After more than 30 years, Nikon has changed the optical design of its 50mm f/1.8 lens. But how does the new model compare to its predecessors? Richard Sibley investigates
There are three main benefits to using an f/1.8 lens: the large aperture allows you to shoot in low-light conditions; the large aperture will produce a very shallow depth of field, which can be used creatively; and the aperture can be closed to f/2.8 or f/4 for optimal performance, but continue to offer a shallow depth of field.
Image: The Nikkor f/1.8G lens is ideal for low-light portraits
While half the fun of 50mm f/1.8 optics is using them fully open, this is also when they will optically be at their worst.
Looking at all four of the Nikkor 50mm f/1.8 lenses, it is clear to see the evolution in the lens design. The new G series optic has the least coma and chromatic aberrations of all of the lenses – presumably is a result of the new aspherical element.
Image: The Nikkor 50mm f/1.8 lenses: Top Left: AF-D. Top right: the new G series. Bottom left: original AF. Bottom right: manual E series
The improved multi-coating of the 50mm f/1.8G has also boosted performance, adding a good level of contrast compared to past lenses. This has helped to increase image definition, again, particularly when one is shooting at f/1.8.
It is, of course, image sharpness that all lenses will be judged by, and in this regard the 50mm f/1.8G performs extremely well. Tested using the 24.5-million-pixel Nikon D3X, the new lens resolves around the same amount of detail as its predecessor but produces better contrast and less chromatic aberration at wider apertures. As you would expect for a fixed-focal-length lens, it is extremely sharp, picking up very fine details with impressive clarity.
However, the new lens does have a few slight flaws, including a little more barrel distortion than with previous versions. This should not be too much of a concern for photographers, especially those using cropped DX-format (APS-C-sized) sensors, as these use the centre of the lens where any curvilinear distortion is far less noticeable. The distortion is also very easily corrected in software.
Vignetting is also present when the lens is at its widest aperture, but once again it is not severe and is easily corrected, so it will not be an issue for those shooting with DX-format Nikon DSLRs.
All of the resolution chart images were taken on a 24.5-million-pixel Nikon D3X. Whilst the lenses can resolve an almost identical resolution at their optimum aperture, the latest G series lens is slightly sharper when fully open, and shows less chromatic aberrations and coma. However, the other lenses all stop down to f/22, compared just f/16 on the new G series lens.