Nikon has announced a new AF-S Nikkor 50mm f/1.8G lens with an aspheric element.
A small and light 50mm f/1.8 is ideal for walk-around shooting— comfortable to carry, and innocuous in use. The f/1.8 aperture is plenty fast for today’s DSLRs, and affords excellent low-light ability.
The key with this new lens is image quality, and there the 50/1.8G appears to have gotten some attention from Nikon’s lens designers. Given the outstanding 24/35/50/85 f/1.4 lenses, if the 50/1.8G falls into that pedigree, then it ought to be an inexpensive high performer. It is much easier to build an f/1.8 lens than an f/1.4 lens (and to reduce off-center aberrations), and it has an aspherical element as well.
When the 50/1.8G becomes available, I am planning on a comparison between it and the 50mm f/1.4G.
Weak points include a 7-blade aperture instead of 9 rounded blades, and a close-focusing distance of only 1:6.7. Photographers for whom f/2.8 is adequate might consider the Nikon 60mm f/2.8G instead or in addition for its close-focus abilities.
|Nikon AF-S Nikkor 50mm f/1.8G specifications|
|Focal length||50mm (nominal)|
|Lens construction||7 elements in 6 groups, super integrated coating, 1 aspherical element|
|Angle of view||47° (31°30' with Nikon DX format)|
|Maximum reproduction ratio||1:6.7|
|No. of diaphragm blades||7|
|Diameter x length (from lens-mount flange)||Approximately 2.8 X 2.1 in (72.1 X 2.4mm)|
|Weight||Approximately 185g g/6.6 oz|
|Supplied accessories||58mm Snap-on Front Lens Cap
LC-58 Rear Lens Cap
LF-4 Bayonet Hood
HB-47 Flexible Lens Pouch CL-1013
MTF (modulation transfer function, e.g. contrast at resolution)
Nikon’s MTF chart for the 50/1.8G at f/1.8 suggests a lens with very high contrast on coarse structures (overall contrast), along with very high central sharpness for fine details, falling off quickly but gracefully to the edges and a sharpness dip into the corners, possibly a field curvature effect, or possibly the result of aberrations. Regrettably, Nikon does not supply MTF for f/4 or f/5.6.