I thought pentax does rotational SR as well?

kenyee · 07-24-2009, 05:15 PM

Canon claims they did it first

Canon develops Hybrid image stabilization system: Digital Photography Review

*pingflood* · 07-24-2009, 05:32 PM

This isn't rotational SR. It's angular -- when the camera is tilted forward/backward. And I do believe that is a first. Oddly, it doesn't seem they incorporate rotational SR in this setup. Looks like they are getting the terms a little confused.

edit: this is kind of interesting as it could conceivably lead to being able to tilt the sensor plane on demand...

edit2: DURRR it's optical not sensor shift.

Pål Jensen · 07-24-2009, 05:41 PM

Originally Posted by pingflood

This isn't rotational SR. It's angular -- when the camera is tilted forward/backward. And I do believe that is a first. Oddly, it doesn't seem they incorporate rotational SR in this setup. Looks like they are getting the terms a little confused....

Rotational SR is impossible in an optical system. You can rotate the lenses as much as you like. It makes no difference...

*pingflood* · 07-24-2009, 05:49 PM

Originally Posted by Pål Jensen

Rotational SR is impossible in an optical system. You can rotate the lenses as much as you like. It makes no difference...

Haha, you're right, for some reason I was thinking this was a sensor shifting system, didn't notice it said optical.

jogiba · 07-24-2009, 08:56 PM

Originally Posted by kenyee

Canon claims they did it first

Canon develops Hybrid image stabilization system: Digital Photography Review

"Canon Inc. announced today the development of Hybrid Image Stabilizer (IS), the world’s first* optical Image Stabilizer "

"* For use in interchangeable SLR camera lenses as of July 17, 2009. According to Canon research"

World's first for lenses, Pentax is for DSLR bodies.

Enhanced Shake Reduction. The Pentax K7's Shake Reduction unit adds several features over those of earlier models, including the ability to correct for rotational motion.

*falconeye* · 07-25-2009, 06:16 AM

Originally Posted by Pål Jensen

Rotational SR is impossible in an optical system. You can rotate the lenses as much as you like. It makes no difference...

Rotational as used here means rotation around the optical axis. Pentax first compensated for this in the K-7. Earlier claims (e.g., for K20D) have been due to miscommunication, according to Pentax.

Compensation for rotation of the optical axis in a purely optical system would require off-axis elements like a mirror or a prism. So, it is almost impossible in practical terms.

Normal shake reduction does compensate for rotation too, i.e., for rotation of the optical axis.

Besides compensation of rotational (or directional) shake (3 parameters), a camera does move, i.e., have translational (positional) shake (another 3 parameters). Canon seems to have introduced a correction of the latter, at least for some of its 3 parameters. Note that the camera would have to know the distance to subject for this to work.