How to Turn Off NR?
I set "High ISO NR" to "Off", but the OOC JPEGs still have heavy amounts of NR applied. The images are very soft at ISO 1600 and 3200. Oddly it seems that more NR is applied when set to "Off" than when set to "Low".
Shoot in RAW.
I remember this to be a topic of discussion going back many moons ago about the nx200 and it seemed to be a subjective debate (as noted by the above helpful response). Different firmware 'seemed' to effect the jpeg NR outcome. Sorry I cant be of much help since I rarely shoot in jpeg. Hopefully there are others more experienced in the jpeg arena to confirm your observations and make some suggestions.
Unfortunately this is a BAD issue of nx300, discussed at launch and even reported to samsung by me and other members here.
Iso 100 to 3200 have a default nr applied whatever the setting. After 3200, high iso off disabkes nr. A paradox is that I sometimes prefer shooting at 6400 than at 3200, if I need the ooc jpg.