Canon EF 50 mm f/1.8 STM review - Vignetting

Have you rated your lenses yet?

Canon EF 50 mm f/1.8 STM

11 July 2015

Arkadiusz Olech

8. Vignetting

Let’s check how the Canon 1.8/50 STM manages vignetting on the smaller Canon 50D sensor first; the appropriate thumbnails are shown below.

Canon 50D, f/1.8	Canon 50D, f/2.0

At the maximum relative aperture the vignetting is moderate, reaching 22% (−0.72 EV). That aberration decreases to 17% (−0.55 EV) on stopping down the aperture to f/2.0 and disappears almost completely (6% and −0.19 EV) after employing f/2.8.

Please Support Us

If you enjoy our reviews and articles, and you want us to continue our work please, support our website by donating through PayPal. The funds are going to be used for paying our editorial team, renting servers, and equipping our testing studio; only that way we will be able to continue providing you interesting content for free.

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

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

Now it’s time to see how the situation changes when you progress to full frame.

Canon 5D III, f/1.8	Canon 5D III, f/2.0

Canon 5D III, f/2.8	Canon 5D III, f/4.0

The problems become serious here. At the maximum relative aperture the light fall-off in the frame corners reaches as high as 61% (−2.75 EV). On stopping down the aperture to f/2.0 you are able to decrease it to 56% (−2.34 EV). Also by f/2.8 you won’t have any problems with noticing that aberration because it amounts to 32% (−1.09 EV). Bad performance ends by f/4.0 where the vignetting decreases to 15% (−0.48 EV). By f/5.6 that aberration becomes practically imperceptible (10% and −0.32 EV).

As you see a slight decrease of the size of the casing and the diameter of the filter plus an addition in a form of the STM motor didn’t make the vignetting level increase significantly. The results of the tested lens are by about 1% higher than those of its predecessor but, taking into account the measurement errors of 2-3% you can’t really talk about noticeable differences here. Still the performance of both Canons in this category can hardly be called good. It’s worth reminding here that both Nikkors, the AF 1.8/50D and the AF-S 1.8/50G, at the maximum relative aperture had the vignetting near 41-44% - they fared much better.