At 10:05 AM 12/07/05 +1000, you wrote: > Thanks for that Bernard, & the visibility, before fitting it to >the ASW 28. That way I can return it in good condition and without >drilling holes, if the light isn't outstanding in bright daylight. >Does anyone in this forum know what work has been done with battery >operated strobes in front of a focusing reflector to provide best strobe >light in a defined direction? Best regards Geoff
Geoff, I guess you could run some experiments with photo flash accessories to try the strobe/reflector thing. Lights, particularly focussed forward strobes will help the head on case(how narrow do you make the focus - the Ventus/Skylark 4 collision was at 30deg from head on) but of course don't solve the mutual blind spot problem and for those who believe we don't have a problem a friend of mine who is an current Australian contest pilot has been to 3 contests where pilots have died in mid airs and two more where mid airs occurred. Mike ________ Also Adrian Jansen sent me this that he found the other day: Mike, Came across this for more than you ever wanted to know about photometry of flashlights and visibility. Seems like its still an ongoing subject for research. http://cie2.nist.gov/meetings/1999_Warsaw/Workshop_Proceeding4.htm Also some figures for light efficiency, all in lumens/watt: Tungsten incandescent 12-20 Tungsten-halogen 18-25 Hi-efficiency fluorescent 45-60 White LED 25-60 ( best lab samples ~ 100 ) xenon HID arc ( continous ) 30-150 ideal white light 242 ( all energy converted to light ) ideal monochromatic 556 nm source 680 ( max eye sensitivity ) Xenon flash tubes are around 150, but because the flash is very short ~ 1 msec, you can get very high peak intensities, not achievable by any other source. I havent found a number for the background intensity of the sky, or a way of relating that to any of the above. Borgelt Instruments - manufacturers of quality soaring instruments phone Int'l + 61 746 355784 fax Int'l + 61 746 358796 cellphone Int'l + 61 428 355784 Int'l + 61 429 355784 email: [EMAIL PROTECTED] website: www.borgeltinstruments.com _______________________________________________ Aus-soaring mailing list [email protected] To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
