Red Light and Alternate Dark-Adapted Illumination Spectra

You probably have already heard that red light is better for being dark-adapted. This is partially true, but also misleading unless you understand the whole story. You can use red LED and get and become dark adapted because the red light from typical 620-630nm LEDs is only minimally sensed by your eye's rods, so there is a low risk of them being over exposed and being turned off.

 

Only your long wavelength cones see the red light, so you only have limited vision up close. Also, 90% all the red light from a red LED is concentrated in a narrow wavelength range that covers less than a third of the visible red spectrum, further limiting your ability to discern most detail.

 

What you see in photopic mesopic, scotopi,    GJ filtered Photos

 

Mesopic vision is where your eyes Rods and cones work together........

 

See and differential colors   -  See long distances  -  Use minimal power

 

Mesopic Vision can be achieved even USING a sunlight spectra with great results IF the radiant flux is kept low and the light is carefully not directed at your eyes or reflected from objects close up.   However, not overexposing your eye's rods can be difficult with such a spectrum

 

 

Cyradiance advantage                     how to use and why

 

ActiveRed filter                                   how to use and why

 

Putting it all together

 

 

Tracking example crushed leaves?

 

 

MORE..........