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07-01-2012, 07:45 AM   #1
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Shake Reduction Study

Hi all.. I was curious about the SR operation in my k-5 and i took some test shots that revealed some strange results..

1) SR operation regarding the Shutter speed.

I took some shots with my DA*55 on and opened the raws with Photome. At the manufacturer notes i noticed that all the shots with speeds: 1/10, 1/25, 1/50 ,1/200, 1/800 where stabilised. Is this normal?
i mean i find it normal to be stabilized at speeds below 1/50 but should shots at 1/200 and 1/800 be stabilized too?

2) SR operation regarding Focal length.

I saw difference at the Focal length of the shot and the SR focal length.Here are the results

DA*55
Focal length SR Focal length
55 63

DA18-135
Focal length SR Focal length
18 19
24 24
36 36
48 45
68 62
100 81
135 100

Al the numbers came from photome. So is this operation normal or i should be worried?
Thanks in advance.


Last edited by Dionisis_K; 07-01-2012 at 07:52 AM.
07-01-2012, 10:43 AM   #2
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1) SR operation regarding the Shutter speed. yes - with SR turned on, it will just keep stabilizing until you 1) turn it off, or 2) put it on a tripod with the 2 second mirror delay, where upon it will disable SR automagically.

2) SR operation regarding Focal length. yes - On this it is going to be difficult to tell. Did you set the focal length based on the markings on the lens or via the readout within the viewfinder? PhotoMe is just reporting what was recorded in the EXIF metadata, and I really do not know how accurate the physical marking on the lens is with respect to the viewfinder/EXIF focal length recordings.

07-01-2012, 10:58 AM   #3
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QuoteOriginally posted by interested_observer Quote
1) SR operation regarding the Shutter speed. yes - with SR turned on, it will just keep stabilizing until you 1) turn it off, or 2) put it on a tripod with the 2 second mirror delay, where upon it will disable SR automagically.

2) SR operation regarding Focal length. yes - On this it is going to be difficult to tell. Did you set the focal length based on the markings on the lens or via the readout within the viewfinder? PhotoMe is just reporting what was recorded in the EXIF metadata, and I really do not know how accurate the physical marking on the lens is with respect to the viewfinder/EXIF focal length recordings.

i understand that the readings from the ring might not be as accurate thats why all the data i provide is from the exif. And i find it weird that the camera has read 55mm but the SR read 63mm for example.
07-01-2012, 02:45 PM   #4
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An image to show what i mean..

Attached Images
 
07-01-2012, 02:59 PM   #5
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Well normal or not I do see these differences aswell sometimes.
07-01-2012, 03:54 PM   #6
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I just checked a few images from a few lenses with interesting results. All images were taken with a K-7.

  • Manual lenses (manual entry of FL) seem to have the same recorded focal length in the Camera Section and the Manufacturer notes under SR.
  • SMC-F 24-50 and SMC-F 35-105 always record the same FL on both places.
  • SMC-F 35-70 records a slightly shorter FL (~2mm) in the SR section.
  • DAL 55-300 at the 300mm end is all over the place. The FL was 300 in the camera section (and I remember the lens was at its long end) and the SR section had 284, 268, 292
  • DA 35 F2.4 recorded 35 in camera and 36 in SR
  • DA 18-55 all over the place: 18 (19) 30(36) 55(53)
07-01-2012, 04:09 PM   #7
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The "manufacturer" exif data was all reverse-engineered, as far as I know, so the exact meaning/significance of that field isn't really known...
07-01-2012, 04:22 PM   #8
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Regarding the SR focal length, it takes about 2 seconds for the SR system to synchronize its anti-shake action to the image movement of the camera. It could be that there is a feedback loop in the SR program such that it optimizes the anti-shake by adjusting the FL value used. So that if SR FL at 63 resulted in less camera movement than the FL 65, the camera would use the modified value. In other words, the "SR FL" is just a value that the camera inserts into some formula to make the system work better, no big deal to worry about.

Regarding whether SR is used by the camera or not, if SR is turned on, its always trying to synchronize with the camera movement. However, if you shoot before the 2 sec. required to synchronize, then the camera is just reporting that it was not used.

Frankly, i think a lot of the OOF shots reported for the K5 are the failure of photographers to wait to see the SR hand come up in the VF. 2 sec is a long time when one's attention is focused on the action in front of the camera. IMO, its far better to rely on shutter speed and and not SR if snap shooting. Just turn SR off unless one is doing slow deliberate shooting, e.g. macro shots.

07-02-2012, 08:27 AM   #9
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Thanks all for your answers.. So since it doesnt bother me or my shots i 'll let it be...
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