APO-Telyt-R 400 mm f:2,8

Características

Código - 11 256, 11 260 LLC - 196
Producción - 1992-1996 < 390 Objetivos

Variantes:
Montura - LEICA R
Ángulo de visión (diagonal, horizontal, vertical):
Diseño Óptico:
Número de lentes/grupos 11/9
Longitud focal efectiva - 400 mm
Posición de la pupila de entrada
Intervalo de enfoque: - 4,7 m a infinito, dispone de preselección de enfoque
Escalas: en metros y pies
Campo visual mínimo:
Factor de reproducción: 1:11,6
Diafragma - f:2,8-f:22 automático
Montura de filtros: Series 5.5
Parasol: 12545
Accesorios: Correa #14311 y caja de aluminio #14584 incluidos en el paquete.
Longitud hasta la bayoneta - 365 mm
Diámetro máximo - 166 mm
Material: Aluminio anodizado y pintado
Peso - aprox. 5800 g
Inscripción APO-TELYT-R 1:2.8/400
Diseño: Lothar Kölsch - 1991


Referencias




El prototipo de este objetivo (20 unidades) se empleó en los Juegos Olímpicos de Seul, en 1988. Con cambos importantes el objetivo entró en producción en 1992. Está relacionado ocn el Apo-Telyt-R 280 mm f:2.8 y comparten muchas características. There is again internal focusing. The lens focuses past infinity, not for focusing adjustments, but as a way to accommodate the expansion of the glass in hot environments.

The 2.8/400mm is a markedly improved design with increased performance, when compared to the telescope lenses. The focal length of 400mm does enlarge the residual chromatic errors a bit more and that is visible. Overall the performance of the 2.8/280 and the 2.8/400 are quite close. And in absolute terms, the 2.8/400 is an excellent lens. At full aperture overall contrast is high (a necessary condition for a long focus lens); vignetting is about 1 stop. Generally we may note that the newer long focus lenses exhibit a level of image quality that is extremely high and surpasses that of the wider angle/wider aperture lenses with ease. We should remember however that these long focus lenses ‘cheat’ a bit as they have a larger magnification that brings in more detail to the unaided eye of the observer, who will assume that the lens does capture more detail, which is not true. Still, the 180 to 400mm lenses for the R-system were a revelation and are still desirable objects.

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