On 3/7/2017 3:42 PM, Sepp Ruf wrote:
lou.holtman wrote:
On Tuesday, March 7, 2017 at 5:11:29 AM UTC+1, Frank Krygowski wrote:

http://peterwhitecycles.com/images/p...lux-II-800.jpg

Still too much chroma, but a more realistic looking comparison than the
aperiodical illumination of Mr. White's rustic driveway:
http://baslerbikes.de/index.php/baslerbikes-2-Scheinwerfervergleich-2013-november.html

That is the headlight I use and it looks exactly the same on a pitch dark street.

Must be an extra-bright asphalt mix they use in NL - or simply a layer of sand.

I've noticed that the asphalt does lighten in color somewhat as it ages.
And I've noticed that dark road surfaces are not as visible in the
headlight beam. This is true even with car headlight beams; the dark
surface obviously reflects less light back to the operator's eyes.
(That's probably covered in the definition of "dark.")

This adds to the complexity of producing realistic screen shots of
headlight beams. And it's already complex enough, because different
camera exposure settings, different focal lengths, different lighting
environments, etc. make one website's beam shots look quite different
from another. Even if all testers used the same parameters, it might
not match what the human eye perceives.

If one were to develop an ASTM standard for headlight screen shots, all
those and other factors would have to be uniformly controlled.

Sounds like a good project for someone's masters' thesis.


--
- Frank Krygowski