Zoom Lens Decision? Don't know which to buy!

[rfortson]

Originally Posted by Thomas Campbell

The DX-sized sensor can only move a maximum of 5mm. When using longer than a 200mm lens, the compensation needs to be more than that.

Also, in-camera IS does not work if you are trying to do panning shots - you are supposed to turn it off, where the in-lens IS can help you with panning shots.

Still, it is very handy to have IS in all your wide-normal lenses for most shooters. Canon doesn't have IS in anything wider than the 24-105. But then again, some photographers are able to hand hold stuff very slow at wide angles.

Agreed on the lack of panning on IS. On the Olympus E-P1, it has a couple of different modes (I think for landscape only, portrait only, or both - if I recall correctly). I guess that's a way to try to accommodate panning. Not sure, though, as I don't usually use the various modes.

Where did you get the specific numbers for sensor movement for the APS-C sensor and 200mm focal length? While I understand that longer focal lengths require more movement, I don't understand why it has to be a fixed amount. That assumes a fixed amount of lens/camera movement. Just curious, as I haven't read that before.

Anyway, my experience with Pentax shake reduction has been pretty positive through three different models. I know it will accommodate a manually input FL of up to 800mm, so they at least try to stabilize to that length. Of course, that's pretty pointless as I can't hand-hold 800mm. :) I have occasionally hand-held my Bigma at 500mm, and it seems to work better than no stabilization. The 3000mm and 250mm also seem to work well from my experience. I do agree that a system specifically designed/manufactured for a lens should be better, but I think some stabilized lenses have slipped through that don't test as well as in-body stabilization. I think that's the exception rather than the rule, though.