The serious wedding and landscape users will be maxing out at iso800, probably 100/200 most of the time so iso 25600 is only really for some sports snappers
Serious Wedding photographers maxing out at iso 800, you have got to be kidding me. The ambience of a low light shot is way more valuable to me than if there is some noise.
If you think I am a nobody then at least read what Jeff Ascough wrote in Feb 2010. I quote Jeff Ascough "I’ve been shooting with the EOS-1D Mark IV for about three months now. This is the time of year when there are quite a few candlelit wedding ceremonies and receptions, so I’m often shooting events that are taking place in near darkness…
The camera’s performance is really quite staggering at higher ISOs, especially 6400 and 12,800, as the image quality is just gorgeous. There is little noise, no banding and, for a crop sensor camera, the resolution is very good. I have to admit that I probably wouldn’t use the H1 setting (12,800) on the 5D Mark II but I’d happily use 12,800 on the 1D Mark IV all day long."http://cpn.canon-europe.com/content/news/jeff_ascough_blog.do
or Brent Stirton
"I shot this Canon [EOS 5D Mark III] up to [ISO] 25,600 and it was, to my mind, at least as good as the file coming out of the EOS 5D Mark II at 1200 to 1600. So that’s a huge leap forward for me.”http://cpn.canon-europe.com/content/education/technical/brent_stirton_shooting_eos_5d_mark_iii.do