectives are ...
The original two element Gauss was a telescope objective lens consisting of closely spaced positive and negative menisci, invented in 1817 by Carl Friedrich Gauss as an improvement to the Fraunhofer Achromatic telescope objective lens by adding a meniscus lens to its single convex and concave lens design.
An achromatic doublet brings red and blue light to the same focus, and is the earliest example of an achromatic lens. In an achromatic lens, two wavelengths are brought into the same focus, here red and blue. An achromatic lens or achromat is a lens that is designed to limit the effects of chromatic and spherical aberration. Achromatic lenses ...
This was a simple plano-convex or bi-convex lens, or sometimes a combination of lenses. With the development of the modern achromatic objective in 1829, by Joseph Jackson Lister, the need for better condensers became increasingly apparent. By 1837, the use of the achromatic condenser was introduced in France, by Felix Dujardin, and Chevalier.
Achromatic doublets therefore have higher thickness and weight than the equivalent non-chromatic-corrected single lenses. [ 10 ] In comparison to telephoto lenses , shorter focal length objectives benefit less from low-dispersion elements, as their chief problem is spherical aberration rather than chromatic aberration .
Reversed achromatic lens. Charles Chevalier's Paris optical firm produced lenses for both Niépce and Daguerre for their experiments in photography.In 1829 [3] [citation needed], Chevalier created an achromatic lens (a two-element lens made from crown glass and flint glass) to cut down on chromatic aberration for Daguerre's experiments.
Long focus lenses are relatively simple to design, the challenges being comparable to the design of a prime lens. However, as the focal length increases the length of the lens and the size of the objective increase in size and length and weight quickly become significant design issues in retaining utility and practicality for the lens in use.
Detail of the mounting of a Leica IIIf. Currently, Cosina in Japan — many of whose recent products are marketed under the Voigtländer brand — and FED in Ukraine continue to produce camera bodies using a true Leica thread-mount. These give amateurs the rare chance of having a very professional camera by combining a used Leica lens with an ...