A fun way to see SR in action on a Pentax K10d

This is just a quick description of a cool way to see shake reduction in action in a Pentax K10d camera (test should work on any DSLR with stabilization, but it's really not necessary for cameras with lens-based stabilization because you can see it working through the viewfinder.) I think this is a useful test if, for whatever reason, you're suspicious the SR on your camera isn't working.

First I set my camera in manual mode, ISO100, and shutter time of 2 seconds. I used my 50-200mm lens at 200mm, but the test should work for any focal length. Then I go into a completely dark room with a heater light (or some other rapidly pulsing light source). I spend a few minutes and practice panning the camera so the heater light moves across most of the FOV of the camera during the 2s period. I was just standing up and panning my camera as steadily as I could.

Once I get my panning speed pretty good, I take a picture with the SR turned off. Here's how that picture looks (click on the image to see a larger version).



The heater light has traced out a path showing my own horizontal movement along with my random shakes and wobbles (which are considerable with a 200mm focal length)

Now repeat the same shot except with SR turned on.



Again, the light has traced out a path showing my horizontal panning, but the shakes and wobbles have been smoothed out. Pretty cool huh?

In this shot, you can also see on the left edge of the light path that it's brighter. This is apparently because the SR started out trying to attenuate the horizontal panning, but then gave up after the motion was too large. I found in more testing that it stops trying to prevent your panning motion starting at 1/5s and continuing to faster shutter speeds. This suggests the K10d SR is suitable not only for stationary subjects, but also for use when you are panning to follow a linearly moving subject (automobile, skiier, airplane, etc..)