light is traveling at 186,000mps, bouncing of everything you focus on a plant 50 ft. away behind it another plant less than 2 ft. you have to refocus to see this plant ! why? light lag is so small .
science behind focus of light
Started by isenor, 06/20/2010 01:44PM
Posted 06/20/2010 01:44PM
Opening Post
Posted 06/20/2010 02:06PM
#1
When an object is infinitely far away - virtually anything in the night sky qualifies - the light rays can be pictured as parallel. When an object it close, the light rays coming from it are diverging, and the focal plane moves farther away from the lens or mirror. The closer the object is to the telescope, the more the incoming light rays diverge, and the farther back the focal plane moves.
It's easier to envision if you think of a point source of light moving closer to the telescope.
Clear skies, Alan
It's easier to envision if you think of a point source of light moving closer to the telescope.
Clear skies, Alan
Posted 06/20/2010 03:33PM
#3
thomas zukouski said:
light is traveling at 186,000mps, bouncing of everything you focus on a plant 50 ft. away behind it another plant less than 2 ft. you have to refocus to see this plant ! why? light lag is so small .
Yes, the time lag is small, but so is the wavelength. 8)
Jim McSheehy
Funding Member
