When modeling a phenomenon, understand the phenomenon you’re modeling and your goal in modeling it, then choose a rich-enough abstraction, and then choose adequate representations to capture your abstraction within the bounds of your resources. Once this is done, test to verify that your abstraction was appropriate. Consider the impact of the human visual system on your problem and its models.

Arrival Rate

• 100W incandescent bulb 10 12 photons / cm2/s
• Sunlight 1015 photons / cm2/s
• Night Bulb 1016 photons / cm2/s

Human Eye

• Angular Resolution: 300 mm/1km or 0.3mm/1m
• the eye is very sensitive to motion, so two adjacent pixels in a gray region that alternately flash white may give an illusion of motion that’s easily detectable, which might be useful for attracting the user’s attention.