Not really test passed

Now for the lens. I tested the lens on D3 / D700 in less than optimal lighting conditions (forest clearings, from 18.00 clock). If you want to make good wildlife / nature photography you're most from dawn or in the evening on the way and there is relatively little light. Compared I VRII the lens with my 70-200.

Long story short: for my purpose is the lens not suitable.

Better to almost identical results (depending on focal length) achieved with a 70-200 + TC14E / TC20E and / or "cropping". With my current equipment I have 400mm (only in conjunction with TC20E). Therefore me the area was 400-500mm very important. Unfortunately, exactly this focal length range of unschärfsten with the images. Even strong stopping down to F11 has not really helped here. For me, then only a 200-400 or 500 VR is still in question. Since I will have to save some.

Under the following conditions, this lens is definitely worth a recommendation:
1. no urgent need for optimum sharpness of the image (from F8 below 300mm good Schräfeleistungen, about weaker, 500 well)
2. mostly Vergößerungen to 13x18 required 20x30 only selectively, depending on the template or only Fig. Internet max. HD size.
3. rarely Ausschnittsvergößerungen (from 400mm to lack of sharpness are excerpts wg. More problematic if focus is very important)
4. When using DX-format and under good light conditions that make no further cutouts necessary because you can perfectly define the clipping with the wide range of focal lengths for each motif.
5. cameras with low-noise sensors in high ISO range, (z. B. D3 / D700).

For amateur photographers (and the holiday / travel photography wg weight)
with a budget highly recommended. z. B. Who in the Zoo want to photograph in good weather, will be able to achieve good results with this lens there. With this lens perform Wildlife Photography I do not think though impossible, but is only possible with restrictions. What good is the image stabilization in low light and long exposure time when the animal is moving? Always remember 1/500 are almost at moving animals. If a flying bird to be photographed, then I'd ever mind. Set 1/1000 or 1/1500. Then the aperture to 6.3 or even 8 and you're quickly in high-ISO performance.

For Spotter
the lens is sufficient in any case. The focal length range is optimal. For large passenger aircraft, or landing fighter jets should still be able to achieve good results. In launching fighter jets I would necessarily choose to 1/2000. The panel probably at F8 (the better for sharpness) and then we again need a lot of light or high ISO.

Very impressed I was by the image stabilizer. The did a great service, as long as the subject is not moving. :-)

Addendum:
for weight. I was surprised. It felt lighter than my 70-200 and was the same length as the new Nikon 70-200, which however does not also change when Zoomem in length when retracted. Wearing the Sigma was very pleasant. However, I am also different weights used (3kg and more).