This post will focus on a brief comparison of High Resolution and Megapixel cameras.  It may be known that Megapixel is better than High Res., but what is the real difference and what are the benefits of Megapixel.  For this comparison we will examine a few images captured using a Megapixel and a High Resolution camera covering the same area.  The main object of interest will be a license plate hanging on the door.

The images produced by these cameras were captured using an NVR at different resolutions.  The High Resolution images are VGA (640 x 480) and the Megapixel images are SXGA (1024 x 768).  Those numbers themselves indicate that the Megapixel camera captures more detail.  This becomes evident by comparing Image 1 and Image 2 below.

Image 1: High Resolution Camera

Image 2: Megapixel Camera

Image 1 captures a good general surveillance shot.  We can see everything quite well except for the details.  This is illustrated by the magnified image of the license plate characters in the bottom right corner.  They are pixelated and unreadable.  Image 2 shows the same scene being captured using a Megapixel camera.  It is quite visible that there is a lot more detail in this image.  The magnified license plate in the bottom right corner clearly displays the characters.  This means that forensic details can be captured using Megapixel cameras.

The above comparison showed that forensic details can be captured using megapixel cameras, but High Resolution cameras can also accomplish the same thing.  This can be seen in Image 3 below which shows the same license plate but this time the characters are actually readable.  This however came with a sacrifice because a longer focal length had to be used.  By using a longer focal length we lost a large area of the previously captured shot in Image 2.

Image 3: High Resolution 8mm

Hopefully this post illustrated the differences between High Resolution and Megapixel cameras.  High Resolution is good for general surveillance while Megapixel can deliver forensic detail and provide greater coverage at the same time.