Lightsabres?

I'm confused as to how strong they are meant to be exactly. At some points they will be extremely strong like when Qui-Gon was getting through that blast door with ease in episode 1. And yet episode 5 Luke hits vader in the arm and it makes a few sparks, it should have done way more than that like cut his arm of or leave a smouldering injury that would be really painful and yet it does hardly anything. So honestly how strong is a lightsabre?

I believe you can put the lightsaber on different power settings (said so in Dark Rendevouz), so Qui-Gon probably put it to the highest setting when cutting through the blast door, and Luke probably had it on a lower setting, and Vader could have moved almost instantly.

But he didn't move, thats what bothers me. It hit his arm and I think it would have done so much more even on a lower setting.

True, I will have to think of an explanation. Hmm, maybe because he was machine, and Luke didn't know he was that much machine, Luke pulled his lightsaber away from shock, that happenned in Rise of Darth Vader with one of the jedi fighting him, so maybe he did it too. Maybe?

Answer in SW terms: Perhaps Vader's armor was made partly of lightsaber resistant materials like cortosis, much like the Shadow troopers in the JK games. It would make sense, why not make Vaders suit able to resist Lightsabers? He was purging the Jedi for a good while after ROTS, he would need it.

Answer in reality: Its just a general inconsistency in the movies is all, just small plot follies. Like in ROTJ when Luke is hitting the hand rails while fighting Vader (right before he cuts off Vader's hand) the saber does not go through the rails either (and it should have)

Also, in ESB Luke and Vader's saber go through a rail, then Luke hits Vader's shoulder and it does nothing, then Vader slices through a REALLY think metal thing before he cuts off Luke's hand. All in the same scene, they arnt changing the power settings of the saber through the fight, especially not in a span of 30 seconds. Its just a stupid blunder is all.

Remembrer also that the licht saber are rechargable, maybe if you put it in the highets setting, the battery dies sooner, or if your battery is low the power of the saber is deminished.

But in the comic STar Wars Purge Tsui Choi cuts off Vaders hand, Bultar Swan injures his leg, Jastus Farr injures his back and Tsui Choi before he dies he throws his lightsaber and it scrpaes VAders helmet It is not made of cortoisis alloy

I didnt say it was made OF cortosis. I said

"Perhaps Vader's armor was made partly of lightsaber resistant materials like cortosis"

This means that lightsbabers CAN cut through it, (we've seen them do it on all sorts of occasions) but maybe its cortosis weaved or something. Just so it would take a full swing in order to penetrate his armor completely. Luke's swing in ANH is more of a quick strike, had he swung fully it would have gone through. The shadow troopers in the JK games have cortosis suits, but they arnt made fully of cortosis, otherwise they'd just be metal suits, which they arnt. Vaders suit wouldn't be fully made of it. But it makes sense it would be semi-lightsaber resistant. Which it appears to be in ESB.