no , you are supposed to do just but now you know you're going to get attacked, drink gadwell or swallow before you pull out the crystal.
and maybe place a trap or 2 as well, it wont damage them much but will slow down their initial attack giving you time to roll away.
and use dancing star and dragon's dream bombs if you have them. Harpies catch fire easily and it does a lot of damage to them.

they are not that hard... just put Quen, roll outside and spam bombs on them ^^

You should.
Option A:run around in circles between that big "chamber" and the corridor connected to the three other leading to the other crystals while hitting and dodging backwards as you are running and they are chasing.Managed to do this first try,just using my sword and aard.
Option B,which I did on my second playthrough cause I couldnt be bothered again:run in circles but just until they are grouped together in a tight space and hit them with some bombs with incineration.

KILL THEM ALL AND TAKE THEIR STUFF
http://www.filehurricane.com/photo-viewer/2153



. . helps if you kept all those snare traps you found in Chapter 2 :P

Bombs and or run to a choke point.

There are other crystals that you need to pick up around the area and put into the projector.

Use bombs. Sometimes the game spawns way too many monsters.

I'm stuck too, because the projector won't work...
I've collected all available crystals but cannot view the dreams to identify the dragondream one. Seems to be a bug in the game here....???
When i try to 'view dream' nothing happens.
[ My Projector won't work!! What am i doing wrong? Please help!

I've never seen an issue with it - you click on it (the projector), then for some reason you have to click again, and it gives you a menu where you can play various dreams. You're getting the menu but the cutscenes aren't playing?

Killed them easily with the silver sword. Drink some potions, use quen often, and only use heavy attacks (whirl lvl2 necessary).

1) Make a few Dancing Stars (three or more on hard)
2) pick up the crystal
3) roll out from the middle of the harpy pack
4) get to a choke point (in the disc 'room' there should be a narrow door-like path to another 'room')
5) knock down the first harpy with Aard to act as a roadblock (even better if you have improved Aard)
6) BIRD BBQ

I was enjoying this game immensely until this quest.
Haven't played for over a year because I couldn't kill the bloody harpies.I'd die in 10 seconds.
No way of beating them and I'm playing on easy.

P.S. had another 10 tries or so
Get killed in 10 secs.
This quest killed the enjoyment of the game dead for me.

Now I can't remember how to use the signs.
I went to controller options and there is nothing there to tell you what each button on your gamepad does.

Argh.

P.P.S. I FINALLY FOUND OUT HOW TO KILL THESE HARPIES.
At last I can move on.

Thank you BatistutaSRB who suggested the silver sword combined with Aard.


I used your tactic also by running around in circles and knocking them off one by one.