It’s the lightest and most compact telephoto zoom in its class, but is it a must-have for Sony E-mount users? Michael Topham put it to the test
Tamron 70-180mm F/2.8 Di III VXD: Performance
Pairing the lens with Sony’s 61-million-pixel A7R IV would give it a tough test. One of my initial observations was how quick the lens was to focus, however extensive testing through the aperture range with the A7R IV’s Live View Display Setting Effect set to ON revealed that the lens was faster to focus at wider apertures than narrower apertures.
The reason for this is due to the camera instructing the lens to open its aperture fully to focus before the aperture blades close prior to the shot to be taken. With the Live View Display Setting Effect set to OFF on the A7R IV the lens focused perceptibly faster when smaller aperture settings were used.
The operation of the new VXD motor is silent and smooth, but some low-frequency noise of the aperture blades opening and closing was detected in use.
Inspecting images taken with in-camera compensation for shading, chromatic aberration and distortion turned on produced a pleasing set of results. Centre sharpness at the wide end (70mm) at f/2.8 is highly impressive, though it became apparent that corners are noticeably softer under close inspection. Corner sharpness improves right through the zoom range when the aperture is stopped down and used between f/5.6 and f/16.
Analysing images taken at the mid point in the zoom range also displayed a high level of sharpness in the centre of the frame wide open, with the sweet spot of edge-to-edge sharpness being located between f/5.6 and f/8.Users will be satisfied by the sharpness the lens resolves at the long end of the zoom too, though my tests revealed sharpness at the edge at 180mm isn’t quite as good as it is at wide and mid focal lengths.
No obvious curvilinear distortion was observed in real-world images between 70mm and 100mm, however I did identify pincushion distortion in shots taken at 135mm and 180mm. The good news is that this is fairly easy to correct manually in post processing.
The built-in lens profile that’s automatically applied to raw files does a fine job of correcting chromatic aberration. Even if you decide to disable in-camera lens compensation for some reason, you’ll observe little colour fringing in JPEGs.
Vignetting isn’t absent at wide apertures, but it’s also not overly offensive. Stop down from f/2.8 to f/4 and you’ll notice corner shading becomes less prominent and disappears completely by the time you reach f/5.6.