How do I judge image quality from a sample unit?
Image quality cannot be judged from a demo clip or a specification sheet. These five on-site tests settle it in half an hour.
- Daytime detail: place readable text or a chart at the working distance and review edge sharpness and distant detail on playback. Watch for white haloing from over-sharpening.
- Backlight: aim at a window or entrance and check whether faces go black and the background blows out. This is where WDR models separate most clearly.
- Night performance: test after dark. Look at effective range, noise control, evenness of illumination and any smear.
- Moving subjects: have a person or vehicle pass at real speed and check for smear, tearing or blocking. This directly determines whether the footage is usable as evidence.
- Colour and distortion: check white balance drift, whether skin tones look natural, and whether wide-angle edges stretch visibly.
One extra tip: review the footage on the recorder and client you will actually deploy. Image quality depends heavily on encoding settings and the decoding end, so judging from the camera alone is easily misleading.
