Hi all, first post here!
What I haven't seen discussed re: 5DM3 is the impact of higher useable ISO for lowlight shooters on the entire Canon L-series telephoto lens line. Currently, using Lightroom 3 noise reduction (@~35% slider), I can use 5000 ISO on my 5DM2 all day long, with very little noise impact on IQ. If the 5DM3 can get me a 2-stop ISO improvement, that equates to around 20,000 useable ISO. What that means, from a lens acquisition/ownership perspective:
A) I could work with a 70-200mm f/4L ($600/$1100 w/IS) instead of a 70-200mm f/2.8L ($2200/$2400) and still have sufficient shutter speed (1/200 or better) to freeze most subject movement, low light, no flash.
B) Similar comparison at 300mm for f/2.8L vs f/4.0L: $7300/5.2lb vs $1300/2.6lb. Savings=$6,000, plus no monopod required!
C) Even better, at 400mm focal length, with a 20,000 ISO, couldn't I get a 400mm f/5.6L for $1,200, instead of a 400mm f/2.8L for $12,000? I have neither budget nor the desire to drag an 8- to 11-lb monster around all night. With the 400mm f/5.6L, it's only 2.8 lbs, less than the 70-200 f/2.8L!
What I'm seeing potentially is the ultra-high ISO available in a 5DM3 (plus 1DX, potentially 7D2) making the incredibly expensive and heavy f/2.8L telephotos only being used by the elite/rich sports/outdoor shooters, allowing a lot of less-financially well-off shooters to produce still-great imagery using far less expensive and lighter f/4.0L-f/5.6L telephoto lenses.
Spending $1-2K on a 5D body upgrade from M2 to M3, just for the ISO alone, could/would pay for itself and then some, immediately in lens savings, wouldn't it? What am I missing?
Give me ISO! GE