Wow, that looks like a Dahua 2381:
https://www.dahuasecurity.com/products/productDetail/21537
This is my take on sensor size. Sensor size affects the pixel size, and pixel size plays an important role in how well a camera does in low light. The bigger the size of each pixel on the image sensor, the more light that makes it down to the sensor, ... the more light the sensor can capture in every pixel, the better the low-light image quality.
Most folks here would agree that the best low-light image quality (for the price) has been in the cameras that use the 2MP 1/2.8" sensor. This is the sensor is found in the super popular Dahua Starlight models, along with some of Hikvision's Dark Fighter models.
For cameras with more megapixels, the pixel sizes are usually smaller. The physical size of the sensor doesn't increase equally to the number of pixels added. Smaller pixels means less light collected. Until recently, for 8MP cameras the best (again, reasonably affordable) image sensor was 1/2.5". That sensor is 12% bigger than the 2MP 1/2.8" sensor, but it's handling 400% more pixels. Much smaller pixel size. IMO, low-light images from the 8MP 1/2.5" sensor are usually pretty horrible compared to the 2MP 1/2.8" sensor.
The 8MP 1/1.8" sensor you found is the latest. It does better in low-light than the 8MP 1/2.5" sensor does, but IMO it's still a bit off from the 2MP 1/2.8" sensors.
There are a few companies that resell Dahua equipment under their own brand, like Lorex and Amcrest. They don't usually get Dahua's latest camera models like ones with the 8MP 1/1.8" sensor (or the ones with the 2MP 1/2.8" sensor). I don't know much about Montavue... I'm surprised to see they are selling Dahua's latest 4K camera models. It also looks like they are not disabling the IVS feature in the firmware (advanced motion detection, if you're not running
Blue Iris for your NVR, you definitely want IVS)...
Most folks here get their Dahua equipment from a great vendor named Andy (
@EMPIRETECANDY). He sells them under his EmpireTech brand and he's been able to get pretty much any of the models for us... models that Lorex, Amcrest, and even Dahua's US branch don't offer.
