stayfix

hi, i'm wondering if someone can help. i been stuck for a while on a problem. i've replaced the cctv cameras at home with HD cameras. total 4 cameras. 2 at the back and 2 at the front. the front ones work perfect. but the back is VERY distorted. [ http://i.imgur.com/5fr2x46.jpg, http://i.imgur.com/afGzx6e.jpg ] the front are 3 meters from PSU and DVR. and the back ones are 15-18 mtrs away [running cable length]. cable used is an RG-59. power supply is a 12V 3 amp. old ones worked fine at the back, but new ones do not. old ones were the cheap basic type cameras. i've checked all connections. i've reset DVR, i've re-crimped the connectors on the cables. i do not think its the camera, and the cable. as the cameras were tested before they came to me, and the cable is fine as the old camera's worked fine. i've taken all the other cameras of PSU and just put the one back one, still no difference. this is the PSU: http://i.imgur.com/KETNwaV.jpg there are no other cables running along the CCTV cables. camera spec: http://www.everfocusonline.co.uk/HD-SDI-CCTV/Cameras/HDCCTV-Bullet-Camera any help is much appreciated.

i've swapped the camera's around and i still had bad image. i've tried both cables. still same situation. could it be a power supply issue? as its only a 3Amp. and because the cable is long, the camera isn't getting enough power. camera's are 5 amp