Image Stabilizer




For anyone who doesn't know, the Image Stabilizer is a nifty little feature in some lenses (including many of specific lenses that I own) refered to as "IS" for short. The basic concept is that, when it is turned on, it detects "camera shake" when you are taking hand-held shots... and with the magic of IS, it actually moves the lens element to compensate. The result is that you can get a clear image with a slower shutterspeed than you normally would be able to be hand. It has no use in tripod shooting, and isn't really helpful in good lighting conditions. However, when you find yourself shooting by hand in poor lighting, it can be very handy indeed.

A friend of mine was here the other night checking out my new Canon EF 70-200 f/2.8L IS USM lens, and got to asking me about how I liked the IS feature, and likewise turned it on as he waved the camera about looking throught the lens. I pointed out that the effect is really only seen in the final image... which later got me to thinking that I could easily put together a quick example for him. After taking a couple of shots and getting ready to send him an email pointing him to them, I figured I might as well go ahead and put them up here so that anyone else who happens by can see the examples as well.

Here you see two shots that I took in my bedroom with my Canon EOS-10D, with the 70-200 lens mentioned above, at 200mm (with the 1.6x multiplier of the EOS-10D, this makes it effectively 320mm equivalent for a film camera), f/2.8, 1/25th of a second. The image on the left is with IS turned on, the image on the right is with IS turned off...



To give you a bit clearer an idea, let's zoom in on the center a bit...



Note that the image without IS, is pretty much about what I would expect of myself taking a hand-held telephoto shot at 1/25th of a second. In other words, not something I would normally do... and while a tripod would result in a sharper image, IS still turns a mostly worthless shot into something that is at least worthwhile.

A few additional notes about IS...

- Don't leave it on when you don't need it. If nothing else, it will drain your battery - even when it isn't doing anything (Canon testing shows IS activated on a tripod mounted camera will drain the batteries approximately 20% faster, from what I have read).

- There are two different "modes" of IS. Mode 1 is a general use of IS, which is what I've used here. Mode 2 is specifically for motion tracking shots, like a moving car, where you are tracking the subject with intentional movement of the camera, as you take the shot. Mode 2 will "detect" the tracking movement, and disable the IS on that axis. In other words, it will continue to compensate as best it can for general camera shake, while avoiding a (futile) attempt at "correcting" the intentional tracking movement.

- Obviously something like IS drives the price on a lens up. If price is of major concern to you, and you don't do much hand-held photography, don't worry about getting a non-IS version of a lens you're looking at. On the flip side, if price isn't a major concern, I'd suggest getting an IS lens, even if you don't think you would use it too often. You will be glad you have it, when you need it. (Of course your mileage may vary... some folks I know simply REFUSE to shoot hand-held at all)

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