Tamron and Sigma are currently wielding arms in the latest optical battle at the standard zoom length of F2.8 24-70.
Dustin Abbot has done the full review of the Sigma and is currently testing the Tamron G2, resolution wise the Tamron seems to be the sharper at all but 50mm.
The G2 is thought to have the same optics, it may have the same optical configuration, but it has been upgraded and for the most part of the range it outperforms the G1 sibling.
Here are the two compared with additional compared lenses......the second part is to come:
https://www.youtube.com/watch?v=efRzdYkgbn4
The second part dealing with vignetting/bokeh/rendering gives the edge to the Tamron, but here, there is not a lot between them, except the G2 suffers from less vignetting.
https://www.youtube.com/watch?v=cQw5-T5TnDk
These tests show the optical formular betwwen the first version and the G2 are clearly not the same, some new polishing improvements seem to be reducing the onion ring bokeh which was an issue with the first version.
As far as I am seeing the new standard zoom at least in Canon land is 24-105fL IS by far more people are busing it
These are bright constant F2.8 zooms and not to be confused with a walkaround transtandard variable aperture zoom, they are part of the F2.8 series of the three "Holy Trinity" zooms as they are so often refered to.
Careful, dave. The f/4 zooms are neither one nor the other. 16-35, 24-120, 70-200 are all f/4 and optically decent, plus lighter in weight.
Ok, that's true as a popular lens the F4 24-105mm FL IS, is a good all rounder, but the 24-70 F2.8 remains the staple diet of pros who need the extra light and a shallower depth of field.
However, a rice pudding and cucumber comparison!
I don't know.
I think, if you only want to get narrow DoF, you can get away with the longest FL 105 and f/4 which should bring a similar DoF if I step a bit backwards. But for sure, the 24-70 are more pro and got better weather seals than the extending 24-105 / 24-120.
I'm not really a client for either lens, nonetheless, the shape up between Sigma and Tamron in all departments merit's some interest given it's these things which have driven an upward trend in affordable semi- extreme lenses as well as pro zooms.......
.....and I do like F2.8 lenses.....but then..hey!