Some calculations for throw and usable throw, even on certain brightness modes etc.

techwg

Flashlight Enthusiast
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May 4, 2007
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I added these to my PD35 review thread but I figured I would make a thread just with these in case other people are interested in this. I have tweaked the calculations to simplify them while getting the identical results. As long as the standards for the calculation of throw are not altered from the standard 0.25 lux value this will work perfectly.

To calculate rated throw from the intensity (cd) rating:
Type the cd intensity into calculator and hit the sqare root button that looks like a check mark or tick. Then multiply by 2 to get the official throw or ignore this step for the "usable" (50%) throw distance.

To calculate the aproximate intensity (CD) rating by just a rounded throw value written on your flashlight box:
Type the distance in and multiply it by its self and divide that resulting number by 4. The value will not be 100% accurate because the box of your light only shows you a rounded figure, else they would need to say "With a 185.4723699099140750503283214798 meter throw!" which would not fit on the box (this is the rated throw of the PD35)

To calculate the throw of a given mode of the flashlight:
Type in the number of lumens of the mode you want to check, then divide it by the total amount of lumens the light is capable of producing on full power mode. Hit M+ (memory +) on this value and multiply it by the intensity (CD) rating. Once this is done, press the square root button to get the "usable" throw at that distance, or for the official throw just multiply this value by 2.
 
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