Another term....................
Quote:
Originally Posted by
FVCCHRIS
That's where the term G-15(and others) is derived from. It allows 15% of the visible light to penetrate the lens and reach the eye.
There is also another term that is used in Europe and most other countries which is absorbtion. This means , the lens absorbs a certain percentage, it is actually the reverse of the transmission.
If a lens absorbs 50% of visible light it would also transmit 50%. For the sale of sunglasses it is believed in Europe that a consumer understands the term of a certain percentage better than the term transmission.
Spectrometers can be set to give a reading in either way you prefer.
I also belive that the word G-15 is an old trademark of B&L like the TrueColor by AOCO and stands for their greyish green lens. You can tint that color to 30 - 50 - 75 percent or whatever transmission or absorbtion wanted.