Selection Guides
1/1.8" vs 1/2.8": Choosing the Right Sensor Format for Low-Light Surveillance
Sensor format decides how much light each pixel collects. A buyer-oriented comparison using real module specs - IMX678 (1/1.8"), IMX585 (1/1.2") and the 1/2.8" class.
Why sensor format comes before resolution
When two modules carry the same megapixel count, the physical size of the sensor often explains the price gap. A larger format spreads the same pixels over more silicon, so each pixel collects more photons in the same exposure time. In night surveillance, that difference shows up directly in noise, color retention and how long the camera stays in color mode before switching to infrared.
The 2026 sensor table illustrates the spread. The 8MP IMX678 module uses a 1/1.8-inch format; the IMX585 class reaches 1/1.2 inch; and the high-volume 1/2.8-inch class covers sensors such as the IMX675, IMX415, IMX662, IMX335 and IMX577.
What the lux numbers actually mean
Minimum illumination is measured with the sensor-facing light source at a defined correlated color temperature, and the value states the darkest scene in which the module still produces a defined video level. Inside one catalogue these figures are directly comparable: the IMX678 row lists 0.001 lux, while the IMX585 class lists 0.0001 lux on the same test basis. A one-order-of-magnitude gap like that is a real format advantage, not a marketing rounding error.
Wide dynamic range behaves the same way. A 120 dB WDR rating across an AI ISP line tells you the sensor-plus-ISP pipeline can hold detail simultaneously in a lit doorway and the dark room behind it.
Matching format to the job
Entrance and perimeter cameras that must hold color at night justify the 1/1.8-inch IMX678 class. High-volume projects where infrared illumination is acceptable can stay in the 1/2.8-inch class and control cost. Scenes with headlights or gate lighting need the WDR headroom regardless of format.
Ask the vendor for the test basis behind both the lux and WDR figures, and for sample footage shot at the rated illumination rather than studio charts.
What we ship
Our AI ISP dual-board line covers both ends: the 8MP IMX678 module at 1/1.8 inch with 120 dB WDR and 0.001 lux, and 8MP/5MP options in the 1/2.8-inch class. Request the full datasheet through the contact form and we will confirm which format fits your scene before you commit.
