Wow, that's strange. Maybe it wasn't working properly or it was the 1st generation IS. From what I heard the first ones only worked, but pretty much only under ideal conditions. If it was a bit too dark, the IS would not be able to correct the camera shake. Nowdays the reviews say that the IS is much more forgiving and corrects down to I think 2 or 3 fstops. I'd be curious to find out if that is really the case from somone that has one of the newer IS lenses

I haven't had any problems with IS. All the photos taken with it, even one handed, have come out fine.

I've kinda stayed out of this discussion as I'm Nikon, but IS/VR is awsum in my opinion. If yours isn't working, I'd get it checked out. The technology isn't magic and you still can't hand-hold a 2 second time exposure, but when you need a bit of help or you've just jogged up a hill for the once-in-a-lifetime shot, it works.

Marty, just one minor correction, IS/VR doesn't depend on amount of light. It depends (or reads) contrast (which, I suppose, could translate to amount of light) and attempts to offset rapid movement. The "first gen" IS/VR worked in one direction. The second gen worked both up and down and left and right. Both Canon and Nikon have a switch to change between "active" and "passive" (or whatever Canon's label is.) This means that if you are in a moving vehicle chasing a gazelle over an African savanah :biggrin: , then you'd want the active setting. If you are just trying to adjust for heavy chest heave, due to running after a subject, the "passive" setting would be correct (it is mostly uni-directional.) Neither works well from a tripod, however. A monopod is fine, but steady bench-rest is generally a no-IS?VR setting.

My guess is that the IS/VR mechanism depends on which lens/manufacturer under discussion. My Canon 500mm clearly whirls up to speed, leading me to suspect that a gyro is being used to steady some lens elements. I also find that IS does help, even on a tripod (contrary to the manufacturer's instructions).
Weng

which zoom 70-200 or 70-300
 

would the 70-200 IS 2.8 give a better enlarged image to equal the max 70-300 IS 4.6 image? I know there is a huge $ difference, but what about the image quality?
thanks,
Canonmick

Can't speak to the Canon lens, but I suspect the same principle is true about most of the major manufacturers - you get what you pay for. The 70-300 is aimed at amateurs, primarily. It is lighter weight, plastic parts, not as strong a "build". The 70-200 adds other features. I think Canon's has VR as well as internal focus motor for quick focusing. As to enlargement, that is mostly a function of how steady the camera/lens is held and how carefully the focus is done (sharpness.) I would think upsizing can be done from the 70-200 that would produce a final product to rival the 70-300, easily. I regularly produce 50+ meg files from mine (Nikon) that will produce a sharp image up to 12"x16" at 300dpi. You can, of course crop out the center to imitate the 300mm. Hope this helps. My money is on the 70-200, but then I do this for a partial income :biggrin:

I have owned both lenses and highly prefer the 70-200 2.8. The photos are much crisper and cleaner. It also allows for better shooting in lower light conditions. I mainly use the 70-200 for shooting horses and athletes. It allows me to shoot in indoor facilities without a flash. I currently use a 100 2.8 macro for shooting my orchids, now if I could just get myself a lightbox set up, I'd be all set!

I think I posted a picture of my setup. I use Home Depot reflectors like for incandescent shop lights and Full Spectrum curled Compact Florescents as light source. Works just fine. I shoot exclusivly in RAW mode, so I can rebalance the white balance if it's off a bit. The reflectors come with a spring clamp which I removed and fastened to standard lighting poles. They are the left-most two lights in this setup http://www.orchidboard.com/community...s/DSC_3105.jpg The tall one on the right is a studio light retrofitted to hold 3 CF bulbs.

thanks to Ross and Laura for the opinion. Now all I need to do is sell the one month old 70-300 IS lens and an older non-IS lens before I can buy the 70-200 2.8 lens.
Canonmick