Nikon 50mm f/1.8G AF-S - £180/$220
A major revamp of the 50mm f/1.8D lens, this lens is perfectly suited to digital photography. The antiquated aperture ring has been ditched in favour of a modern G-type design. More importantly for owners of cameras such as the D3100 and D5100, autofocus is available thanks to the addition of Nikon's Silent Wave system. Unlike the autofocus in some of Nikon's cheapest zoom lenses, it's a ring-type system that's practically silent in operation and offers full-time manual focus override in AF mode.
Other new features include an aspherical lens element, and the f/1.8G comes complete with a lens hood and pouch, both of which are lacking on Nikon's f/1.8D. The f/1.8G is a fair bit larger, but only 30g heavier, so still quite lightweight.
One feature that this lens shares with the older f/1.8D is the aperture diaphragm, which is based on seven blades in both models. This is pretty good for a budget lens, but isn't perfect - the blades themselves aren't very rounded, so small, bright objects such as streetlights take on a seven-sided shape.
Sharpness
As with the older Nikon 50mm f/1.8D, sharpness is extremely good throughout the aperture range.
Lab test
Sharpness at f/2.8: 1731
Sharpness at f/8: 1873
Sharpness at f/16: 1649
Fringing
Negligible at the largest apertures, colour fringing is only slightly evident at settings of f/8 and smaller.
Lab test
Fringing at f/2.8: 0.14
Fringing at f/8: 0.3
Fringing at f/16: 0.31
Distortion
There's only minimal barrel distortion, although the lens is beaten by the older D-type lens in this respect.
Distortion: -0.63
Image test verdict
Bokeh could be a little better, but image quality is extremely good, making the new G-type lens well worth the money.