LensTip.com

Lens review

Yongnuo YN 50 mm f/1.8

26 January 2015
Szymon Starczewski

8. Vignetting

First let’s check how the tested Yongnuo YN 50 mm f/1.8 fares when it comes to vignetting on the small sensor of the Canon 50D. Appropriate thumbnails are presented below.

Canon 50D, f/1.8 Canon 50D, f/2.0
Yongnuo YN 50 mm f/1.8 - Vignetting Yongnuo YN 50 mm f/1.8 - Vignetting


The vignetting can be noticed only near the maximum relative aperture. By f/1.8 it amounts to 22% (-0.73 EV) and it decreases to 18% (-0.59 EV) after employing f/2.0. After stopping down the lens to f/2.8 the vignetting isn’t bothersome at all, reaching just 7% (-0.20 EV). It’s worth noticing these results are by 1-3% lower than those of the Canon EF 50 mm f/1.8 II.

- - - - - - - - - - - - - - - - - advertisement - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Now let’s see how the situation changes when you pass to full frame.

Canon 5D III, f/1.8 Canon 5D III, f/2.0
Yongnuo YN 50 mm f/1.8 - Vignetting Yongnuo YN 50 mm f/1.8 - Vignetting
Canon 5D III, f/2.8 Canon 5D III, f/4.0
Yongnuo YN 50 mm f/1.8 - Vignetting Yongnuo YN 50 mm f/1.8 - Vignetting


Here the problem is very serious indeed. We hoped that a bit bigger physical dimensions of the Yongnuo would allow it to correct the vignetting better than the Canon. Unfortunately the differences are minimal and not always favourable for the tested lens. At the maximum relative aperture the brightness loss in the frame corners amounts to 61% (-2.70 EV) – it is a huge value. By f/2.0 the situation is hardly better as our measurements provided a result of 56% (-2.37 EV). The vignetting is still noticeable by f/2.8 where it reaches 32% (-1.13 EV). A low level of that aberration can be observed only by f/4.0 where it is 18% (-0.56 EV). The problem is eliminated almost completely by f/5.6 where we got a result of 10% (-0.29 EV).

In this category the Yongnuo, like the Canon, didn’t exactly distinguish itself.

Yongnuo YN 50 mm f/1.8 - Vignetting