light is a premium underwater we have strobe lights to illuminate large scenes and bring back colour and contrast to subjects continue lights measured in a thousand of lumens are powerful tools for shooting video but there's one light source that often gets overlooked:a proper focus light.
Reflection
if an object does not emit is own light it must reflect light in order to be seen a beam of light incident on the metal surface is reflected reflection involes to rays an incoming or incident ray and an outgoing or reflected ray
spectrum of light
the visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye electromagnetic radiation in this range of wavelengths is called visible light or simply light A typical human eye will respond to wavelengths from about 390 to 700 nanometers