Chromatic aberration

Iris diaphragm definition: a composite diaphragm with a central aperture readily adjustable for size, used to regulate the amount of light admitted to a ...

The world's most fashionable prescription glasses online. Our prescription lenses are made in USA. Manufactured & shipped in a week.

Optolens

But in the Series I solid catadioptric lens fall-off has been reduced to less than 30%, the equivalent of about 112 .f stop. As with all mirror telephoto lenses, the Vivitar Series I 600mm f8 is a fixed aperture lens. Exposure is controlled by camera shutter speed and the use of neutral density filters. In this lens, filters are placed behind the lens in the T-mount, thus allowing the use. of smaller Series I 35.5mm close tolerance VMC filters. The lens focuses very quickly, since the entire main body of the lens (with primary and secondary mirrors including the afocal double) moves relative to the elements forming the Barlow group which remains at a fixed distance from the film plane. This focusing system requires about one-fourth as much axial travel as would be required if the entire optical system moved as a single unit. The lens can be rotated 360° inside its tripod mounting ring and can be locked in any position. A safety catch holds the lens securely during rotation. One more unique feature of the Vivitar Series I 600mm f8 solid catadioptric lens is its development and manufacture entirely by U.S. sources. Working with the Perkin-Elmer Corporation, a world leader in global science and astronomical systems, Vivitar has incorporated the principles of intricate astronomical optics into photographic lenses for the professional and advanced amateur in 35mm photography. The 600mm f8 is the first of a family of solid catadioptric lenses, with 800mm f11 and 1200mm f1 1 versions scheduled to follow. The production of Series I solid catadioptric lenses, including the 600mm f8 is an exacting, time-consuming process. Optics of this type do not lend themselves to automated, assembly-line manufacture.

This lens represents three major advances in catadioptric lens design. it offers the photographer extreme compactness, inherent environmental stability, and superior relative illumination; characteristics that have until now been unattainable in long focal length reflex lens for 35mm photography. The optical design of the aspherical 600mm solid catadioptric lens is derived from the Cassegrain telescope objective used extensively in astronomical work. The extreme Series I 600mm so lid catadioptriC lens compactness of this lens is attributed to the achievement of a seven-to-one ratio between focal length and barrel length. This compares with a 1.2 to 1 ratio for traditional non-mirror telephoto lenses and about four-to-one for previous reflex lenses. The short physical length of this lens helps to lessen the effect of minor in-camera vibrations such as mirror bounce on image sharpness. Highly acceptable hand-held shots at relatively slow shutter speeds are entirely possible. The photographer can safely violate the rule for normal telephoto lenses that minimum shutter speed should approximate focal length in hand held shooting. (A 600mm lens would require 1/500 second or faster shutter speed.) Stability has been another major problem in catadioptric lenses. In conventional designs, the optical ] groups of the lens are separated by large air spaces. Temperature variants often create serious optical alignment anomalies, decreasing sharpness. These lenses are also susceptible to severe mis-alignment caused by minor shocks and vibrations. In the 600mm f8, spherically shaped elements are pieced together to form what is a virtually solid element. As all the optical elements share similar temperature coefficients, the lens is temperature stable even in extreme climates. This near-solid construction also makes the optical alignment highly resistant to damage from impact. The troublesome "hot spot" present in conventional mirror lenses is almost entirely absent in the Vivi tar Series I 600mm. This " hot spot" results from a difference in illumination between axis and corner of 50% or more.

Catadioptric

They are produced individually, each lens being assembled and tested almost as though it were the first one to be built. For this reason, these lenses will be in limited supply. Optical Specifications Construction: 9 elements 7 groups Angle of acceptance: 4° Minimum focusing distance: 7 meters (23 feet) Aperture range: f8 (fixed f stop) Mechanical Specifications Length: 8.4cm (3-5/ 16 in.) Weight 1.36kg (3 lbs) Diameter: 1 0.6cm (4-3/16 in.) Filter provision : 35.5mm at the rear of the lens, inside the T-mount . Filters included are Series I VMC close tolerance UV haze, K2, 4X NO, and 25A. Screw-in hood, detachable tripod socket, filters, lens case , front and rear lens caps included. Mounts available to fit Universal Thread, Nikon/Nikkormat, Canon, Minolta, Konica Autoreflex and Olympus OM cameras. Vivitar Series I Program In recent years, remarkable progress has been made in solving some of the classic problems of optical design. Intensive work in the field was spurred on by the demands of space exploration and military applications and vastly aided by the growing sophistication of computer technology. Vivitar optical designers, working with programs devised for highly specialized optical tasks, have used computer generated designs to develop for Vivitar a new series of lenses capable of performance unreachable until now. Each Vivitar Series I lens so far introduced represents a breakthrough in optical design . The 135mm f2.3 and the 200mm f3 are among the fastest automatic telephoto lenses in their respective focal lengths. They are unusually light and compact. Each has a uniquely positioned rear compensating element that automatically corrects aberrations at all points from the closest focusing point to infinity. The 70-210 f3.5 automatic zoom lens and the 35-85mm f2.8 auto variable focusing lens are likewise definite advances in lens design, both offering extremely close focusing capability and remarkably compact configuration. To come? Look for a 90mm f2.5 macro, a 28mm f1.9 wide angle, 800mm f1 1 solid catadioptric and 1200mm f1 1 solid catadioptric telephoto .tenses. There will eventually be a complete optical system of more than twenty Vivitar Series I lenses, each representative of advanced technology and demonstrably superior to other lenses currently available. Vivitar marketed in the U.SA by Ponder &Best, Inc. Corporate Offices: 1630 Stewart St., Santa Monica, CA 90406 In Canada: Precision Cameras

Description as found at https://www.photo.net/forums/topic/509542-vivitar-series-1-600mm-f8-solid-catadioptric-telephoto-lens/:

The HEUFT InLine II IR carries out an optical complete inspection of the bottle base in order to detect foreign objects and defects reliably.

Fresnellens

Accent lighting is mainly achieved with high contrast ratios (the ratio between the light shining on the point of interest and the ambient light). Some common ...

Cassegrain telescope

Kohärenz bezeichnet den Zusammenhang zwischen unterschiedlichen Texteilen. Dieser sollte sich durch die Struktur der Arbeit und die logische ...

Dobsonian telescope

202418 — 55mm is the industry standard back focus length for many optical correctors and reducers, and generally suits most setups, but we always ...

At 1-800 Contacts, we beat any price on contact lenses, plus free, fast shipping and convenient online ordering. We Deliver. You Save™

Illumination Technologies Inc, uses 4 email formats: 1. last@illuminationtech.com (63.3%). Enter a name to find & verify an email >>>

Algori 360 Image. By Kevin Bazira · Download ... At this point, you can adjust your image's dimensions (width and height) using the Gutenberg block inspector ...

Come bid on the Blue Bombers themed Christmas Tree at Furniture Plus until November 23rd! 50% of sale proceeds will be donated to Portage Pitbulls Football

For over 30 years, Inspection Perfection provides residential and commercial construction inspections for builders and institutional lenders.