This means that it is often possible to use less glass than a conventional dioptric lens design. Using less glass allows the a long focal length mirror lens to be lighter than a conventional dioptric lens. By reflecting light from front to back, mirrors allow for a compact design. Compact relatively light lenses are easier to carry and to hand hold. Mirror lenses can achieve close focus without a significant increase in complexity.
Minimum focusing distances of less than two meters are common allowing "macro like" photographs. Using a tripod in conjunction with a live view on the LCD, is a good way to create sharp images in low light. Zooming into the live view lets the photographer evaluate the focus precisely. The technique is a little like ground glass focusing of a large format view camera. With in camera image stabilization a mirror lens can be a "walking around" lens.
Because the angle of view is approximates human foveal vision, composition is surprisingly easy: The light caught my eye and all I needed to do was lift the camera and shoot from about 10m. The long focal length allows filling the frame while maintaining a significant working distance between the photographer and subject. This is useful when proximity might change the subjects behavior.
The distance provides a flatter angle than a close up with a shorter lens. Relatively close focus provides macro-like photographs from working distances significantly greater than are typical when shooting with traditional macro lenses. This makes it easier for the photographer to avoid "standing in their own light" and casting shadows on the subject. In general, a mirror lens offers and opportunity to show the world in a unique way. I had climbed half way up a narrow open fire tower to shoot a sunset. The compactness of the mirror lens meant it was on my camera and the camera was on a strap around my neck.
I saw movement on the boat well over a kilometer away. It took a couple of seconds to focus and shoot. The movement was pulling anchor. The shot is the person returning to their seat and ten seconds later the shot was gone. The boat shot defines the big reason to consider a mirror lens. I could not have climbed the tower with a conventional dioptric mm lens on my camera and my camera strapped around my neck.
In the time it would take to unpack a conventional lens the shot would have been gone. The choice is not usually between a mirror lens and a conventional lens. It is between the opportunity to take shots that are not practical otherwise and no opportunity. The bulk and size of a conventional dioptric mm lens means I might not have brought on the hike to the fire tower and the climb up it.
Lightweight and compact, putting the mirror lens in my bag is not a particularly tough decision. It comes down mostly to weather. For a mirrorless camera like the Sony A, older conventional dioptric lenses are alternatives to a new mm mirror lens. There are many very good mm manual focus lenses with an f4 aperture that can be mounted with an adapter for a price similar to that of a new mirror lens.
They will most likely provide better optical quality at mm at the expense of size and weight. The high Tstop of mirror lenses require more attention to the quality of light than might be required with other wider lenses. The constraints of mirror lenses reward the type of attention that translates to all other images.
If nothing else, shooting a mirror lens will surface flaws in photographic technique, image planning, and the process of producing images. Some photographers may consider this a feature not a bug. An overview of image stabilization current in Mainly that the overriding concern for the current makers of most photographic mirror lenses is low cost and ease of design.
The main purpose these makers produce mirror telephoto camera lenses, rather than conventional refractive lenses, is to make them much more cheaply and compact than a conventional refractive lens can be produced. This is easiest to accomplish by coating the back side of a negative meniscus lens known as a Mangin mirror instead of creating a parabolic first surface mirror that would need to be shaped and coated in a way that is more expensive to produce and would also require correction for spherical aberration.
By coating the back of the meniscus lens the light passing twice through the same lens is corrected by the glass of the mirror itself. Mangin mirrors were first created for use as catadioptric reflectors in searchlights. They yield better searchlight performance and and are less expensive to make than the front coated parabolic reflectors they replaced. The emphasis on ease of design and low manufacturing cost results in mirror lenses that often demonstrate poor contrast , fixed apertures , and generally lower acutance than their more expensive refractive counterparts.
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By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service , privacy policy and cookie policy , and that your continued use of the website is subject to these policies. Home Questions Tags Users Unanswered. What's so bad about a mirror lens? What are these lenses good at? In which cases are they limited? Can they collect more light in spite of a similar aperture? Brandon Dube 2, 7 Why do mirrors give less sharpness, gamut, and contrast than lenses?
Why do mirror lenses have poor contrast? Why do old-school catadioptric lenses have a fixed aperture? With an adapter these can be mounted on a Sony A The mirror lenses you are considering require an adapter anyway.
Vivitar Solid Glass Mirror Lenses eBook: David Barth: theranchhands.com: Kindle Store
Annular shape to bokeh due to doughnut-shaped entrance "pupil" Prime only - no zoom lenses See this for more information. They have a fixed aperture, so it would not be possible to collect more light. I've been eyeing one myself, mostly for moon shots, and possible use for the donut bokeh. Calyth 1 Challenges with long focal length lenses Shooting long focal length lenses is can present challenges that may be at odds with a photographer's expectations. Technical challenges of mirror lenses Manual focus is more challenging than autofocus. Technical advantages of a mirror lens The mirrors can be very thin.
Shooting a Mirror Lens Using a tripod in conjunction with a live view on the LCD, is a good way to create sharp images in low light. Remarks The boat shot defines the big reason to consider a mirror lens.
So if Zeiss or anyone else doesn't supply a lens with a lens collar or a way to use a lens collar it means they don't intend for their lenses to ever be used on a tripod? It couldn't possibly have anything to do with the fact that the lens is light and compact enough to not require a lens collar to be used with a tripod, could it? Since many large, bulky cinema lenses don't come with a tripod collar I guess you think those lenses aren't intended to be used with mechanical support either? Michael C k 7 Sign up or log in Sign up using Google. Sign up using Facebook.
Sign up using Email and Password. A safety catch holds the lens securely during rotation. One more unique feature of the Vivitar Series I mm f8 solid catadioptric lens is its development and manufacture entirely by U. 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 mm f8 is the first of a family of solid catadioptric lenses, with mm f11 and mm f1 1 versions scheduled to follow. The production of Series I solid catadioptric lenses, including the mm f8 is an exacting, time-consuming process. Optics of this type do not lend themselves to automated, assembly-line manufacture.
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. Screw-in hood, detachable tripod socket, filters, lens case , front and rear lens caps included. 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. 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. Look for a 90mm f2. 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. According to KEH, the lens was originally created for the U. Other sources originally at Solid Cat - Luminous Landscape with comparisons further indicate. It made the speeds rather slow for handholding, as I found out. One factor is probably enhanced contrast from the lack of air-surface loss. That's a descendant of the original "FatCat"! It was originally designed and built for the U.
Product description
Scroll down to the description, some interesting info there on these unique bits of glass. Rarest Solid Cat Camera Lens! I have no lens cap for this one. It looks like the original was a "push-on" mm. I got a pinch lens cap in mm, but it is too large by just a little. ALSO note that this original Vivitar company has nothing but the name in common with the current company marketing under the name Vivitar and Series 1.
Vivitar Series 1 800mm f/11 Solid Cat mirror lens
Great stuff, JDM ; I've not come across this fascinating lens before. A great find and an excellent write-up; thanks for your efforts. Looks like a fun lens. Mike Gammill , Aug 25, I'd never run across it either, thanks!
Sandy Vongries , Aug 25, Oh, one more of my older posts: JDMvW , Aug 29,