chaman wrote:
The brightness you see is sometimes due to a vignetting effect the lens may have. When corrected the vinetting goes away and the overall image may appear brighter. It happen with the Canon 24-105mm Mark I L lens too. I sometimes let the correction takes place sometimes not, depending on the image.
Now I understand, its tempting to leave the correction out . I'm making the correction then applying a vignette in some cases. Fell ever so slightly mad.