Canon IS effectiveness

I had a 28-135IS which I sold to purchase a 17-85IS (For the extra width) and I've been very pleased with both of them. The IS works about 2 stops worth in my opinion, sometimes more and it's well worth having. For Xmas, my wife and daughters bought me a Panasonic FZ5, which I intend will live in my car to replace the Ixus 40 I keep there and also as an introduction to serious photography for my 15 year old daughter. (Sorry all you Canon diehards, but it's much better value and image quality than the S2IS!)

Since I started using it on Xmas day, I've been staggered by the image quality and the effectiveness of the IS. (It's not as good as the 350D and I won't be getting rid of that, so please don't have a go at me) My initial opinion is that the IS is far more effective than that on my Canon lenses - up to 4 stops or more - 2 stops better. I find this a little dissapointing when related to the Canon. My 17-85IS averages £425 or so in the UK for the lens alone, the FZ5 cost £240 including a body.

Has anyone else noticed this phenomena or compared Canon IS with other makes? Is it just the physics of the lens size? I know that compact superzoom lenses are much easier and cheaper to produce than DSLR ones because they are so much smaller. I'm intrigued and would be interested to see the comments and observations of everryone else on this erstwhile forum

I'm on my 3rd Panny FZ IS series P&S and they're hard to beat as an all round package. I had a FZ5 and they are really very nice indeed. They can be a bit deficient on ISO but they are a P&S after all and every camera has compromises. I just ordered a FZ20 to play with. Being replaced by the FZ30 but still well up there. 12x Leica zoom, IS and 2.8. Hmmm ... no brainer

The Minolta DSLR's have body based IS too. Seems to be an effective way of doing things. Suddenly all your lenses have IS!! They have some excellent packages right now.

Allbelow are purely speculative, and in order from my guess of most likely to least likely.

1) Smaller lens -> lighter lens elements -> faster, more effective IS

2) The active lens group can be closer to center of gravity and thus the center of rotation : easier to correct.

3) The FZ is wider than your 17-85, so the sensors for shake and wobble can be further from center of gravity: more sensitive

As for the minolta; they have a great AS technology. IF I understand it correctly, should correct 3 degrees of freedom, as opposed to Canon's and Pentax's 2 d.o.f.

I understand the first 2 points of the reply, and I thank you for them, but I don't understand the 3rd. How is the FZ5 wider than a Canon 17-85? Do you mean that the sensors in the FZ5 are within the body and therefore spaced more widely apart than they can be in the 17-85 lens?

yes, exactly. Since they are farther away from the center of gravity, they should be able to be more sensitive, as they must travel farther for any given shake.

Although, I have no idea whether the FZ designers took advantange of that, or even if their vibration gyros are of the kind that would benefit from an increased lever length.