> Since a magnitude zero star provided an illumination > of 2.5E-6 Lux, The lamp would be 5E+4 fainter , or at about > mag 12.8 If the Sun is -26.4, these figures would give 91000 lux, which is just a little short of what I think I have seen; and 32 lux for the lightbulb at one meter. But the 3W figures do not match what I read on a pack of 25 W lightbulbs - 200 lm, or 64 lux spread over 1/4 of the sphere. This would give only 8 lux for a similar 3W lamp. You could easily measure the light from your intended lamp with a photographic light meter, or an automatic camera with exposure readout, using a target filling (more than?) the field-of-view (or measuring the light-source itself) and comparing (the same target in) bright sunlight. ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www2.satellite.eu.org/seesat/seesatindex.html
This archive was generated by hypermail 2b29 : Sun Apr 29 2001 - 02:58:44 PDT