Yes they would think. Unless you cut the following dialog:
Piett: Shall I hold them?
Vader: No leave them to me. I will deal with them myself.Clearly they know.
No, Piett is asking because Vader obviously suspects something. Piett "was about to clear them."
Vader knows because he senses Luke. Luke is “endangering the mission.” If Luke wasn’t there, Han & Co. would have sailed right through with no problem.If you take the shuttle off course then it won’t be clear that Vader senses Luke, and not the shuttle off course.
They knows after Vader makes it clear.
I see what you’re sayin’, but I don’t think Vader sensing Luke would get lost if this change was made. It might change what initially alerts Vader, but the audience would still realize that he knows Luke is on board through the already existing visuals, editing and the direct dialog that says so.
IDK. Visual only tells me that Vader senses something, just as with Kenobi in TNH.
The dialog only suggests he believes they are rebels.
Luke mentions he might be the problem somehow, so it could be interpreted that Vader senses Luke, still would not feel like more than a vague possibility, and certainly not the first thing I would think of.
On the other hand, if they stay on course, than it can ONLY be Luke’s presence that alerts Vader. And everybody knows that instantly, mostly because the of lack of any other explanation.
Star Wars is simple.
(well the OT is)