Northern Ireland Aviation Enthusiast's Forum
General => General Discussion => Photography => Topic started by: smudge on August 05, 2013, 09:05:24 AM
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Kudos for Nikon on their work on balancing the mirror in the D7000. Makes the 5D2 look awful ( and I say that as a life-long Canon user ).
Moment of Shutter Release: 5D2, 7D, D700, D7000
http://www.youtube.com/watch?v=sLZqUJZ9ruw (http://www.youtube.com/watch?v=sLZqUJZ9ruw)
Look at that mirror bouncing on the up and down strokes.
Edit: it could just be a sloppy tired copy of the 5D2, but given that Canon headlined 'mirror bounce reduction' in the 5D3 I doubt it!
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And here's the original trusty 5D
Canon 5D Shutter in Slow Motion
http://www.youtube.com/watch?v=2juLVywOa2M (http://www.youtube.com/watch?v=2juLVywOa2M)
boing boing
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... and an interesting interview with Canon engineers about how they try to maintain autofocusing despite the mirror 'bucking'
http://www.canon.com/technology/interview/eos/eos_p2.html (http://www.canon.com/technology/interview/eos/eos_p2.html)
( Do try to ignore the marketing superlatives elsewhere on the page )
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This cutaway diagram is of the 5D shows clearly the small autofocus mirror behind the semi-opaque main mirror. Towards the bottom of the camera is a spectacle-type lens which focuses parts of the main image onto the AF sensor.
(http://occurs.lineum.org.uk/public/misc/photography/.5D_cutaway_af_labelled_s.jpg) (http://occurs.lineum.org.uk/public/misc/photography/5D_cutaway_af_labelled.jpeg)
( credit to canon.com for the original image from which this was cropped )
So you can imagine how a flapping main mirror causes the AF system all sorts of issues; it can't reliably detect out-of-phase conditions whilst the mirror is in motion and this has a direct effect on the burst rate. For this reason many cameras have options to allow shutter to override AF in burst mode, or vice versa.
Looking forward to a good mirrorless camera in the near future!