Wide open, f/2.8 at 24mm I expect a lens this expensive to have abolutly no vignetting.
The 600mm f/4L IS II costs $13,000 and has about 1.5 stops of vignetting wide open.
The 24L II is $1500 and it has 3 stops of vignette. O_o
This is typical of a board with "Rumors" in its name.
We start by talking about the 24-70mm f/2.8 L II shot at 24mm, jump to the 600mm II and then it somehow turns in to the 24mm f/1.4L II
The New Rumored 24-70 2.8L III will have Zero vignette at all focal lengths and perfect IQ. It will weight in at a reasonable 500 Grams and a MSRP of 1299$ including canons all new 7th generation Image Stablizer providing 8-stops of compensation.
This could be a "rumor" right?
Can I pre-order now?
Sure, If you've got a spare billion dollars for the R&D.