Thank's Mike
Below is the link to the RAW file; it's about 21mb.
http://filez.bordermail.com.au/io7veh9
If anyone has a 6D can they just do a test for me.
I shot that image in RAW, 4min exposure iso 800 using 16-35mm EF L Canon lens. Not that the lens would mean anything. RAW or processed all images have the same pattern.
Canon rep just tried to tell me its noise from having the shutter open for 4 minutes. Come on guys.
Regards
Carl