Yesterday I had another chance to test my a6000 with the Sigma 150-600mm C + MC-11.
It was totally unexpected - and unfortunately it took me a bit unprepared. I was just at the beginning of the southern climb of the Col d'Allos, France, interested in Fall colours, when, during a bend, I seemed to see a bird, far away, that definitely looked like a griffon. I was just wondering - hey, I should really mount the 150-600mm just in case - and in a few seconds, two bends later, dozens of griffon were flying, also at low altitude, over my head, together with dozens of crows. The road, in that place, is very narrow and two cars can't comfortably cross, so I had first to find the first reasonable place to park. Then, not knowing how long the birds could have stayed, I first started shooting with the SEL70200G that was already mounted on the a6000. It made sense, first because of some "overview" shots, and also because a couple of vultures were so low that they did a good job of filling the frame also at 200mm. When I saw that they weren't in a hurry I mounted the 150-600mm.
I shot about 250 frames with the 150-600mm. I'll take the whole weekend to sort them out, but at the moment, despite a number of very good compositions, none seems to be tack sharp, even though some are decently sharp. Even though the background was pretty clear - the blue sky - the camera was probably fooled, in some cases, by the high number of birds around. I also did some mistakes, that is I switched from f/11, which is my preset for birds in flight - to f/8, thinking that it was enough. But in some cases there are two or three large birds in the frame, and only one is in focus because the others are out of the focusing field. The camera didn't pick the one that made more sense composition-wise, because of course it's not smart.
But this is not part of my question. There is also a number of frames shot with the 70-200mm and I expected better results from it, first because it's faster in focusing, second because I can perfectly hand hold it. Actually, some shots seems to be spot on for the focus... but are blurred, in the sense that I see a ghost image. I just realised that it should be an effect of stabilisation and that was my fault: I kept "mode 1", while in theory "mode 2" should have improved things, being optimised for panning.
But - as far as I understand, "mode 2" just doesn't compensate for horizontal motion. In many cases I was vertically panning, because the bird was flying at me. I'm just guessing whether with this kind of subjects - vultures glide with a very predictable flight - I shouldn't be turning OSS completely off, and next time be smarter and cool enough to set up the tripod...
More details as I keep on pruning and observing which settings made for the best shots.