setDeadzone() bugs when not in the center

[robinvd]

relevant part of the code:

  camera = Camera(0, 0, window.width, window.height)
  camera:setFollowStyle(nil)
  local w, h = camera.w/16, camera.w/16
  camera:setDeadzone(window.width / 2 - 50, window.height * 3/4, 100, 50)
  camera:setFollowLerp(0.8)
  camera:setFollowLead(1)

giving me this output:
Imgur