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Vivitar series 1 600mm 1.8 catadioptric nasa lens?

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Dub_Digital
Posts: 2793 - Karma: 634
Came across someone selling this lens on craigslist, ive never heard of it and it sounded insane so of course i looked into it, i havent been able to find anything on this lens , wondering if anyone on here knows anything about it? from what i read its somewhat rare, , i found these pics tho, no idea whats even going on, some insight would be legit!

also what does it mean that there's no space in between the elements? and i cant find what kind of mount it is...


Click for larger image

Click for larger image
Dec 6 2011 6:28PM
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TijmenDal
Posts: 4849 - Karma: 1,295
It has the same lens design as a beauty dish or like the lights the dentist uses to beam light into your mouth.

Anyway, I don't expect it to be very high quality. That being said: f/1.8 at 600mm is unreal...
Dec 6 2011 6:42PM
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kalum.ko
Posts: 585 - Karma: 1,672
Just a guess, probaly wrong though haha it says 1:8 which isnt that a ratio of magnification or something?
Dec 6 2011 6:50PM
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kalum.ko
Posts: 585 - Karma: 1,672
Or maybe f/8 I know all lenses have a one and then the aperature usally
Dec 6 2011 6:51PM
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Dub_Digital
Posts: 2793 - Karma: 634
yeah the only ones i found when i searched were all f8
Dec 6 2011 6:56PM
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[evan]
Posts: 5628 - Karma: 117
Sweet baby jesus what is that.
Dec 6 2011 6:56PM
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S.C
Posts: 3068 - Karma: 2,281
if you watch/photograph birds in bright sunlight and dont care about a shitty quality image, then go ahead and get it. if not, you probably have no use for a 600mm (which is 900+ on a crop, which I'll go ahead and assume you have) mirror (shitty quality) max aperture f8 lens
Dec 6 2011 7:26PM
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TWoods
Posts: 10014 - Karma: 8,386
Thats a mirror lens, they use mirrors to achieve longer ranges.

The aperture is shitty, often times they aren't sharp and suffer from a lot of issues with ghosting and haloing because they are using mirrors to bounce light around, rather than optical glass to change the light that enters the lens into the image that hits the sensor.

Also, a lot of those lenses will have vignetting, then a light ring, then the image will get darker again in the center. It's not always apparent, but it will be once you start doing any post.

They are the same design as a lot of consumer telescopes. I wouldn't spend your money on it!
Dec 6 2011 7:39PM
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EC-Skier
Posts: 3899 - Karma: 668
its f/8
zoom in on the photo it says 1:8
Dec 6 2011 8:07PM
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DrZoidberg
Posts: 5675 - Karma: 4,268
Yeah he's got it right. And I'd be willing to bet the guy above me is right too. An f1.8 mirror lens would be obscenely large. Look at how wide the opening is for f8 on todays mirror lenses, and that one too. NASA probably needed one for something cool in space but they couldn't pack/handle a real 800mm or whatever focal length it is.
Dec 6 2011 11:50PM
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