Day and night performance of megapixel cameras are covered by Gordon Smith, Managing Director of GVD.
When it comes to megapixel cameras and IP Video surveillance a lot of security installers have a big question mark over night time performance. To understand how megapixel cameras work well at night time it’s probably useful to understand the two main differences between analogue cameras and megapixel cameras in terms of picture quality. The best standard analogue camera is capable of 4CIF resolution which in pixels is 405,504 pixels. An entry level megapixel camera contains 1,310,720 pixels – over three times the number of pixels of the 4CIF camera. This means that with more pixels you can cover a larger area – over three times the area. And with more pixels in the picture you can zoom in much further in on the point of interest before it pixellates. A pixel is the digital standard for measuring picture resolution.
We carried out the ultimate test on megapixel cameras to test them for number plate recognition at both day time and night time. In the pictures below, we have a 3 Megapixel IQeye Sentinel camera mounted on the apex of a garage about 35m from the point of interest at the gate. As you can see the car is captured in the image at the gate, at distance we cannot read the registration plate. However, when we digitally zoom in on the car using Milestone VMS software we can clearly see the registration plate – note there is no blurriness or pixellation of the image.
Similarly, we carried out a night time test using the same 3 Megapixel IQeye Sentinel camera. The footage is taken in a rural area where there is no street lighting or ambient lighting whatsoever. We placed a small IR illuminator underneath the camera. As you can see from the picture below, even with the full headlights on, the registration plate is perfectly readable when we zoom in on the footage.
Security installers often use two separate cameras when looking for registration plates and for general surveillance at a gate entrance. As you can see with megapixel the great advantage is that you can cover the general area and registration as well as the superior image quality all one camera.