I have a retail disk version of STALKER SoC, and purchased the GOG version about a year ago.

I installed the GOG version and set all the graphics settings in the in-game menu exactly the same way I have them in the retail game (everything max), however I immediately noticed that the GOG version had really ugly shadows, much worse than the retail game. So I compared the user.itx files from the retail version to the GOG version, and they're completely different, despite the game's being configured identically in their menus. If I put the retail user.itx in the GOG game, it looks much better.

I've tried deleting the GOG user.itx and letting it regenerate it, but it always ends up different to the retail one.

Both instances of the game are the same version/patch.

What's going on?

First ive heard of this. Sadly right now ive a fried hd or id check myself. Can you post a screen comparing them

These are the significant ones:

http://i.imgur.com/EgKjFnv.png

Thank you for showing the differences.
I don't have the retail version installed right now, is it possible to just change the user.itx?
Are the other changes that need to be made to make look as the retail version?

I wonder whether [STEAM] Shadow of Chernobyl also has different default settings with the GOG version than it does for retail.

I remember something about this, though I don't remember the specifics I checked my game updates folder and found I had stored the retail user.ltx file with some screenshots.

Incase anyone wants to check out the screenshots..
http://imgbox.com/g/JEo6VUSgIM

Also incase anyone wants the retail user.ltx but doesn't want to or can't install the retail version..
http://paste2.org/mK0OcLvc

Or just download the file I had saved with the user.ltx and screenshots in..
http://en.file-upload.net/download-10631222/Stalker-Retail-user.ltx.rar.html

Sorry I don't remember the specifics but it's out there somewhere if you feel like searching, that's probably where I saved the screenshots from as I didn't take those myself.

Edit, someone had this problem again and managed to remember it this time, edit "user.ltx", "r2_sun_near_border = 1".
The shadows may still be a bit strange on the very edges in which case you could try increasing it a little more in fractions.