Nikon AF-S 50mm f/1.8G
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) |
| Maximum aperture | f/1.8 |
| Minimum aperture | f/16 |
| 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 |
| Filter/attachment size | 58mm |
| 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.
