Photo answers review
Photo answers rating 
The 18-270mm is not a new focal length for Tamron, as the brand produced one before that coveted the title of the world’s longest focal length range for SLR cameras. But this latest release introduces a newly developed AF motor called the Piezo ultrasonic motor (PZD) that delivers faster, quieter and precise autofocus. The vibration reduction (VC) technology has also been improved to enable the lens to be smaller than before (VC on Nikon and Canon mounts only). This helps the optic to be more compact, and even better for travelling.
Build and designThe lens appears to be well made, with 16 elements in 13 groups and seven diaphragm blades. It weighs just 450g and the barrel is just short of 100mm (96.4mm) when set to 18mm. The front of the lens takes a 62mm filter and comes supplied with a petal lens hood. The barrel features a nice wide rubber ring that rotates to extend and retract the zoom in one swift action. The barrel is a touch loose and will self extend if you hold the lens towards the ground, but it does have a locking switch. On the side of the lens sit two switches that control the VR on/off and focus on/off. VR is worth having as it makes a big difference at slower shutter speeds.
PerformanceWe tested this lens on a number of different subjects, including the portraits that are shown in the example images here. The handling is really intuitive and the improved focusing with the Piezo motor makes a really big difference compared to the previous model. It was snappy and worked with near-silent operation, so a pleasing experience in terms of physical performance.
Image quality wasn’t quite so impressive though, especially at the longer end of the zoom. The test chart results shown in our panel below speak for themselves, but in short the lens really struggles at wide apertures when using the higher focal lengths. At the wide-angle end the central area of the frame is nice and sharp across the aperture range, and it doesn’t degrade a great deal towards the edges either. As you increase the zoom, the performance remains good through to about 200mm, at which point the edge details start to soften, especially at wide apertures. This isn’t an uncommon situation with a lens that offers a vast focal length range, so didn’t come as a huge surprise. The distortion is obvious, with barrelling at 18mm and slight pin-cushioning at 270mm. It also produced excessive aberration shown as colour highlights along the edges of details.
PA VerdictThe test results in the lab are a little disappointing from this lens, but it’s still a good option for travelling light. The lens actually handles really well, and the VC stabilisation is very impressive. If you avoid the extreme end of the focal length and keep to smaller apertures, this lens delivers good images.
Key specMaximum aperture (wide) f/3.5
Maximum aperture (tele) f/6.3
Filter size 62mm
Autofocus motor Piezo PZD
Aperture blades Seven
Lens hood supplied Yes
Image stabiliser Yes (VC)
Minimum focus distance 49cm
Weight/size 450g/74.4x96.4mm