i am looking at the comparison of canon 10-22 & tokina 11-16
when i move in the pointer, beside seeing changes to the numbers & lines, i notice the base color of the chart (white) also changes in the tone.
for example, when set to 12mm, at f4 & f8,
1) canon 10-22,
tone for "centre" chart is lighter than the "mid-frame",
tone for "mid-frame" & "corner" is similar.
2) tokina 11-16
tone remains almost unchanged between "centre" & "mid-frame",
tone between "mid-frame" & "corner" is similar.
what does that means? can i say the light fall off of the tokina at 12mm, at both f4 & f8 is much lesser than canon?