I love my 24-105 f.4. That being said, will the mkII series do much better in low light with the 24-70 f/2.8?
I shot the 1dmkIIs for the first time vs my 5D on Saturday night. F/4, 580EX for focus aid. It was not impressive. I was kinda shocked but FM warned me. I am thinking of using that feature where the cam uses the surrounding points as well. But will the f/2.8 make a big difference? How about the 1dmkIII? I might be able to convince myself to use the 5D/1DmkIII combo and sell the 1dsmkII.
your 1ds2 should beat your 5d focusing all the time no matter what lens you use. with that said f4 for low light is kinda rough. even 2.8 sometimes is not enough. You need 1.2, 1.4, 1.8 for really low light. I have never had a problem though with my 1ds2 and any 2.8 lenses that I have.
I would not get rid of the 1ds2 I would swap the 1d3 for some glass.
Doug
At a certain level of light, the jump from 4.0 to 2.8 makes a massive difference in focusing ability. The same applies to the jump from 2.8 to a 1.x aperture.
The center focus point on the 1 series prior to the mkIII's and in low light is more accurate but slower than the 5D according to Canon's Chuck Westfall. Got to do with smaller AF sensor and the need for more accuracy checks. This has been well documented. I've played with a 1D mkIII next to my 5D's, f4 speed is about a zillion times faster with all focus points but especially the center point. f1.8 lenses were a bit faster (and probably a lot more accurate) but nothing worth switching for IMO.
I'm now having dreams of a pair of 1Ds mkIII's for that incredible focus, loads of cross points and spot metering linked to the focus point. Business can't begin to afford it though, it would be nice, make my life easier, but I've shot weddings with a pair of 5D's for 4 years and still managed to do the job
