i've had a sigma 24-70mm f2.8 for just under a year now, and i've been having issues with the zoom ring being stiff eg when i'm zoomed in i need to press against the lens head for the zoom to go out.
because of this its having difficulties in focusing.
has anyone had any experience with these lens? and how i can solve this? i purchased this from CR Kennedy, so will it make sense to get them have a look at it?