Now that some test-shots have been made, the winner is...:
The Sigma 10-20mm
It is the sharpest near and far (absolutely important)
It is the widest (second most important)
It has only little distortion
(ok, don't bother too much)
The colors are clear (if a little too blue)
It has a pouch (not a decisive factor)
It is not a FF-lens (well, if you don't have money for a FF-body this is irrelevant)
It produces some nasty contra-light artefacts
(so make sure you read the detail review with hints and tipps on how to
avoid those artefacts)
It has a cr*ppy lens cap (not a decisive factor)
The Sigma 12-24mm
is certainly the straightest (tested) and lowest vignetting (not tested), but it has the worst color-fringing
of all tested lenses and tends to come out brown-red in high-contrast situations. It is sharp in the middle and at the edges but in the end not as contrasty as the Sigma 10-20mm. For people having or planning for a FF-body this could be the killer-wide-angle-zoom as it is wider than the all the other 14mm+ wide-angle lenses/zooms for FF-bodies! On a FF-body its fov is equivalent to a 8-16mm (!) on a APS-C-body. It has the most pronounced problems with contra-light leading to ugly red-brown stripes
under a lot of conditions, but otherwise has a very colorful reproduction
The Tokina 12-24mm
was not the worst lens: It did fine with contra light, not giving the dreadful brown-red stripes of the Sigmas and it was quite sharp (clearly better in the lower left corner than the upper right one). But it had the most obvious difference in lateral vs tangential sharpness
in the corners. And it suffered from blown-out highlights (twigs of trees against the sky). And it is the brightest lens (f4) at all lengths in this test.
The Tamron 11-18mm
is not too bad in the centre but deteriorates quite pronouncedly at the borders/corners plus has some heavy color-fringing at the borders
. In that respect it is the worst of all tested lenses! With respect to flare and ghosting it is better controlled than the Sigmas.
B.t.w.: I also tested the Nikon VR 18-200mm
in this group. Here's how it performed comparatively:
At 18mm almost as sharp as the Sigma 10-20mm, but the borders show color fringing and the contrast is a little less than the winner. These findings hold true for wide open as well as as for f8. This is a truely astonishing feat as the Nikon is f3.5 wide open vs 5.3 for the Sigma 10-20mm.
With regard to macro-power (:P) the results are as follows:
=20.3cm/2.36cm=8.6:1 @ 0.30m
=15.8cm/2.36cm=6.7:1 @ 0.28m
=16.4cm/2.36cm=6.9:1 @ 0.24m
=18.9cm/2.36cm=8.0:1 @ 0.25m
So the clear winner here are both Sigmas. But only if you don't count the Nikon 10.5mm fisheye...
Read more in the upcoming detail-reviews with strange things like "White-Dwarfs
", etc. ...
P.S.: And don't forget: Your copy of this lens could be cr*p (as examplified in my review of a former copy here
) so make sure you get a good one...