The Tamron 18-270mm f/3.5-6.3 Di-II VC PZD offers an eye-watering focal range that translates to a huge 15x optical zoom
Ergonomically, the signs are very good. The zoom ring fills slightly more than the middle third of the lens barrel and has a textured rubber feel that provides a positive grip surface. Rotation is backwards when compared to Canon’s own 18-200mm but matches the rotation direction used on Nikon’s equivalent lens. The extent and feel of the 90 degree throw are both just right.
The focus ring, which rotates in AF mode, is at the very front of the lens and at the rear are two sliders to change the focusing mode and to switch Vibration Compensation (VC) system on and off. The AF system is not especially quick but it proved very reliable during field testing.
Similarly, the VC system holds a very steady view but then jumps if the camera is moved by more than the electro-mechanics can accommodate: different users may either appreciate the first fact or lament the second!
With such a wide zoom range on offer can the Tamron maintain image quality right across the full spectrum of focal lengths? The good news is that chromatic aberration is insignificant at wideangle and normal settings but this is not the case at longer focal lengths.
MTF testing revealed a mixed bag of sharpness results, with the maximum focal length the weakest in terms of both sharpness and colour fringing. Tests conducted on other Tamron superzooms in the past suggest that the results from this review sample may be below par but the longest focal length weakness has always been present.
Overall it seems that Tamron has been just a bit too ambitious in this lens. This is unfortunate given that its 270mm setting is a key selling point but there will doubtless be times when owners will be grateful for the extended zoom range that, to some extent, does trump other more modest zooms.