• Mirror lock up is important at 1/3 second.
  • I'm assuming autofocus, try manual focus to see if it improves.
  • It's going to be a little soft at f/4 especially if you're not aligned perfectly to your target. try f/8 or f/11
  • What are your other settings ISO, RAW, JPG, Contrast, Sharpness, White balance, etc.
  • What was your distance from the sensor to the target
  • Need Data []