Or just a less-than-great camera. Had the same results when I did a system expansion for a customer. The DVR card had to be ordered from a distributor that I never dealt with before so I tried their cameras as well (made in Singapore, great specs -big oops). Same picture quality as what is shown in the image. Swapped two of the 3 cameras with my normal equipment and all of a sudden the image quality was great. A moderately expensive mistake.
Then who sells good cameras? I will try one as a test.