I love the Solaris movie by Tarkovsky, but I have no idea how faithful it is to the book. have you read it Kal?
Yes, it is quite faithful, as opposed to the 2002 American version.
i tried reading the star diaries but couldn't get into it. it might've just been the german translation beïng bad though idk
Lem is difficult to translate, although Michael Kandel did a marvellous job with English translation (so great that if there was a Nobel Prize in Translation, he should've got this). I can't speak for the German translation.