27#sarahze
回顧selfbuilt對SR90的評測：http://www.candlepowerforums.com/vb/showthread.php?272521，已解釋了他如何量度SR90的1米照度和原因：
"Throw values are the square-root of lux measurements taken at 5 meters from the lens, using a light meter, and then extrapolated back to estimate values for 1 meter. This is my standard way to present throw on these types of high-output lights, as the beams don't really have a chance to fully converge until typically several meters out"
"note that I measured at 5m to allow the beam to converge, and then worked back for the 1m estimate"
意思是用照度計量度5米的lux值，再計算1米照度，原因是像SR90這種高光電筒，太短距離光束無法聚焦。
那麼如何由5米照度算出1米照度呢？CPF上有人解釋過：http://www.candlepowerforums.com/vb/showthread.php?325294
那就是lux值和距離的平方成反比，即是1米照度是5米照度的25倍，1米照度是2米照度的4倍。
拿Light-Reviews.com的貼http://archive.light-reviews.com/forum/viewtopic.php?f=7&t=843來説吧，裡面提到重新量度後2米照度是26,400lux，那1米照度是它的4倍，所以是105,600lux。
