Web Analytics RiceHigh's Pentax Blog: K-7 Shake Reduction (SR) Problems

Monday, September 14, 2009

K-7 Shake Reduction (SR) Problems

The SR of this K-7 user is not working, but even worse, it causes blur! See the comparison photos he posts:-

http://www.pentaxforums.com/forums/pentax-dslr-discussion/73376-k-7-shake-reduction-problems.html

There was also another very similar report by another K-7 user previously. He then sent back both his K-7 body for replacement and also his Sigma lens for "updating", then he finally reported that there was no problem shortly after his brief test:-

http://www.pentaxforums.com/forums/pentax-dslr-discussion/68202-pentax-k-7-shake-reduction-problem.html

But it seems that the cause of the SR problem he encountered is not the Sigma lens, but just his first K-7 body, as he mentioned in the beginning that the same SR issue was found with his other Pentax lenses.

Possibly this user got a lemon K-7 of which the SR system just always caused blur.

But since I have never heard about similar SR issue reports for previous Pentax DSLR bodies with SR, this *new* K-7 quality issue really looks worrisome, especially when SR system causes blur instead of compensating for the hand-shake blur!(??!)

Least but not least, I think even the K-7 SR system does not malfunction, it is just not a great performer. Its effectiveness is low, especially for longer lenses, just see the results of this recent Image Stabilisation shootout test as carried out by the prestigious Japanese Impress DC Watch.

Comments (5)

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David Timmerman's avatar

David Timmerman · 808 weeks ago

I get a sneaky suspicion that the problem may be the use of a tripod. I know in my K10 user manual, they state you should not use SR on a tripod as the sensor movement will cause blur.

Oh great, the debate over in-camera versus in lens........PopPhoto did a study a couple years ago, and it showed that on smaller lenses, Sony and Pentax in camera tests equaled the Canon and Nikon models, but Canon's 70-200 IS lens outperformed the in-camera models.....The added qualifier though was the Canon IS lens was more than twice as much as the non-IS lens, which was more expensive than many of the third-party lenses....
K7 SR problem not reproduced after installation of the last firmware (v1.01....9).
http://www.pentaxforums.com/forums/pentax-dslr-di...
Real Engineer's avatar

Real Engineer · 808 weeks ago

Wow, a few people have issues that we're not even 100% sure what caused them and riceboy is claiming quality control issues across the entire line K7 production.
Ever thought it may really be a problem elsewhere or is it too easy to blame the manufacturer?
I got my firts K10D, it was damaged in transit so badly that the case cracked.
it still worked fine but I had it replaced.
Courier issue.
Big heavy box landed on my little camera.
I should have blamed Pentax.
Blogged about it to everyone as though Pentax had two horns and sat by Satan himself when producing products.
I now have a K7.
love it.
No problems.
So if I follow rice's example of extrapolating one incident into an problem with the entire production line and quality control, then I would have to make the claim that there are no one else with problems.
So there you have it.
Ricehigh's blog proves there are no problems with the K7 at all because I have none.
If it works in condemning Pentax for you, then it works for vindicating them for me.

r.e. SR testing:
BTW, what kind of engineer mistakes no controlled testing for controlled testing?
What controlled variable is there in that test?
The lens was at a different focal length, the two were never compared side by side.
Can they give me the vibration waveforms they induced into each camera?
No.
Because they do not have controlled testing.
Did they even try the simplest process of elimination, by placing both cameras on one platform so at least they were subjected to a near similar motion?
No.
So what we have is garbage in -> garbage out.
Much like this blog.
I saw the dcimpress study, the results were more interesting among the cameras rather than between them.

If anything it shows the SR built into the K-7 works (apparently better than the EP-1). The number of sharp shots more than doubled when the K-7's SR was turned on versus less than an 18% increase when the EP-1's IS was turned on

A more direct comparison between the two is difficult; it's complicated by the fact the EP-1 used a slightly higher shutter speed than the K-7. Different ergonomics and the ways the two cameras may be typically held may also explain why the EP-1 generally had a higher number of sharp shots.

Most surprising was that the number of sharp shots dropped on the EP-1 when the IS of the Panasonic lens was turned on, the number of sharp shots was LOWER than those with no IS at all. When both forms of IS were turned on they effectively cancelled each other out, that's not a surprise since a similar result is shown on a youtube video:

http://www.youtube.com/watch?v=KPdy52mR6Io

Which brings me another fairly surprising result: that the K-7's SR systems does not seem to interfere with the IS of the Sigma.

To infer anything further from the results would not be wise since it seems more of a casual experiment than a scientific test
Real Engineer's avatar

Real Engineer · 807 weeks ago

IIRC the Pentax recognises a lens that has IS and shuts its own SR off when it is such a lens connected.
That's not a very hard thing to do from an engineering perspective and makes perfect sense.
Till I find the source its only hearsay from me but the results support it.

The results sure do not support that it is ineffective as RH claims.

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