Discussion:
How bright is 65 lumens?
(too old to reply)
r***@gmail.com
2019-12-29 01:53:46 UTC
Permalink
Ooh, impressive. "The rest of us understood the question." I feel so ashamed.
Phil Hobbs
2019-12-29 02:08:21 UTC
Permalink
Post by r***@gmail.com
On 02/03/2003 Repeating Decimal wrote: Unfortunately, there is a
big mix-up in the units you are using.
*Brightness* has a very well defined technical meaning. Most
people use
brightness rather loosely and incorrectly.
Part of the trouble is the tendency of the Radiometry and
Photometry Powers That Be to redefine common pre-existing terms,
and then scold people who don't follow their lead. "Intensity" and
"brightness" are the two most egregious examples. In the
vernacular, a 200W tungsten filament is (approximately) twice as
bright as a 100W filament, but to a photometrist they have the same
brightness since the surface>> temperature of the filaments are
about the same (the extra power goes into heating twice the area to
the same temperature).
In short, you need to learn somewhat more about photometry before
you can>>> ask a meaningful question and understand the answer.
Humpty-Dumpty at least paid words extra when he made them do extra
work. ;-) The rest of us understood the question.
Cheers,
Phil Hobbs
IBM T. J. Watson Research Center
Ooh, impressive. "The rest of us understood the question." I feel so ashamed.
Well, you're almost 17 years late for the party, after all. I expect
you were in the second grade back then, so don't feel so bad. ;)

Cheers

Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com
Loading...