Can someone explain "Optical Image Stabilizer "

[ltilley]

What does that mean and what does it do?? THANKS!

[Stephen Lutz]

There are two ways to stabilize an image. One: (Used by Canon and Nikon). In the lens itself, place tiny gyroscopes and micromotors that shift one lens group to compensate for the tiny shake that occurs when hand holding a camera. This results in an extra 3 stops or so of handholdablity before blur occurs. Basically, you have to buy a lens with this IS feature. It is most useful for long telephotos where camera shake is more pronounced in an image. I have a 300 f/4 IS which I can handhold down to about 1/60 of a second. Pretty cool!

Two: (used by Minolta) Stabilization is provided by manipulating the sensor itself rather than an element in the lens. Thus, the sensor shifts ever so slightly with movement to compensate. The main advantage to this system is that every lens has the benefit of IS, so you don't have to buy special lenses.

Both systems work very well, but remember they won't do anything for subject movement. So, if you shoot at 1/20 of a second, and the subject is moving, you will still get blur. IS is most helpful when the you are in low light and the subject is still. However, for any lens over 200mm I think IS is pretty much essential for sharp pictures and a steady subject in the viewfinder.

[ltilley]

Wow! Thank you for the answer!!!!

[another view]

Great explaination above. I don't own any of Nikon's VR lenses but have used them and they're very impressive. When I get ready to replace my 80-200, I'll definately get their 70-200 VR lens (almost happened last night when I came pretty close to dropping it on concrete!).

Just realize that it's a tool to add to your arsenal. VR doesn't help in every situation but if you do low light hand-held shooting it will be a great thing to have. Most of the time I'd personally choose faster lenses over VR but 200 at f2.8 is already pretty fast (little DOF because of this) and having a lens you can hand-hold at 1/30 or better is really nice.

Just like hand-holding without VR, some people can get away with slower shutter speeds than others. With practice, you should be able to lower the minimum speed you can hand-hold a certain focal length at. And like Stephen says, you'll gain about another 2-3 stops over not having it.