A few recent reviews.....
http://www.ephotozine.com/article/nikon-af-s-nikkor-20mm-f-1-8g-ed-lens-review-26372
Pros :
- Very sharp when stopped down
- Relatively compact and lightweight
- Silent focusing
- Low distortion for an ultra-wide angle lens
- Good value
- Nano-Crystal optical coatings
Cons :
- Falloff of illumination is quite severe at max aperture
- Could be sharper at maximum aperture
This new lens from Nikon is a nice upgrade to the previous 20mm f/2.8D, which has a design that dates back to the early nineties. The fast f/1.8 aperture is great for low light shooting, and even though sharpness may not be of the same level as Nikon's top lenses at maximum aperture, it is still very usable.
The lightweight, yet robust construction lends itself to being used in harsh environments, as well as meaning that it balances well with Nikon's most compact SLR bodies.
and another here :
http://www.lenstip.com/2105-news-Nikon_Nikkor_AF-S_20_mm_f_1.8G_ED_-_lens_review.html
Summary :
Pros:
- very good image quality in the frame centre,
- good image quality on the edge of the APS-C/DX,
- slight chromatic aberration,
- properly corrected spherical aberration,
- moderate distortion,
- low coma level in the corners of the APS-C/DX sensor,
- negligible astigmatism,
- not very bothersome vignetting on the APS-C/DX,
- silent, quick and accurate autofocus.
Cons:
- too much plastic and slacks in the casing,
- a bit too weak image quality on the edge of full frame,
- distinct coma in the full frame corners,
- work against bright light could have been better,
- significant vignetting on full frame.
The tested Nikkor can by only compared to the Sigma 20 mm f/1.8 EX DG Aspherical RF, a lens which could be called good over 10 years ago; currently our demands are noticeably higher and the performance of the Nikkor is the proof. The Nikkor managed to beat the Sigma in practically every testing category – even the vignetting, despite its smaller physical dimensions, was corrected slightly better (still keep in mind the fact that our conclusions are based only on the smaller sensors results because we didn’t test the Sigma on any full frame camera).
.... Cathay always seem to have the highest prices or quote list prices IMO ( unless they import that brand then expect 10-15% off the list... so go TK Foto or SLR Revo....
