Many of you probably did not know that in the last part of the famous saga "Star Wars", at one of the main characters - Darth Vader is not similar to each other costumes. I suggest you look at them and try to find the differences.
Star Wars: Episode IV - A New Hope
Star Wars: Episode V - The Empire Strikes Back
Star Wars: Episode VI - Return of the Jedi
Source:
www.501st.com