Bob: > Joseph > > Does your ambient lightmeter also have a FlashMeter? I am not currently working with one. Which one would you suggest ? Is Minolta a good brand to use or are there better ones ? I would like to work with one that would also read the color temperature and maybe even analyze the spectral power distribution to determine how the studio lights compare to natural daylight. Can you make any recommendations ? > If so do a quick empiracle test, assuming you can get access to studio > lights and possibly a studio flash of known power (Joules) output. > > Take an ambient reading with the lights on a known setting (full) > Take a flash reading with a studio flash on full at a measured > distance Since the flashes or strobes usually fire for only a fraction of a second, how can you read the measurement from the lightmeter ? Can it be set to "run" continuously and then produce a graph that would show the the variation during the time the flash was discharged ? How would this measurement be performed ? > You have enough info there to create your own conversions. > > > As Karl stated: guide-number to power depends on a lot of things, not > the least of which is reflector design. Next is understanding the > difference between quantitative measurements of "light" and those of > radiant energy. Two units could consume equal power (watts) yet > produce wildly different amount of visible LIGHT. The fraction of > energy emitted as UV/IR instead of light for instance. Reflector > design of course means that in one case the light emitted could go in > all directions, in another be in a highly focussed collimated beam. > > Bob Thank you very much Bob for your help and the helpful recommendations. Warm regards, Joseph -- Dr. Joseph Chamberlain, D.D.S. Oral and Maxillofacial Surgery
