I like the 24-70mm f/4 IS very much. I originally bought the f/2.8 MkII, it is a fantastic lens, however I need the IS for low light event shooting.
I'm confused by how much some people lean on IS for low-light photography. Stabilizing only accounts for one problem of low-light photography. It compensates for camera movement. It's great at doing that, but it can never compensate for subject movement. For me, shooting slower than 1/60th is not an option for available light event shooting. (Of course, with flashes, who needs IS anyways?)
No need for confusion. What works for his particular case might not apply to you. All light event shooting is not exactly the same. It really annoys me how some pro-s diss standard or wide angle zooms with image stabilization (a review of the 16-35VR by Jared Polin comes to mind). This person has tried out the 2.8 II and chose the f/4 IS over it, so obviously it works better for him. Moreover, I cannot accept that Canon didn't do prior market research and just brought out a lens nobody cares for. There cannot be one standard answer for everything.
Please re-read my post, or closely read my attempted clarification below.
when you are shooting for 10 or 12 hours fatigue becomes a very real issue and having an IS lens provides a significant advantage here by compensating for the additional camera shake that enevitably comes once fatigue has set in. some people forget this or dont shoot enough to experience it
Look, I was only pointing out that a
stabilized lens cannot compensate for a moving subject, which is big part of event photography, is it not? I know how wobbly the arms get during long shoots, and I know how good stabilizing is at doing what it's made for, but it's not a 100% cure-all for all low-light photography.
If Canon comes out with a stabilizer that can stabilize a moving subject, let me know, but until then, I make the claim that a wider aperture is more useful for low-light
event photography than the same focal range with a smaller aperture and stabilizer. Of course, I'm only talking about cases where it's dark enough that you approach the reciprocal rule. There are plenty of "low-light" situations where either lens will perform great.
Or to put it another way: stabilizers are designed for when you're shooting near the reciprocal shutter speed, but when that shutter speed approaches 1/50th, subject motion blur becomes an issue. In this case, a wider aperture that lets you shoot faster than 1/50th is more useful than a stabilized lens at a narrower aperture.
That is why I "diss" medium and wide stabilized lenses. They're relatively useless for shooting anything that moves in low light.
(Disclaimer: Again, this is only for stills. Video benefits much more from a stabilizer at any focal length.)