[stoppingdown]

Dave, thanks for pointing out to Dustin Abbott's review: I only had read a few preliminary findings by him.

 

So... too bad the 100-400 doesn't have and can't fit a tripod collar...  :unsure:

 

 

Second, I was intrigued by one of Dustin's test photos, with a butterfly. Either he has got larger butterflies than I have, or... Actually, I'm using the 150-600mm also for flowers, but only the larger ones, or resort to "environmental" portraits. In other words, the max. reproduction ratio of the 150-600mm is not high (1:5 according to the specs). So I checked the 100-400mm: it's 1:3.8. Better, actually. Also considering that the 100-400mm is sharp wide open, while the 150-600mm requires a bit of stopping down for max. sharpness, the new lens is better suited for flowers and larger critters with a smooth bokeh. 

 

In any case, being Sigma able to reproduce the IQ of a monster such as the Canon 100-400mm at one third of the price, I think it's a remarkable landmark for Sigma, also considering that it's the n-th excellent lens in the latest years. This definitely consecrates Sigma in the olympus of high rank lens manufacturers. Given that they also confirmed that they are working on more native E/FE mount lenses, I'm definitely happy.