> From: John Lovda <[EMAIL PROTECTED]> > > Someone provided a good explanation regarding this > many months ago which I can't find. Most camcorders > use CMOS sensors which I believe can operate with > "electronic" shutters; ie, the sensor itself turns on > and off to capture each image. The stablization > process is actually comparing the relative position of > the frame information to the frame before it. <p> John & Francis---
Professional video cams utilize optical image stabilization; and in fact Canon is a (or THE) leading supplier of pro video lenses, both IS and non-IS. That's where our EF IS capabilities came from. With regard to electronic image stabilization, they do it in video cams by comparing successive frames. The only way to get a comparable function in a still camera would be do subdivide the chosen exposure interval into small subintervals (perhaps powers of 2 to make the math quicker) with image realignment from each new subinterval onto the digital image 'accumulator.' For still imagery this may or may not be practical. I have no doubt that Canon and others have patents on it anyway <]B^). Note that there's one potentially big payoff of electronic over optical IS, if only they can get it to work: It'll stabilize the _subject_ motion and not just that of the _camera_. For that, I'd gladly sacrifice, say, a dozen pixels around the periphery. And of course, they would design the function to be switchable, allowing the use of all pixels in a non-stabilized mode. DGW * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
