Tamron's professional-level 24-70mm f/2.8 lens costs about the same as its brand-name equivalents, so is it worth the price? Tim Coleman puts it to the test. Read the Tamron SP 24-70mm f/2.8 Di VC USD review
Image stabilisation is deemed surplus by many in a lens like this, but I find it useful for low-light work as it increases the versatility of this high-quality, general-purpose optic. Build quality is good, although I would like to see a couple of tweaks to the handling, such as a wider focus ring.
Image sharpness virtually matches the Canon equivalent optic, and the Tamron model is capable of some impressive results. It is not without the usual distortions at wider focal lengths, however, and at f/2.8 watch out for certain out-of-focus areas.
The Tamron SP 24-70mm f/2.8 Di VC USD is not cheap, but with its sharp results, good build quality and image stabilisation, it is good value.