The latest news, he's ditching Pentax to complain about Canon. We
should only be so lucky.
Thibouille wrote:
AFAIK most of his so called tests and stories have been based on
bodies he may have handled but not even own (in most cases).
Draw your own conclusions...
On Sun, Jul 19, 2009 at 6:00 AM, P. J. Alling<[email protected]> wrote:
Just don't read Ricewhine's measurbator blog on the K7's autofocus tracking.
It will either shake your confidence or infuriate you. I found it by
accident, and wish I hadn't clicked on the link. Not because I much care
what he thinks, but I don't want to up his Google rating. He's another
blogger who does more harm than good, much like Kenny Boy, though I believe
he actually tests, if you can call it that, the equipment he savages.
paul stenquist wrote:
Good to know. It's what I suspected based on use, but it's nice to know
that my suspicions aren't just wishful thinking. Thanks for taking the time
to test.
Paul
On Jul 18, 2009, at 7:09 AM, AlunFoto wrote:
Better quantified this time.
Yesterday I took stance on a bridge above a highway, and photographed
large trucks coming towards me. The speed limit at this place is 100
km/h, and on top of a gentle slope. I shot series of each truck, and
have tallied the percentage of out-of-focus shots from each series.
The cameras were set to:
- SR on for shots with DA*300, shot freehand
- SR off for shots with FA*600, shot from tripod
- AF-C, multipoint
- ISO 800
- Av-mode (aperture set to f/8)
- DNG file format.
Focus was judged by 100% view in Adobe Bridge CS4 without rawfile
conversion. I took a conservative attitude, judging anything that
wasn't perfectly sharp on the car front as mis-focused. I typically
looked at details in the grille (hope it's the right word?) or the
number plate.
Between each series I allowed the camera to save all files before
commencing a new series, to make sure camera speed was not held back
by a full buffer.
K20D + DA*300/4: 13% mis-focused, averaged over 9 series
K-7 + DA*300/4: 7% mis-focused, averaged over 7 series
K20D + FA*600/4: 43% mis-focused, averaged over 7 series
K-7 + FA*600/4: 25% mis-focused, averaged over 11 series
Each series held between 10 and 19 shots.
Both lenses are focus-calibrated with the K20D, but not with the K-7.
I therefore suspect that the K-7 results could be somewhat improved.
There are bound to be many unchecked sources of random variation here.
One is whether the trucks had cargo or not. If empty, they bounce a
lot more and could introduce motion blur. I suspect the 600mm shots to
be affected by this. With the small number of series, I can't rule out
that the two cameras have got an uneven share of empty trucks. However
I did the same experiment, at the same place, five days ago with the
K20D only, and the results from yesterday seems consistent with my
previous results.
So all in all, the real-life numbers pretty much mirrors the nominal
doubling of the frame rate. Not the subjective feeling that the K-7 is
_more_ than twice as fast. Not in this situation anyway. However this
test, tracking approaching objects, is very different from panning a
bird flying from one side to the other.
Jostein
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The free man owns himself. He can damage himself with either eating or
drinking; he can ruin himself with gambling. If he does he is certainly a damn
fool, and he might possibly be a damned soul; but if he may not, he is not a
free man any more than a dog.
--G. K. Chesterton
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