« on: January 20, 2014, 09:34:20 AM »
If I understand it correctly, it's your typical Imatest result like on Photozone. The ordinate is LW/PH.
I can't tell if it's center and edges, or center and corners, or center and average. But they go on pretty close, so it doesn't really matter. It's just good
I think they used a 5D MK III. As an approximation based on other available imatest data, 600mm f/8 is very, very close to the 100-400 L at 400mm f/5.6. Only very slightly worse, if you consider the error margin.
Here's my problem with that chart. Unless I'm doing the math wrong or not understanding what this chart means (certainly possible since it's in Chinese), the f/32 numbers are beating the diffraction limit, calling the entire thing into question.
From what I've seen of visual tests, it loses more contrast than detail at 600mm and f/6.3, and gains it back in huge steps from f/7.1 to f/8. That's probably okay for me as I would use this as a daylight airshow lens, and switch to my 70-200/2.8L IS II (with and without TCs) if the light got lower.