Dfox973

Evening all, Looking for a bit of advice. I swapped one of my cameras out for a Hik vision colorvu camera. I have been having issues with grainy images. I have swapped the pre made cable out for cat6 cable with baluns at either end to the DVR and then gave the camera it's own 12V DC power supply which has made it better but do I was wondering should my images be better than this at night? They seem grainy and noisy I'll upload the pictures but they are too large in file size at the min Thanks