How did Vader know?

I think this quote from Lucas pretty much proves my point that Lucas didn’t have Vader planned as Luke’s father when the first movie was made, which, from a writing point of view, is why there are so many logical inconsistancies (from http://www.videoeta.com/news/1359):

Also, Vader wasn’t originally designed to be a “walking iron lung”. According to my ILM art book, an artist drew a lightsaber confrontation between Vader and Luke or Ben, taking place in an airless environment, with both sides with space lung stuff on. Lucas liked so much how Vader looked in his suit that he came up with a back story to justify having Vader look like he does.

(I know way too much about Star Wars to lead a healthy life.)

Tried to post yesterday, but computer wouldn’t let me.

(Skott) They also have a continuity problem with Leia. The first film makes sense. Then she and Luke are sister and brother, and there’s no reference to the scene where she kissed him. She could have “always known” for about three years because they worked together in the rebellion. Vader doesn’t recognize his daughter in the interrogation room. And how does she get raised on Alderaan while he’s a farm boy on Tatooine? Who raised her?

While no attempt was made to hide Luke they did hide Leia. I don’t know if they mention Bail Organa, whose name she sports, in the original trilogy though.

I have another idea: I don’t know how Vader learns that Luke is his son, but when he does so, he then concocts the scheme of overthrowing the Emperor so he and Luke “will rule the galaxy as father and son” as he explained in ESB.

TwungTister: As for Leia, Vader didn’t even know she existed until he read Luke’s mind in their climactic battle in RotJ, so it’s no wonder he did not recognize her while torturing her in ANH. Also, I think it’s implied that it was Ben who took Luke and Leia to separate planets. Perhaps Ben saves the life of Senator Bail Organa (Jimmy Smits) in Ep. III and the Organa family raises Leia in return.

According to imdb, James Earl Jones returns as the voice of Darth Vader in Ep. III. Also, Hayden Christensen is credited as playing both Anakin and Darth. Christensen is 6’1" , but David Prowse is 6’7". How are they gonna make Christensen tall enough?

I understand lots of tape was involved.

I understand lots of tape was involved.

As for the height disparity between Anakin and Vader, this one is actually pretty easy and doesn’t require a canon violation (as if that would deter Lucas for more than a nanosecond). In ROTJ, Luke slices off Vader’s hand and we see sparks and such, suggesting Vader had cyborg parts. Whatever personal disaster befalls Anakin in the upcoming movie (the ROTJ novelization describes it as falling into a “molten pit”), it’s easy to assume his legs get replaced as well, increasing his height.