Canon EOS IS Bodies

[brucecyr]

Well, who knows, maybe camera companies will prove you to be right -- SFAIK the example you give is irrelevant.

 

What you need are a series of shots taken on a camera with BIS and a lens with LIS where the two systems can be forced to operate singly and concurrently but independently. Unfortunately that's not possible because no one makes such a system, so we'll just have to wait till one shows up. We can only hope we both live so long!

[fourfa]

There is no reason that dual IS is impossible. All I've ever seen here and elsewhere is "it seems like it would be difficult, therefore it's probably impossible." I don't buy it.

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In the early days of train travel, some people believed that the human head would explode (from very casual misunderstanding of dynamic vs static pressure) at speeds over 60 mph. Honestly!

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What I see in instrumented tests of lens-based IS (<a href="http://www.zen20934.zen.co.uk/photography/LensTests/IS_Tests/EF_24_105mm_f4L_IS/index.htm">here's</a> an example) is not that the image remains completely sharp down to some threshold shutter speed, below which is blur. What I see is a slow, mostly linear, decline in resolution as shutter speed lengthens. With single IS there's gap between the IS curve and the handheld curve, but both loosely follow the same curve.

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Imagine that vibration be characterized as slow, high-displacement, low-frequency movement coupled with quick, low-displacement, high-frequency movement. As I see it lens IS with its coupled glass elements has a pretty long travel relative to the image, but physical inertia that limits the response to high frequency movements. Sensor IS may have less travel relative to the image, but may have less coupled mass and potentially a better high-frequency response.

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Perhaps in the end these would make a very complimentary pair. Even if the combination didn't end up with more ultimate stops worth of shutter speed, if it could delay the loss of resolution even at 1 or 2 stops under the ideal shutter speed relative to single IS, it would be a big improvement.

[arnaud_lerecouvreux]

Bruce C has perfectly answered as for the simultaneous use of body and lens IS. I would like to add something to compare respective efficience of the two systems.I will speak only at a physical point of view.

 

The "move" of a picture is mainly depending of the rotation angle of the lens relatively to its longitudinal axis initial position.The detection of this rotation angle is made by the amplitude of the sensor movement. As the movement is due to the body which is hold in hands, normally the amplitude of the sensor displacement in greater in the lens than in the body.If the amplitude is greater, it is more easily detected, and consequently more efficiently compensated.

 

It is why, at my opinion, IS in the lens is more efficient than IS in the body.It is probably why Canon is not making an IS SLR body.

 

But IS in the body has the advantage to cost only once, if you have only one body, and to be efficient with every lens ...

 

Arnaud Lerecouvreux