Quote Originally Posted by Jayson View Post
I stopped the lens up to f/11 to regain a little sharpness back with the hopes I didn't ruin it too much with diffraction which starts at about f/6.9 on this sensor.
Did it show f/8 wide open with the stacked TCs? IIRC, only one is reported, so it shows f/5.6,wide open, meaning if you set it to f/11, you're really at f/16.