Just finished an environmental portrait shoot out on the street where I wanted to get the shop lights and street lights adding color to the backgrounds and had a late overcast sky
at the end of the day for the key light on her. I shot about half of it at 1600 ISO and was using my MKIII with the 85 1.2 set at an f2.5.
I can't stop loving that camera, I do mostly headshots now and table top, I was working for a company a year ago doing product shots,
all with that camera for both print and website, and there was a full frame IDsMKIII available but we just didn't need it, although I'd love to own one of those too. I really love this camera also because of the 1.3 is just wonderful with my two favorite lenses, the 24-70 which I also use a lot with a 12mm extension tube for extra detail work on products and the glorious 85II 1.2 which is ideal for perspective with the 1.3 crop when doing head shots. The autofocus is really wonderful on the 1D cameras, I always put the focus spot on the eye closest to camera and it just plain works really well. I know all the reasons for going back to full frame and have thought a lot about the new IDX until I read today about them no longer using the red focus point and the first thing I thought was oh good, an excuse to keep my MKIII- did I
mention that I love this camera LOL.