IS on BIF

[Rich S]

There is a pan mode on my 300mm f/4L IS( mode 2). When I am shooting at +1/1000 sec. Is there an advantage to using IS or does it hinder AF ?. What is it used for if the IS is no use over that speed? I have always turned on Mode 2 and someone told me it makes the AF not work as well and doesn't stabilize at high speeds anyway. I want to find the answer? Anyone have have it??? Thanks .... Rich

[rdricks]

I'm not sure about hindering AF, but I know I turn IS off for BIF. I feel like I am always "fighting" the lens. I get a lot more keepers with IS off.

[ibdb]

IS should have no effect on AF. There could be some delay in the IS spinning up to speed if you don't start with focus activated (either with a focus button or half-press of the shutter). That shouldn't slow AF, just IS.

I usually leave IS on, but not because it's going to make a difference at 1/1000. I leave it on because most of the time I'm looking through the lens at a long focal length, leaving IS on makes it easier for me to see the scene. If the scene is moving around without the IS, after a while, it bothers my eyes.

A side note -- lighting has been so poor for me almost every time I've gone looking for birds lately, so getting 1/1000 is only a dream. I've been shooting at 1/400th or slower, at ISO 1600 and even 3200. That makes IS even more valuable to me.

[gasrocks]

IS mode 2 does indeed help with BIF.