Tech Question: How does the IS works?

[JulianoL]

I'm just wondering how does the image stabilization system works inside the lens? How does it "freeze" the image?

Thanks,

[Longwatcher]

If I remember correctly.
IS lenses have a small gyro in the lens (thus the spinning up time) which senses which way it has just been moved and how much and then adjust one or more optical elements to compensate for the movement. All of this happens in microseconds.

For a better answer see:
http://www.canon.com/camera-museum/tech/room/f_index.html

[JulianoL]

Longwatcher,

Thank you for the explanation.

[AzzKicker]

Have you ever used one? It doesnt freeze the image. It just tries to stabalize it. You still get slight movement but its a really big difference and helps get sharp photos.

[robertwgross]

Plus, IS doesn't do anything for a moving subject. All it does is to try to buck out some of the camera shake.

---Bob Gross---

[KennyG]

Did anyone read Phil's comments over on DPR about the 7D's CCD stabilization? The bottom line seems to be it is only useful for shorter lenses, which backs up my long-time argument that in-lens IS is best as it is tuned per lens.

[kb244]

Yea I read that review, Didnt surprise me too much. Though I wonder what kind of funky results would occur if you slaped on an image stabalized lens, with the sensor stabalizer on that 7D.

Far as image stabalization goes in the Canon IS lens. There are electronic sensors in the lens itself, causes an inner element in the glass to counter the direction that the gyroscope detects movement. Allow for sharp images upto 2 stops slower than normally capable.

Far as moving subjects it depends on which Canon IS lens you get, some of the higher end Canon 'L' Telephoto lens with IS on it, have two modes, one is the traditional mode, the other mode you turn on to keep the lens stabalized when panning. So for moving objects like a racecar for example, if you are panning with the racecar, IS-2 works rather well in keeping the movement stabalized while you are panning in one direction.