Go into the menu and Turn on Anti-Fog. It sounds like some sort of demister but actually it's to stop reflections from microscopic water droplets in the air (fog/mist).
Sweet! Thank you, will set that when I get home.
Synology don't seem to be responding to my requests about the 3 unsupported camera's but they are working perfectly fine at the moment being set as a 'generic dahua camera' in surveillance station.