Sony Digital Camera Forums

At a guess if it is not the same as the 70-200 then (ie forward normal and back limitied to over 3m) then it is a focus and lock, free limiter like the canon ie focus on subject then turn on and you can then limit the range focused to to however many degrees of rotation around the point where you turned it on, a bit like an electronic version of the HSG version? Only wild guess though.

tim

Occasionally the AF will hunt and this takes time with some long lenses or macros that have a fine step in their focus control.  You use the limiter to keep the focus range limited to near the range you are working to avoid long travels to infinity (focus!) and back.

For example if you're using a long FL to focus on a nearby object, if the AF doesn't get a phase lock, it will continue running the focus to infinity and then all the way back until it sees lock.  Can be long and frustrating.  Use the locks to constrain the range.

I usually manual focus so it is not much of an issue.  I have the range limiter on a couple lenses.

Gazraa I think the focus limiter on the 300 F2.8 works the same as the one on my 600 F4.  What you do is undo the little screw, make sure the arrow on the small threaded ring lines up with the mark on the lens barrell and focus on an object at the distance you want to limit the focus to.  Now if you turn the small threaded ring on the lens anti-clockwise, as you look from the camera, as far as it will go and then tighten the screw the camera will now focus between the distance you set and the nearest that the camera will focus (I think that's the right way).  If you turn the threaded ring clockwise as far as it will go the lens will focus between the distance you set and infinity.