Originally posted by rajubhai55 Sony also has it. Same can be said of in lens stabilization
There are things which in lens stabilisation can do as well as in body (sensor shoft) stabilisation bet there are things it cannot do as good or even at all.
In lens stabilization:
- can most definitely
not correct for tilted horizons.
- can be used to simulate a shift lens (Composition Adjustment). -
but is only an approximation and will introduce some distortions
- can most definitely
not be used to reduce or eliminate star trails for astrophotography (Astrotracer).
- can even be used to simulate the effect of an anti-aliasing filter -
but will be a poor implementation applying a different level of filering over different parts of the sensor
the above is valid for any in lens stabilization - it is due to the principle of how it works rather than any specific implementation.
The easiest disadvantage to undersatand is the inabiliaty to do the horizon correction and astrotracer functions. In lens stabilisation works by moving a lens baout halfway through the optical path. This can shift the image left/right and up/down (and in most cases also any diagonal combination of that) but what it cannot ever do is rotate the image. Horizon correction is entirely about rotating the image so cannot be done. The astrotracer function requires shifting of the image (combination of up/down left/right) which in lens stabilisation can do but also image rotation - which in lens stabilisation can never do.
The issues of in lens stabilisation related to using it for moire reduction and composition adjustment are less obvious but are due to the different optical geometry of the two systems. This difference however make in lens stabilisation better in one particular area - in wide angle shots it is more accurate than sensor shift over the entire sensor area. Sensor shift would require the sensor to move a different distance to correct for shake at the perimeter of the picture from what it needs at the centre whereas lens shift more closely approximates the correct shift over the entire picture area. The effect is more evident the wider the filed of view (shorter focal length) but is typically negligible above 50mm or so.
The converse applies for moire reduction. At long focal lengths lens shift can work almost as good as sensor shift but at shorter focal lengths it would make a mess of it. WIth sensor shift moire reduction performance is independent of the focal length.