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Thread: 500 mirror lens

  1. #21

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    I would stay away especially from "old" lenses. I am not sure that the mirror coating lasts for decades... not to mention alignment issues and possible astigmatism due to mirror stress.
    "The problem with photography is that it only deals with appearances." Duane Michals

    "A photograph is a secret of a secret. The more it tells you the less you know." Diane Arbus

  2. #22

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    I have a Promaster 500mm cat lens that I bought new back in the mid-90s. It has come in handy a couple times for shots for which a 28-200 isn't long enough. My main issue with these is that they are tricky for ME to focus, because I don't see as well as I used to, and the DOF of a 500mm lens at f/8 is quite thin. When properly focused, they can do a decent job. When it's the difference between getting the shot or not getting the shot, this lens is adequate for the job.
    ME Super

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  3. #23
    AgX
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    Quote Originally Posted by Dali View Post
    I would stay away especially from "old" lenses. I am not sure that the mirror coating lasts for decades... not to mention alignment issues and possible astigmatism due to mirror stress.
    What is the difference between mirror stress and lens stress?

  4. #24

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    Mirror stress is reversed side to side.
    "There are a great many things I am in doubt about at the moment, and I should consider myself favoured if you would kindly enlighten me. Signed, Doubtful, off to Canada." (BJP 1914).

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  5. #25

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    A mirror is thicker than a lens and is more prone to thermal expension/contraction. Being mounted thght in its cell, a mirror will show deformation it is can expend freely.
    "The problem with photography is that it only deals with appearances." Duane Michals

    "A photograph is a secret of a secret. The more it tells you the less you know." Diane Arbus

  6. #26
    AgX
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    A mirror is not neccessarily thikker than a lens, and to my understanding the mass of the element would be decisive.
    (By the way: in a catadioptric lens a mirror and a lens can be formed by one single element.)

  7. #27
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    Russian 500mm f8 MTO mirror lens

    can I add something ? Many years ago now I got a RUSSIAN MTO 500 f8 mirror lens to use for Sport photos, mainly Cricket, for my local newspaper ( which went BROKE in 1980) and it was all B&W film work - I got some good results, many published photos -- it fitted my Screw-thread PENTAXes , ZENITHS, PRAKTICAS, and with a 'P' adaptor my CANON FTBn .
    A ZENITH 'E' showing the wooden box it came with also one of the filters -- it cost me £69-00 from 'Brocks Cameras' ( now gone BROKE!)

    Mirror Lens by pentaxpete, on Flickr
    'Walking on Water' taken with it , PRAKTICA MTL3, expired 'Activa' ( KONICA) 200 film rated 100 ASA

    Walking on Water ! by pentaxpete, on Flickr
    'Doughnut' Rings -- rear car light out of focus, PRAKTICA LB, expired Fuji Press 800 film

    Test 02: Russian MTO 500mm by pentaxpete, on Flickr
    An 'Old Dog still learning New Tricks !

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