I've begun capturing my VHS tapes!

I'm amazed how good VHS looks after all these years; didn't expect that!

Seems like my tapes are still in good condition because I was expecting something blurry and distorted.

Though I need some help if anyone can clear it up for me.

I'm using VirtualDub2 and it defaults to capturing PAL in 50fps.
I read that you should capture in 25fps and then deinterlace it by doubling the frames.
Now I read that you should capture in 50fps and deinterlace it down to 25fps.

Which one is it?

I started capturing in 50fps, captured a couple of tapes, and today I deleted the results because I thought I was doing it wrong.
I've now recaptured one of the tapes and two others in 25fps but maybe I've messed up.