In this category the Canon 70-300 IS achieved the highest results of
all the previously tested lenses. One can easily say that vignetting
does not concern this Canon lens. Thus for a 70 mm focal length and the
wide open aperture, the vignetting is only 6%. The same great
results are found for 135 mm, where its level reaches only 7%. There
are also very good results for the 200 mm, where the light falloff in
the corners, with f/5.0, is only 9%. It is worth mentioning that
the level of 10% and lower is considered to be practically absent.
The weakest results, which do not mean bad at all, are for 300 mm,
where for f/5.6 the vignetting reaches 11% and for f/8 drops to 4%.
