Question on Canon 70-200 f/4 IS lens....

[fxxrodriguez]

I've never used this lens and I'm planning on renting it for an upcoming long trip; I noticed that it has 2 separate focusing switches.. 1,2 and 3-infinity. Can someone briefly explain how these switches are used? Or maybe you can direct me where I can find this explanation? I've done a search here and unable to find any info on this issue.
Thanks much

[CaptainNH]

Basically, it's a switch that changes your minimum focus distance from 1.2m to 3m.

It used to speed up the AF when your subject is 3m or more away, meaning that the lens doesn't have to hunt all the way from 1.2m. In terms of the internal focussing mechanisms, there's as much movement involved in moving from 1.2m to 3m as there is from 3m to infinity, so even though 1.2 to 3m doesn't seem like much of a change, it's significant for the USM that's driving your focus.

[fxxrodriguez]

Captain NH... disregard my reply... I was confusing the lower switch (Mode 1,2) with the focusing switches I mentioned. Which leads me to ask... what's the Mode 1 & 2 switch used for?

Thanks again...

[CaptainNH]

The Mode 1 and 2 switch relates to the Image Stabilisation.

Mode 1 stabilises in two directions.
Mode 2 is used when panning - it detects which way you are moving the camera, and stabilises the opposite plane.

The most important IS mode to remember about is the off switch - which you use when mounting on a tripod.

[fxxrodriguez]

Great... thanks again for your help...looking forward in using the lens for 2 weeks soon.