Nikonian72 wrote:
An interesting note about speedlights is that the manual "power" settings (1/1, 1/2, 1/4, 1/8, 1/16, etc.) concern flash duration (length), not light quantity. As an example, 1/2 power may equate to 1/500-sec flash duration, and 1/8 power may equate to 1/10,000-sec flash duration.
Got it! Thank you. And I do have one question.. If I use two Yongnuo 565EX speedlights, one on the hot shoe and one remote, to add more light for a shorter flash duration, should I use the optical slave or the radio slave to get the flashes to fire at exactly the same time, or maybe it doesn't make a difference? I can't find any information about how close the firing speed of the slave is from the main flash from the two different triggering options. Maybe they are both so close it doesn't matter.