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Old Jun 8, 2009, 10:15 PM   #1
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Default Pentax 360 flash

the 360 flash has a guide # 36, if i use 2 of them to light up a subject, with one on the k20 and the other wireless, would i still be lighting up my subject with a guide # 36 or now 72

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Old Jun 9, 2009, 2:38 AM   #2
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The guide number represents a constant so you can calculate what exposure you need to light a subject a certain distance away from the flash.

Combining two flashes beside each other will give a different guide number, and because you are use the guide nr to calculate an f stop value i guess (not completely sure) that it will double the guide number.

Putting one flash closer to the subject makes the guide number useless, you would have to calculate any position in the area lighted to get the gn for that position. Looks like a fun calculation

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