Skywise said:
One question I haven't seen answered - I'm heading out to Disney in a few weeks and planning on videoing the fireworks with my 6D and 16-35 F2.8II. I've used it before with great success but I'm tempted to switch to the F4 version for regular photos plus the IS might be more advantageous while videoing but I'm leery of losing the F2.8 for the fireworks lighting. I used to video them with a T4i and an EF-S 10-22 and the F3.5 never quite looked as good as shooting with the EF-S 17-55 F2.8 (but I preferred the wide angle of the 10-22). That's what I'm using for comparison and I'm not sure it's fair given that I"m comparing a cropped to FF sensor as well.
How are the low light capabilities of the lens compared to the f2.8 version?
You know the answer I think.
The 16-35 f4 is one stop less then the 2.8. So the same you did find on the comparison between the 10-22 and the 17-55, will here be the same. The 10-22 is an excellent lens on a crop body, but the f3.5 is not the strongest side of this lens for doing low light.