[bymy141]

Without wanting to start a fight, I think it's a good one After all the Pentax engineers know how their SR works.

No, let's not start a fight. I'm not intending to fight, that is not in my nature.
It is just that I cannot follow the wishdom of the Pentax engineer who wrote the manual.

Also, Falk Lumo is not the only person who has put a K-7 SR to the test.
There has been some testing done on the SR effects of the K-7 and that investigation proofs my point.

Please read the following article:
Study of the Effectiveness of Shake Reduction in the Pentax K7

Out of which comes the following chart:


As you can see, both with MLU (Mirror Lock Up) and without MLU, a K-7 mounted on a bench suffers of no negative effects of SR "on" versus "off".
The fact that the Pentax manual states different does not mean that it is true.

As what P Smith writes in his article:
"Here we see that the base or static blur is 1.11 pixel. This increases by 0.21 pixel to 1.32
pixel if the mirror is not locked up but the camera is still rigidly mounted, eliminating
camera vibration. From this we can conclude that there is a motion blur of 0.21 pixel in the
sensor caused by mirror slap. This is the same whether SR is On or Off because with no
movement in the body SR will send no corrective signals to the sensor."

I'd not bother to turn off SR when mounting on a tripod, with no physical SR switch to easily turn it on/off the effects are so minimal that it is very hard to meassure its impact, let anlone see the difference.

- Bert