is on my 100-400

[garymicheal]

should the is make a noise when turned on? and how do you know its working?many thanks guys for your answers

 

[ekimeno]

If it's anything like my 24-105, it should make a very faint whirring sound when your shutter button is halfway depressed. You should be able to test if its working by shooting something at 1/30 sec, and then again with the IS switched off. The shot with the IS engaged will be a lot sharper...

 

[turbotoes]

It does make a slight whirring noise, though mine is quiet compared to my 70-200 F4 (relatively speaking) The noise also continues for a time after you release the sutter button.

 

[seriousrikk]

It whill make a small click followed by a whirring (Sometimes the small click cannot be heard)

Absolute best way to check it is working. Zoom to 400mm and focus on something with IS turned off. Turn IS on then focus on the same subject. See the difference in camera movement between the IS off and the IS on.

 

[Geordi69]

It does make a slight whirring noise, though mine is quiet compared to my 70-200 F4 (relatively speaking) The noise also continues for a time after you release the sutter button.

It does this as standard, it says in the manual about it continuing for a few seconds after you release the shutter.