The thumbnails showing the vignetting results of the tested lens at different focal lengths and apertures are presented in the chart below.
18 mm, f/3.5
18 mm, f/5.6
50 mm, f/5.3
50 mm, f/5.6
100 mm, f/5.6
100 mm, f/8.0
200 mm, f/5.6
200 mm, f/8.0
300 mm, f/5.6
300 mm, f/8.0
At the shortest focal length and with the lens wide open you have to take into account the loss of 41% of light in the frame corners (−1.52 EV). That’s a lot. In the case of the Tamron 16-300 mm the value we got at 16 mm and on a bit smaller sensor of the Canon 50D amounted to 35%.
On stopping down to f/4.0 the vignetting decreases to 35% (−1.25 EV). The problem becomes moderate by f/5.6, reaching 22% (−0.73 EV). Further stopping down has a very weak influence on the vignetting because by f/8.0 and by f/11 we got respectively 16% (−0.50 EV) and 15% (−0.48 EV).
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.
The middle of the focal range is characterized by a complete lack of vignetting problems. The best situation you see at 50 mm where even at the maximum relative aperture it would be difficult to spot any significant light fall-off, which value is only 9% (−0.27 EV). It increases a bit after passing to 100 mm where, by f/5.6, it amounts to 16% (−0.52 EV), but then by f/8.0 it decreases to a mere 7% (−0.22 EV).
At 200 and 300 mm focal length you see a very similar performance. In the case of the former, by f/5.6 the brightness loss in the frame corners amounts to 27% (−0.9 EV) and by f/8.0 it decreases to 17% (−0.53 EV). The vignetting becomes imperceptible by f/11, reaching just 10% (−0.29 EV). At the 300 mm focal length and the maximum relative aperture you have to take into account losses of 29% (−0.98 EV) of light; then on stopping down to f/8.0 the vignetting level decreases to 17% (−0.53 EV) and after employing f/11it amounts to 9% (-0.26 EV).
