Hi Gordon and Tombomba,
Thank you for your feed-back. I really appreciate.
I looked closer at what happened,
- The K10D was on a tripod,
- The shake reduction was off,
- The remote was used with a 3 seconds delay.
So what went wrong?
On portrait mode
I was shooting on portrait mode, so the K10D was on vertical position, attached to the tripod through the socket.
The problem is between the tripod and the K10D. The tripod screw should be very tightly secured into the K10D, otherwise the K10D could rotate due to the heavy lens. For the DA* lens, remember that the gravity centre is no longer located on the K10D but on the lens! So if the head of the tripod is not screwed very firmly into the K10D, it may rotate.
On landscape mode
The same problem may occur in landscape shooting, this time not between the tripod head and the K10D, but at the tripod vertical control that should secured very tightly. Otherwise, the lens could plunge!
EDIT More on this
here with pictures!
More collateral damage
Page 62 of the K10D manual stipulates:
When using a telephoto lens, a tripod that is heavier than the total weight of the camera and the lens is recommended to avoid camera shake.
Since the K10D + 50-135mm averages 2 kg / 4.4 lb, does that mean that a 2 kg / 4.4 lb tripod is required?
As another collateral damage (the fisrt one was a bigger bag), a solid and 2 kg / 4.4 lb capable tripod is strongly recommended.