Back Goes the sigma for exchange.

[DarkShadow]

I am having problems with the OS on the 150-600C where no matter what position OS switch is mode 1 or 2 I am all over the place at 600mm looking though the viewfinder its seriously jerky.Backed off to 400 or less its better but still jerky and having a hard time keeping focus point..Shutting off the OS off is only a subtle difference from being on.I used to hand hold 150-500 on a canon mount at 500mm @ 1/250 of second and get a sharp image and a stable viewfinder. I called Sigma and the tech support dude said no thats not right and something is wrong.So I got my RMA paid return from B&H for an exchange.

Kinda of a bummer and inconvenient but this is the first return I ever had to do from anything from B&H.Maybe the UPS driver knocked the snot out of it or just a bad copy it does happen.Making sure I get a dock if everything is ok with the second copy and change the firmware to dynamic OS