Testing Smoked vs Clear Domes
The best way to conceal where a camera is pointed is to use a smoked dome. Here's an example of a clear vs a smoked dome:
However, smoked domes pass less light and can reduce low light performance.
We tested two models of the same camera, one with a vendor provided clear dome and the other with a vendor provided smoke dome.
In full light, there is a negligible difference in image quality, but in low light, heavier artificating and reduced details were common, especially under 1 lux.
In dark scenes, < ~1 lux, smoked domes reduce image quality. Below, see the side by side comparison of two cameras, one with a clear dome and the other a smoked dome:
Notice the large increase in artifacting in the smoked dome image, making it difficult to read line 1 of our test chart or see any facial features of our test subject. Artifacting typically is a result of increased gain levels triggered by less light reaching the imager.
In low light scenes of ~2 lux, inferior low light cameras such as the Axis M3004 and M3005 are weakened with the use of a smoked dome. It is difficult to distinguish details between the M3004 and M3005 with a clear dome, but with a smoked dome, our subject is almost engulfed in artifacts and noise, and we cannot make out any character or line of our test chart.
The smoked dome on the P3354 shows increased artifacting, causing slight discoloration, but given how well the P3354 handles low light scenes, the impact the smoked dome has is minimal.
In full light, image quality is similar. Marginal coloration can be seen due to the tint of the smoked domes, but nothing is obscured or skewed between clear and smoked domes.
Smoked bubbles are as an accessory whose availability varies by camera manufacturers. Ensure that the bubble you select is compatible with your dome camera as variations in dimensions are common. Smoked bubble pricing varies between $6 - $70 USD Online depending on the camera and manufacturer.
If concealing the aim of one's camera is key and the scene has sufficient lighting, a smoked dome will work well. Typically, though it will come with a modest cost premium that should be considered.