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Forum: Lens Clubs
03-20-2015, 08:56 AM
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Forum: Lens Clubs
11-14-2013, 02:17 AM
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300mm is about the longest I'm comfortable with shooting handheld. This 300/f5.6 exists as Super Paragon, Ohnar etc. and is quite small and realy light. It does need a deep hood though, which adds to the physical length. For some reason catch-in-focus does not work with this lens on either a K-7 or K-5ii so a good focusing screen is essential. f5.6 is a bit optimistic, in reality it is probably nearer to f6.3. It crops up all the time on eBay - there is even an Ohnar version with a front diaphragm which lets you 'stop it down' in a strange way.
Super Paragon 300mm f5.6 Mirror Lens by kh1234567890, on Flickr
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Forum: Lens Clubs
11-13-2013, 05:55 PM
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Forum: Lens Clubs
10-07-2012, 01:25 PM
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Forum: Lens Clubs
04-11-2012, 03:04 PM
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In practice shake reduction gives you anything up to about two stops leeway over this - the above boating shot was taken at 1/90 sec. It was just a personal observation.
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Forum: Lens Clubs
04-10-2012, 04:15 PM
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Unless you have a steady hand and a sharp eye be prepared for some disappointment if you get a 500mm/f8. In my experience 300mm is about the limit for shooting handheld. Don't spend too much on it. Get a good deep lens hood, mirrors are prone to flare which will kill your contrast. Be careful with your shot angles or learn to live with doughnut bokeh. There is little wrong with T-mount, especially as you can't change the aperture anyway. Watch out for temperature changes, mirrors are much more sensitive to this. Be amazed by the size and lightness of cats.
Sometimes things do work out though :)
Boating by kh1234567890, on Flickr - Super Paragon 300mm f5.6 |
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Forum: Lens Clubs
03-18-2012, 10:50 AM
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Forum: Lens Clubs
11-14-2011, 12:48 AM
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Hmm. Pretty much as I'd found. The rear filter seems to make little difference to sharpness or contrast. The test also shows that 500mm cats are a real pain to focus manually. That's why I gave up on 500mm and got a cheap 300mm cat instead. With that I get reasonable shots even handheld.
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Forum: Lens Clubs
11-07-2011, 09:16 AM
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Perhaps someone could resolve this one once and for all - by actual test or by raytracing. In my limited experience the plain flat rear 'UV' filter makes no difference whatever on either a Tamron 500/8 or a Super Paragon 300/5.6.
It's been a long time since I did physics in anger, but all the filter will do is to increase the optical path by its thickness x (refractive index -1), easily taken up by the normal infinity focus over-run. Any distortion (astigmatism) correction by the filter is likely to be pretty minimal because of the long focal length of a typical cat lens and the thinness of the filter glass.
I'm willing to be proven wrong though.
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Forum: Lens Clubs
11-04-2011, 05:20 PM
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You will find that not having any rear filter will not make any difference - this Internet myth started with a line in a badly translated Nikkor 500/8 instruction leaflet. All that not having a filter will do is to slightly shift the infinity focus point, but since cats normally focus well beyond infinity this is not a real problem.
As for the difference in performance - watch out for temperature changes with cats. The mirror can distort temporarily if you take it from warm to cold or vice versa. Just wait until it equilibrates.
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Forum: Lens Clubs
09-09-2011, 09:35 AM
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Forum: Lens Clubs
09-07-2011, 04:48 PM
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There are many photo examples taken with various mirror lenses on this long running thread (original in French) Google Translate. There are some pretty crap cat lenses about. The old Tamrons seem the best by far.
A panorama with my cheap Super Paragon 300mm f5.6 :
Barbie in the Park by kh1234567890, on Flickr
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Forum: Lens Clubs
05-27-2011, 01:22 PM
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Forum: Lens Clubs
05-19-2011, 03:48 PM
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