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11-09-2013, 01:32 PM   #1
Chris 259
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Mirror Lens

I have a 500mm mirror lens which I have just received. My K-30 says it is in focus but when I review the photo it clearly is not. I am led to believe a mirror lens will give a superior photograph. I ave set the focal length and tried combinations of settinge but still get the same result. It has also been tried on a K-m and has the same result. My question is why does the camera state it is in focus but the final result is very prro, so poor that the zoom lens I use is far better.
Or is it a fulty lens?

11-09-2013, 01:41 PM   #2
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QuoteOriginally posted by Chris 259 Quote
I have a 500mm mirror lens which I have just received. My K-30 says it is in focus but when I review the photo it clearly is not. I am led to believe a mirror lens will give a superior photograph. I ave set the focal length and tried combinations of settinge but still get the same result. It has also been tried on a K-m and has the same result. My question is why does the camera state it is in focus but the final result is very prro, so poor that the zoom lens I use is far better.
Or is it a fulty lens?
You should register and post some samples. That's the only way to tell for sure!

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11-09-2013, 01:44 PM   #3
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Sample pictures with EXIF would help, does anything appear to be in focus?
11-09-2013, 02:58 PM   #4
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Are you sure the focus is just wrong, or is it shake blur, thin DoF, is the lens just really bad? Please search the forum for more threads about mirror lenses, I remember some time ago a person complaining that their mirror lens is really bad, and then others tried giving him hints how to improve IQ (basically, add hood, use tripod, use timer, shoot raw and post-process the photo). At that focal length, any shake will make the photo look unclear. A lens hood can also really improve the IQ of a mirror lens, some people just roll a piece of paper around it to make a tunnel

11-09-2013, 03:11 PM   #5
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Well, most mirror lenses will not give a superior photograph, so you've been misled.
11-09-2013, 03:28 PM   #6
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QuoteOriginally posted by First Poster Quote
I am led to believe a mirror lens will give a superior photograph.
Would love to know who told you that

A mirror lens CAN deliver decent images if handled correctly. As noted above, you will a fast shutter speed, use a tripod, use a hood, use a remote or the timer and you will also need very good light and very good focusing control. The depth of focus on that lens is extremely small, about 3 inches @ 25 feet and about 11 inches @ 50 feet.
11-10-2013, 03:28 AM   #7
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QuoteOriginally posted by Chris 259 Quote
I have a 500mm mirror lens which I have just received. ... Or is it a fulty lens?
Bonjour,

Can you tell us what exactly your mirror lens is ... and post us some sample images? Thanks, J
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