Originally posted by Snappertim Yes OK its hard to see what size a object is when you can only see it against other objects the size of which you also do not know, but even if its not the same lens its DNA looks similar, on the larger lens the zoom lock switch is a clear clue as to its origins, the smaller is a rebadged Tokina 70-200 f4 for sure, and the reason for the larger lens is Full Frame the 60-250 is only APSC, and the future is full frame, Sony has just stated it intends to have 20 full frame lens on the market in a few years, maybe the have come to the conclusion if you want to be number one you have to do what the guy at number one is doing Nikon!!
I think it's very likely a fullframe lens, but what makes you so certain it's an f/4 lens? Just look at the diameter in relation to the lens mount. This is a fat lens! Fatter than the 50-135/2.8, which in turn has about the same diameter as a Canon or Nikon 70-200/4 (as you would expect).
Also, it has a tripod collar, which suggests it's heavier than the 50-135.