1. It works better in lenses than on bodies
2. One less thing to be fixed in a camera. If it is in the lens
and goes bad you send the lens in and keep shooting. If it is in
the camera and goes bad you send the camera in and quit shooting
--
When you see a beautiful collection of photons, capture them. You
will never see them again.
Let me start off with saying that there is no inherent conflict between in-body, and in-lens IS. If you had access to a lens where in-lens IS would work well, say a 500mm tele, you could always simply turn off the in-body IS.
- 1
Says Canon. Small surprise. Really, there seems to be little difference in the effectiveness of the respective approaches. There is a case to be made for in-lens IS for very long teles, however that only means that if you had a 500mm tele with in-lens IS, you would shut off the in-body version. For shorter focal length, I've yet to see that there are any significant differences. In fact, I'd say that moving the sensor should ultimately be more effective. At this point in time, effectiveness would seem to depend more on the implementation than principle.
- 2
For the additional cost of a single IS lens from Canon, you could buy one to several EOS 400 backup bodies. #2 is a strange argument, particularly since in this digital age, bodies are more likely to be replaced than lenses.
I'd add the benefits of having a stabilized finder image from in-lens IS, and the fact that your lens image circle goes from being a negligeable issue to being a complete non-issue.
Of course I could alse counter with arguments pro in-body IS.
- 1
Works for all lenses, (adding huge value to large aperture lenses in particular as there are no in-lens IS alternatives available
at all ).
- 2
Is inexpensive - Pentax charges a $100 premium for their K100D over its non-IS sibling, but that is still taking advantage of customer demand. But even so, $100 to gain IS on all your lenses is a deal I believe just about any Canon/Nikon/Olympus owner would happily buy into.
- 3
In-lens IS depends on having a mobile lens group in the optical path, which inherently is disadvantageous in terms of optical performance even assuming that there are no problems with tolerances and wear (which of course there is). Even if disabled, the lens group and its associated surfaces stay in the optical path. From an optical point of view, getting rid of the mobile lensgroup is a benefit.
- 4
In-body IS can be codesigned to help with anti-dust features.
My personal feeling is that in-body IS should be built into all digital SLRs, regardless of make. It was not possible during the film era, but it would seem a no-brainer today. Just do it.
For a company like Olympus that is always going to be at a disadvantage in terms of pixel density for a given sensor resolution, I'd say having in-body IS is almost mandatory, particularly given their large line-up of high-quality non-IS glass.
