Advantages and disadvantages of all lenses and none is absolutely perfect. My priorities were in (1) the maximum possible image detail (what else an ultra-wide-angle?) (2) Focus (3) lowest possible distortion, (4) contrast and colors (5) resistance to glare. The last point is often underestimated - by the strongly curved lens of an ultra wide-angle "collect" such an objective often scattered light from all possible directions, whereby the image of color, contrast and sharpness lose.
The Tokina 12-24 mm 2 are missing, which can be almost one third scene at such an extreme wide-angle lenses. In addition, I found the picture quality not convinced (distortion and sharpness).
The Sigma is in image detail, sharpness and contrast even more convincing (the old model while still better than the 3.5-edition). For this, the equally attractive price .. Here Sigma distorted the images already comes relatively visible at 10mm. Of course, this however could correct later. The scattered light sensitivity is satisfactory. However, Sigma is unfortunately known for a certain series dispersion, so that the objective quality may be a matter of luck.
The Tokina 11-16 convinces with extreme sharpness even in the picture edges and excellent color and contrast. The distortions are in convincing framework. Unfortunately, however, the Tokina is missing due to the small zoom range of 11-16 mm some flexibility in image composition, the Tokina is most likely a fixed focal length. However, the biggest drawback of the Tokina is its extreme sensitivity to bright light sources. Bright sunshine in image contrast and color can ruin the entire image. That should not be underestimated if one has before (like me), mostly landscapes, and to photograph architecture in general outdoors. Eternal careful to the correct position of the sun limits in the picture composition considerably. In addition, you have at 11 mm focal length almost inevitably at some point the sun directly in the image.
Here finally scores the Canon wholeheartedly. The scattered light insensitivity of 10-22 is not only practical and exceeds many L models, it also allows for a number of photos that would not be possible with other lenses. Stunning photos in the sun are directly possible with perfect contrast and color! The sharpness of the Canon is also superior to the Sigma. Only the edges of the image are a weak point here. with large aperture they are clearly out of focus, but stopping down to at least f / 7.1 can the remedy. A further advantage is the very low air distortion at 10mm. Not only arise so perfect architectural images. Even daring spontaneous freehand series images can be so zusammenrechnen still a perfect panorama without the usual interfering distortions from a variety of programs! Color and contrast of the Canon are also simply the best of all 4 lenses (incl. The otherwise superior in sharpness Tokina 11-16). Then there is the largest zoom range from 10mm to full flexible 22 mm.
This was the decision clear to me: Canon still offers the best overall package for compelling images and flexible composition in any situation.
