Have been getting advice from local Maplin retailer and Swann techs on the problem I seem to have on a 2 year old DVR4-100 with 8 metre night vision cameras. Struggle to get any motion detection and some say its the DVR and others the Camera. Have upgraded the camera wires and replaced one of the cameras with a Swann Pro 630/35 metres night vision. When I play back any events, even the Pro camera, its like watch a scene from the Movie "FOG" just swirling mist and shapes but no definition. Am I expecting too much from this Swann system and if I want to improve it am I looking to replace the cameras, the DVR or the lot. Its getting a bit expensive so I want to make the right DIY decision Thanks