First and foremost, the 16-80mm’s MTF curves have a textbook appearance. Maximum resolution is in excess of 0.3 cycles per pixel from wide-open to f/11 at all focal lengths and the fall-off at smaller apertures is nicely progressive. Any resolution performance above 0.25 cycles per pixel indicates a well-mannered lens and it is clear that the Vario-Sonnar exceeds such expectations.

Second, chromatic aberration is all but invisible. It is true that taxing images (bare tree branches silhouetted against a bright sky) reveal colour fringes when examined at pixel-level but this manner of inspection is so severe that no standard zoom can escape totally unblemished.

Third, optical distortion is well-controlled. There is significant barrel distortion (6.3%) at 16mm, falling to an insignificant level (0.1%) at 35mm and then switching to a small amount of pincushion distortion (0.6%) at 80mm. That said, even when set to its minimum focal length the lens produces a very natural image quality in which distortion is not obtrusive.

Equally pleasant is the way in which depth-of-field is rendered: there is a particularly soft gradation from in-focus to out-of-focus regions despite biting sharpness in the former. This trick is something of a Carl Zeiss speciality and is one of the best reasons for choosing this lens over Sony’s own lenses.

Handling is good thanks to a wide zoom ring positioned closest to the camera body and a narrower manual-focus ring beyond. The zoom mechanism produces a continuous extension in the lens as it progresses from 16mm, through 24mm, 35mm and 50mm, to 80mm. There is a focused-distance window but no indications for depth-of-field.

It might be thought unfortunate that the maximum aperture is only f/3.5 and that the maximum aperture declines to f/4.5 at 80mm when there are other standard zooms that achieve and even maintain a maximum aperture of f/2.8. This might seem all the more disappointing when it is remembered that the Sonnar name is descended from “sonne”, the German word for “sun”, and was first applied in 1930 to indicate lenses that had a particularly wide aperture – but all of this overlooks the 16-80mm’s 5x zoom range, which is more than most of its competitors can offer. The only lens that triumphs on both counts is the Olympus Zuiko Digital 12-60mm f/2.8-4, but that retails for more than £600.