Does Hot Rod PL use internal optical elements?
NO. The Hot Rod PL is NOT a relay lens system! It uses no power. There is no spinning or vibrating imaging plane. The system requires no back focus adjustment, or any optical focus adjustment of any kind. The Hot Rod PL does not introduce edge softening, vignetting or any porthole effect. The Hot Rod PL systems do have an adjustable flange depth using shims, which should only be adjusted/calibrated by a qualified lens/camera technician.