Lan Hikari said:
I noticed in the film that whenever Vader fired at someone, it took a couple to a few seconds before one of his bolts actually hit his target. When he fired at Luke Han got him before he could fire a shot that could hit him.
totsugeki said:
When Vader shot down Tiree (Y-Wing) and Red 12 (X-Wing in Red Leader's trio), he missed the first six shots. Vader manages only five shots at Luke before his wingman explodes.
It seems to take a while for a TIE's lasers to home in on the locked target.
Yes, you are right. I forgot about that.