[camera_nut]

ls it a good idea to turn it off when not needed so the battery will last longer? Or does it not make much difference?

[biz-engineer]

ls it a good idea to turn it off when not needed so the battery will last longer? Or does it not make much difference?

Yes and no.


The sensor is floating on a plate with no defined position when the camera is switched off (SR coils aren't powered), that's why if you shake (not too vigorously) a Pentax K1 or K3 or K5 you can hear something moving inside the camera, that moving thing is the floating sensor.


- In live view mode, SR coils are continuously running whether SR is user enabled or not, because coils are powered to bring and keep the sensor at the center of lens optical axis, when SR is enabled coils are powered to compensate for camera motion instead of only keeping the sensor aligned with lens axis.

- In SLR mode, every time shutter button is half pressed, or AF button pressed, the AE metering module and AF module and SR module are switched on (even if the camera user disabled SR). AE and AF modules stay active for as long as you have set it in camera (default is 10s, there is also 1s, 3s, 30s and Off AE and AF modules are never powered off), while SR module only stays active for 3 seconds (if no exposure is done) regardless of what the AE metering timer setting is. If an exposure is done, SR is switched off immediately after the exposure without waiting for 3 seconds.

SR on Pentaxes is one of the reasons (I suppose) why Pentaxes have lower battery capacity than the Canon or Nikon DSLR that don't have their sensors stabilized, so the CIPA figures are higher when shot with non IS lenses.

So to answer your question, the best way to save power is not keeping Live View mode running for too long since SR is working as long as LV is active. Optimal use of LV would consist of setting up as many camera parameters as possible with LV Off, then switch on LV, take your photo and switch off LV mode, SR coils powered down immediately when LV is switched off, camera goes to standby mode. When using the camera in SLR mode, half pressing the shutter button or back AF button keep the SR coils active, so in order to same power do compose first and only after you are satisfied with composition throught the viewfinder then half press shutter for focusing and taking the shot, doing so SR is only draining battery power for a very short amount of time (can be much less than 3 seconds if you are quick).