This review of the Yongnuo YN 50mm f/1.8 full frame lens for Nikon DSLR cameras (additional coverage of that lens can be found here) is by Arkadiy Shapoval from radojuva.com:
YONGNUO 50mm 1:1.8 (YN50mm F1.8N). The lens is captured on a film SLR Nikon EL2.
Important: Please note that the Yongnuo YN50mm F1.8 lens model, in versions for Nikon and Canon, looks very different from one another. Usually, third-party lenses such as Tokina, Tamron, Sigma, Carl Zeiss, etc., have a very similar barrel design for versions for different systems.
In brief
Yongnuo 50mm 1: 1.8 (YN50mm F1.8N) is a very inexpensive fast nifty fifty lens from the Chinese manufacturer Yongnuo Digital. The lens copied the original Nikon 50/1.8G barrel design and the optical performance of the Yongnuo Lens EF 50mm 1: 1.8. In general, it is not bad. First of all Yongnuo YN50mm F1.8N is interesting to owners of Nikon D40, D40x, D60, D3000, D3100, D3200, D3300, D3400, D5000, D5100, D5200, D5300, D5500, D5600. For those who have a Nikon camera with a built-in focus motor, there is a remarkable and inexpensive Nikon 50/. 1.8D (as well as a million of its old sub-versions).
The creative and practical potential of this 50 mm lens is difficult to overestimate. It is suitable for a wide range of photo tasks. Photographers often use it as a portrait lens. A lot of them just want a high-speed fix, in addition to their kit lens. The aperture F/1.8 is 3.5 stops wider than the aperture F/5.6, which is used in the ‘slow’ kit lenses at 50 mm. In a numerical equivalent, this means that the Yongnuo 50mm 1:1.8 (YN50mm F1.8N) is 10 times faster, for example than Nikon 18-55/3.5-5.6 kit lens (which uses a maximum relative aperture, equal to only 1:5.6, for 50 mm). Counting in the difference of the relative aperture is quite simple: (5.6*5.6)/(1.8*1.8) = 9.679, rounded to the value ’10’.
