has your IS ever gone out?

[JWPhoto]

My IS is going out in my 24-105, it only seems to make a difference in longer exposures so I have not been using it on a tripod (in reading, canon added "tripod detection" back in 2000 so you should be able to leave it on). Does anyone have any sugestions or more details on the "tripod detection" before I send the lens back to canon (my 70-200 2.8L IS does not have this issue).

15+ seconds with no IS


15+ seconds with IS

[JWPhoto]

I called Canon today and they said that not all IS lens have the "tripod detection" and I should just turn the IS off when the lens is on a tripod. If you are wondering what “tripod detection” is, it is where the lens detects that it is on a tripod and turns the IS off automatically.

[Inflex]

Interesting. Wasn't aware of this.

“The IS mechanism operates by correcting shake. When there is no shake, or when the level of shake is below the threshold of the system’s detection capability, use of the IS feature may actually *add* unwanted blur to the photograph, therefore you should shut it off in this situation. Remember that the IS lens group is normally locked into place. When the IS function is active, the IS lens group is unlocked so it can be moved by the electromagnetic coil surrounding the elements. When there’s not enough motion for the IS system to detect, the result can sometimes be a sort of electronic ‘feedback loop,’ somewhat analogous to the ringing noise of an audio feedback loop we’re all familiar with. As a result, the IS lens group might move while the lens is on a tripod, unless the IS function is switched off and the IS lens group is locked into place.”

Image Stabilization on Tripods

[jezterr]

you should actually turn off your IS when it's on a tripod, as IS is traditionally used to compensate for handshake. so when it's on a tripod, the older IS systems tend to overcompensate for the minimal shakes that you get from wind/vibrations and actually makes things worse.