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A 500mm mirror lens on a digital camera

Posted: Thu May 18, 2017 8:11 pm
by melek
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I can't recall how I came to be in possession of this lens. I don't recall buying it, and I think that maybe it came with something else that I bought.

I guess "Clear View" is the brand, although I've never heard of it. It's a T-mount, which means that it can be adapted to whatever lens mount you can find. Currently, I have a 42mm screw mount adapter, which is easy to adapt to digital.

Back in the day, these were called "cats," which stood for catadioptric and is a design for a telescope. With a telescope, the eyepiece is mounted to the rear of the lens.

The aperture has full and half stops from f/8 to f/16. There are no visible aperture blades so I'm not really sure how it does this. Maybe the aperture simply is part of the rear of the lens and cannot be seen.

Filters can be mounted in back of the rear element.

Like other long focal length lenses, it can focus past infinity to allow for barrel expansion.

It's a sharp lens, but handholding can be a real challenge.

Here are a couple of photos. If you’ve not shot a mirror lens, its major characteristic is the donut-shaped out-of-focus regions.

These were shot with a Sony A7 II.

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This is two horses, although it looks like one.
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This was shot with a 50mm lens so you can get an idea of the difference in the field of view.
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The donut-shaped out-of-focus areas are clearly visible.
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Re: A 500mm mirror lens on a digital camera

Posted: Thu May 18, 2017 8:23 pm
by Julio1fer
I also have a no-name (well, Vivitar) 500 mm mirror lens in T-mount, but it has no aperture ring. In fact I cannot remember any mirror lens with aperture, although I may be mistaken.

If you did these hand-held, it is an achievement! I found it hard to keep the frame steady, let alone focus sharply.

It is interesting to point these lenses at bright point reflections, such as sun on rippled water surfaces. Nice abstracts. Someone also recommended me to try bright, colored neon lights out of focus, but I never got to it.

Re: A 500mm mirror lens on a digital camera

Posted: Thu May 18, 2017 8:25 pm
by PFMcFarland
Good shots hand-held there, Mike. Of course, putting this on a digital camera with in-body stabilization, hand-held should be no big deal. My preference would be to also use a monopod, for the same reason Julio states. I really need to get my two cats out sometime, especially since I plan to sell one of them.

PF

Re: A 500mm mirror lens on a digital camera

Posted: Fri May 19, 2017 8:51 pm
by Philip
Lovely pictures with good detail and texture.

I have a Tokina "cat" lens (300 mm for M4/3) and it is mostly pretty disappointing, never especially sharp or contrasty. Yours seems like a better deal!

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Re: A 500mm mirror lens on a digital camera

Posted: Fri May 19, 2017 11:13 pm
by melek
I have to confess that I rarely use it. I just don't have much need for a 500mm lens.

I bought the Sony A7 II last year. Love the camera. I don't plan on stepping up to the A9. A bit too pricey for my wallet.

Re: A 500mm mirror lens on a digital camera

Posted: Sat May 20, 2017 2:07 am
by Martolod
i have one of those beasties....great little lens ... :thumbup:
i still use the Sony A7....fwiw......it is everything i ever wanted in a camera digital or otherwise.i can stick all my lenses on it.
the only lens i do not have is actually a Sony lens...but i am not missing it.
those 500mm catadioptric lenses are at times a good bargain. :lol: :clap:






to be honest, if it were not for the price tag , the Sony A7 series and beyond, but in particular the the A7 is the ideal stepping stone to go from film to digital as a beginner in digital. I have always regarded camera bodies as simply just that a body...with a few convenient features like metering and occasionally auto focus, and a way of storing the captured image.the most important part for me has always been the lens and the scene.i try not to get to hung up on the bells and whistles available of the body.it's kinda like admiring the buttons and dials on a stove but forgetting about the pot and the food cooking in it
just my 5cents worth.

Re: A 500mm mirror lens on a digital camera

Posted: Sat May 20, 2017 11:39 pm
by melek
Julio, I always thought that the "cats" didn't have an aperture, but I didn't really think about it until I read your post.

I had a 250mm Sonnar for the Contarex, and I tried to handhold that once, but the lens was so large and heavy that it really was impossible to use without a tripod.

Regarding the Sony A7 II, I think this is a sweet camera. I'd like to see fewer buttons on it. Quite frankly, I sometimes forget which button to press to get to the white balance setting or to magnify the image.

Love the camera. Would love it even more with fewer buttons, switches and dials. :)