Lens review

Tokina AF 193 19-35 mm f/3.5-4.5

8. Vignetting

Taking into account the fact that we deal here with a full frame design, the Tokina 19-35 mm doesn’t deserve much praise. When we use it on small APS-C/DX sensors the problem of the light fall-off in the frame corners won’t be especially serious although it is still noticeable.

The biggest problems we will encounter near 19 mm focal length. At the maximum relative aperture the vignetting reaches the level of 28% (-0.95 aperture value). On stopping down to f/4.0 we don’t see the situation improving because the brightness loss in the frame corners is still as much as 24% then. By f/5.6 we deal with the value of 18% and by f/8.0 – 12%. Only by f/11 we can reduce the vignetting to an imperceptible level of 8%.

A better situation is at 28 mm. By f/4.0 the light fall-off amounts to 23% (-0.76 aperture value) and on stopping down to f/5.6 it decreases to 15%. By using f/8 aperture we can get rid of the problem because the level of this aberration decreases to 10%.

The nicest performance in this category can be noticed at 35 mm. At the maximum relative aperture the vignetting reaches 20% (-0.63 aperture value) and by f/5.6 it decreases to 13%. On using f/8 aperture the light fall-off in the frame corners is just 8%.