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09-16-2010, 02:03 PM   #16
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QuoteOriginally posted by jeffshaddix Quote
Does anyone have more info on the SR introducing shake when there isn't any? I could see it introducing an imperceivable amount of blur, only noticeable compared to a non-sr shot. am I accurate or could it be worse than im thinking?
Jeff, I did a large study on this subject in February when I accurately measured the image blur introduced by hand shake.
Here is a link to the study on Scribd

The graph below shows the most important results.

The top line shows motion blur (in pixels) with the handheld camera with SR turned OFF. Here you can see motion blur slowly increasing at shutter speed of 1/125 sec to 1/30 sec. At slower shutter speeds motion blur increases quickly.

The bottom line shows motion blur with the handheld camera and SR turned ON Here we see motion blur is well controlled down to a shutter speed of 1/8 sec. Bear in mind that a motion blur of 0.5 pixel is a good result.

The interesting thing though, is that the variability in the results increased to 1 pixel motion blur from a shutter speed of 1/15 sec and slower. See the second graph. When the variability increases this indicates that handholding technique is coming into play. The really interesting thing about this study was my finding that I had to rest after every five photos, otherwise the image blur increased quickly. Presumably muscle fatigue was increasing physiological tremor.






09-16-2010, 02:24 PM   #17
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The possibility of operater error is always there, but I know for certain that the SR function on my K20D has failed upon occasion. Swith is on, but icon says off. Turn it off and back on, and it works. Sometimes goes off after a few shots, without changing the switch. Never has remained on when I turn it off, however. I've learned to check it often and the problem seems to be happening more frequently.
Reguardless, most shots with your specs should have been sharp, if your hand-holding technique is any good at all.
09-16-2010, 09:36 PM   #18
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To add confusion to the issue, there is also this article about shutter induced blur: LumoLabs -- Shutter-induced blur for Pentax K-7.

I never hit this problem, but on the other hand, I don't shoot wide-angle at 1/25 either.
09-17-2010, 02:54 AM   #19
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QuoteOriginally posted by Laurentiu Cristofor Quote
To add confusion to the issue, there is also this article about shutter induced blur: LumoLabs -- Shutter-induced blur for Pentax K-7.

I never hit this problem, but on the other hand, I don't shoot wide-angle at 1/25 either.
The problem is at speeds of 1/80-1/125: and look at the graphs above... is that 'Lumo-blur' that causes the little peak in blur around 1/80 shutter speed? Why would there be more blur at 1/80 than 1/40, with the SR turned on? Very strange.

09-20-2010, 03:27 AM   #20
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QuoteOriginally posted by jeffshaddix Quote
All,
I just recently got back from a shoot where the majority of my pictures had noticeable motion blur. About 75% of the pictures taken were at 18mm at 1/25 with SR on. Out of those shots, I'd say 2/3rds were significantly blurry (motion blur not focus blur). I'm fairly confident I waited for the SR icon in the viewfinder before shooting each shot. I'm also confident I wasn't THAT shaky!

Odd thing is I hadn't noticed the issue before on other shoots, and I can't reproduce it anymore. I'm thinking it may have been a software glitch (I have the latest 1.10 firmware) and I just needed to turn it off then on.
DSLRs seem to make photographers less careful because of the assurance of SR but I would say yours could have been a software glitch rather than camera shake.

In my case (Samsung GX20), the issue is a little different but with the same unhappy result. The SR occasionally does not turn on with the half-press on the shutter button even though the SR switch is set to "On". Sometimes SR stops functioning while taking pictures. This can be verified in the metadata where the SR hand icon is shown crossed out. My complaint on the subject is at GX20/K20D Shake Reduction OIS Erratic Operation
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