Allan Mee wrote:
> The term ''IS' has been mentioned a lot lately with regard to lenses - but
> I've been too afraid to ask lol The only 'IS' I know of was a range of Oly
> fixed zoom lens film cameras that looked liked SLRs - e.g. the IS100, IS500,
> IS1000 etc.
> I suspect the term 'IS' has nothing to do with said cameras (as it was used
> in connection with Canon Zoom lenses IIRC)
>
In this context, IS means Image Stabilization, which is Canon's term and
has become the generic reference term as well. Nikon calls their version
VR, Vibration Reduction, I think, and other manufacturers have other
names. My favorite may be "Mega OIS", Mega Optical Image Stabilization.
There are two very different ways of implementation. The original IS and
VR, and some others, are accomplished in the lens, where one part of the
optical system is moved based on signals from motion sensors to keep the
image on the film/sensor stable. The other broad category uses movement
of the sensor to accomplish the same thing, more or less.
The new Pentax K10D is unique in being able to rotate the sensor as well
as move it up and down. It will be interesting to see how well that works.
Different implementations, as expected, have different effectiveness.
The best lens based ones seem to add 3+ stops to handholdablility. Body
based ones seem generally to be a little behind that so far. But they
have the advantage of working for whatever lens is mounted. There is a
lot of variation. One test of the new Leica for the Panny version of the
E-330 showed no more than about 2 stops of effectiveness, which
disappointed the tester.
The interchangeable lens IS and VR lenses from C and N are already into
second and third generation designs and are very good, but generally
larger and heavier than the non stabilized versions.
It drives Oly fans wild that there are no IS solutions in their DSLRs
except for the one new Leica.
Moose
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