AdamJ said:
This guy has some good examples using the 120-300mm + Sigma 1.4x combo.
http://www.capture-the-moment.co.uk/tp/reports/sigma-120-300mm-f28-os
I've previously seen another blog with images of seabirds (puffins, I think) using the same combo but I can't find it now.
Thank you Adam, those are fabulous pictures! I wonder if he has sold many prints of them?
Again, this confirms my belief that the yet-to-be-released "art" version of the Sigma 120-300 f/2.8, could very well be a world beater. Time will tell.
Btw, here are some fantastically sharp shots done with a D4, via the 120-400 Sigma lens I'm considering purchasing. (He also has others done with a D700 that look about as good).
http://www.pbase.com/jeff1959/nikon_d4_images_july_2012
Check out the full size "original" versions. Of course those cameras' pixels are huge compared to my crop camera...but the sharpness of the float plane pictures looks fully professional to me. They could almost be used in some kind of ad campaign. Makes me wonder if he used much AFMA, if any...because the focus he got is always "tack sharp" regardless of the focal length he used. Of course most were shot at f/8, which no doubt helped a bit.
I kind of hate that I still envy pretty much all pictures I have ever seen, regardless of lens, shot with a D700. Yes, the 12MP pixel dimensions of the image are a lot smaller than a 5D2 or 3, but the ultimate resolution of details, surely isn't that far behind, if at all (especially at higher ISO). But...it's Nikon... !!
The reviews of the Sigma lens say the color is "warmer" than the Canon 100-400.
But that is exactly what I want. The Darwin Wiggett review, and images like the above, are what has convinced me to try the lens. The photozone.de review, looks like the lens is positively horrible. Based on the above pics, it looks like they got a bad sample, and Jeff got a perfect sample.
Some of the other shots on pbase, done with an older Canon Rebel and the Sigma 120-400, look unimpressive, obviously the lack of AFMA is a big factor, as well as the wimpy AF of those cameras in the first place. The bokeh, especially background bokeh, looked kind of bad on those as well...but that is something I need to try for myself, to see if I can live with it. Background bokeh with a long telephoto, even a Canon L, isn't always the smoothest anyway. Even the 200L I tried, had background bokeh that did some unusual things...of course if the background is pushed enough out of focus, then it looked very smooth and pleasing...so those anomalies don't show up.