what does the term "display visual resolution in pixels/degree" means?

i know about display visual resolution in pixels,but doesn't understand the term "pixels/degree". What is degree mean here? please give answer with example if possible.

Thanks in advance.

Answer 1

[Daniel Shub]

In vision, the number of degrees of visual angle ( http://en.wikipedia.org/wiki/Visual_angle ) is generally more important then the physical size of the object (i.e., the number of pixels). As you move the monitor further away the visual angle decreases and as you move the monitor closer the visual angle increases. When the monitor is very close to you eyes, you can see the individuals pixels, when it is far away you cannot.

In order to answer your question you need the distance the monitor is from the eye r and the spacing between pixels x. With that information the number of pixels per degree y can be approximated with is

y = r*tan(pi/180)/x

where pi/180 is equivalent 1 degree.

[snake eyes]

Thanks Daniel.Now its more clear to me.

Can u tell me in case of LCD or LED what is the standard 'r' and 'x'?

Thanks again for the reply.

[Daniel Shub]

There is no standard. The native resoltuion of the LCD/LED, the size of the monitor, and the aspect ratio of the monitor affect the number of pixels per unit length (i.e inch). Luckily this can be easily measured. I think there is a ruler function that will computer the DPI, but you can measure it with a real ruler and knowledge of the native resolution. The distance you chose to sit from a monitor r, is also not standard. This requires a tape measure.