Tamron usually make excellent lenses, but the Tamron 24-70mm doesn’t appear to be one of them. Of course it may be that I have just been unlucky and bought a below average sample.
Although fit and finish are very plasticky and lightweight, the lens seems well made, with a reasonably smooth zooming action and positive click stops on the aperture ring. However, results have been less satisfactory, especially at 24mm. Results at the wide end of the zoom are very soft at full aperture and it’s about f8 before there’s any sort of crispness to the image. From 28-70 performance is much better, and if that was the full range I’d be reasonably happy with the lens’s performance.
However, the problem is that there are plenty of OK 28-70 zooms, so buying a 24-70 and then discovering you can’t really use it at 24mm is a real problem. To be fair, these tests were carried out using a Fuji S2 Pro, and in some other tests, particularly with the Sigma 20mm f1.8, I’ve found a marked difference between the same lens’s performance with that camera and with Nikon digital SLR camera bodies, so perhaps that was the case here. Unfortunately I made these tests some time ago and no longer have the lens available to test with a Nikon body. Based purely on the tests I’ve made then, I can’t recommend this lens for digital SLR cameras.