slask said:

Anakin's real look in his 40s is the one we see when Luke removes the helmet. His ghost had an unreal appearence, so Lucas decided to show him as he appeared last time he was by the light side.

A vast oversight on his behalf, because the last time he was alive (on either side) he looked like Sebastian Shaw, and Obi-Wan and Yoda's ghosts look exactly as they did when they died. And don't tell me "he metaphorically died when he turned to the dark side" - again, he looked like Sebastian Shaw when he redeemed himself - see what I'm saying?