Image Quality Low Light Multi-Megapixel

In the MP Low Light Shootout, there was a lot of testing below 1 Lux. Although this is a great analysis of the extreme end of the "environment harshness" scale I would think many/most installation will add IR illumination if the scene ever dropped to these levels anf a usable image was required at <1 Lux conditions. When IR is on the effective level of illumination increase greatly and the results of the shootout become less useful when comparing the different sensor pixel counts (5MP, 2/3MP, 1MP).

From the images of a indoor camcorder test below (Sony flagship SR1 with 1/3" CMOS):

One can see that usability of low light (read evening/early morning/during storms) color images rapidly deteriorates below about 5-10 Lux.

Therefore, IMO, an given that IR will be used at night, and given the decreasing price gap between 1/2/3/5MP cameras, an important decision making criteria will be the performance of the camera in 5-10 Lux lighting conditions.

So the question goes: has anyone done comparisons between between 5MP vs 2/3MP vs 1MP cameras at lighting levels around 5-10 Lux where color images are still usable but have begun to deteriorate significantly? Did you find that in these situations that the 5MP unit was not much worse then 3MP and even 1MP models?

Bohan, as background, our test on How Lowering Light Levels Impacts Quality may be of interest to you.

At 5 to 10 lux, you will likely get an image even with an 'average' 5MP camera. The problem will be is that the image will typically be noisier and darker than the equivalent one at 2MP. Of course, pixel count is not the only factor. An Axis Lightfinder 5MP will likely outperform any color only 5MP camera, etc. However, as a general rule, the higher resolution camera would be noticeably worse at 5 to 10 lux. You really need to get 50 lux and above not to see any degradation.

John: thanks alot for the link - I can;t believe I missed that one!

That article is almost exactly what I wanted. Could you let me know the camera models so that I can verify that are all using 1/3"ish sensors?

To be honest the differences were not as big as I imagined. It would be really great to get a 5MP camera added to that article.