ed rader wrote:
folks who do this for a living aren't hung up on whether a lens is f4 or f2.8 .... they want the best tool for the job.
...which sometimes means the difference between f/2.8 and f/4.
at a wedding i'd think you'd want to be unobtrusive which is impossible if you have to shove the lens in someone's face to get a picture.
ed rader
I'd crop a tiny bit, and get the same FOV. An 85 over a 24-70 isn't giving me enough of an advantage in length to have that on instead of zoom, giving up versatility. True...you'll no doubt get a touch of sharpness, but it's not always worth it.
If you mean the difference between 105mm and 70mm, I still wouldn't do it. Especially at a wedding. I'd always take 2.8 over f/4 with IS. I don't want to chance blurring the bride. The 2.8 will always freeze action better. Twice the shutter speed.
However, like I said, there's sometimes when you need a blurry shot, or nothing. Those are the times I would take the 24-105.