Hi guys sorry if this is a stupid question but I am a newbie to this and cant find any answers.I have a Sigma 50-500 lens on my E410 and it is set to autofocus for the simple reason that I have an interest in airshows and it is impossible for me to zoom,focus and pan at once.But when I click down halfway to autofocus while panning the lens goes from its current focus position all the way to the other end and back again which as you can imagine is hopeless and causes me to lose track of the planes.Is this normal or is there something I could do to rectify this.
Cheers Paul