There is quite a bit of data online for external flash/speedlight durations, but I've never seen any data for the built-in flash. Has anyone ever tried measuring the duration of a pop-up flash at different power settings? I'm especially interested in Canon DSLRs.

  • \$\begingroup\$ I don't know, but it will be "normally fast", like other speedlights. Even the cheapest disposable film cameras have their little flash units salvaged by high school students using them to stop fast motion of water drop splashes, etc. All speedlights are even considerably faster when used at less than their maximum power level. \$\endgroup\$
    – WayneF
    Commented May 20, 2016 at 19:33
  • 1
    \$\begingroup\$ Thanks, I realize that it will be "fast", but I'm looking for a more concrete answer than that. :) I can set the exposure compensation on my camera to "turn the flash down" in order to get a faster speed. \$\endgroup\$
    – ezmopho
    Commented May 20, 2016 at 19:43
  • \$\begingroup\$ I'm guessing that almost anyone who cares about precise flash duration is not going to be using a popup flash. Since that means there's little, if any, demand for the information I'd be surprised if it is readily available \$\endgroup\$
    – Michael C
    Commented May 21, 2016 at 6:10
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    \$\begingroup\$ Why do you need this information? Just being curious or are you trying to achieve something in particular? \$\endgroup\$ Commented Sep 24, 2016 at 8:33
  • \$\begingroup\$ Mostly just curious.... \$\endgroup\$
    – ezmopho
    Commented Sep 26, 2016 at 17:54

1 Answer 1


Keep in mind that the flash duration varies according to the flash power, and it is not easy to directly control flash power for a built-in flash. Usually, at lowest power, the flash duration will be shortest, while at highest power, it will be longest. However, some studio strobes reverse this, with shorter flash duration at higher power than at partial power. (See Flash Duration of Speedlights: How long is the pop of a flash?)

I haven't found measurements of flash duration for built-in flashes, only small flash units. Actual Measured Flash Durations of Small Speedlight Strobes. This does however show the clear relationship of flash power to flash duration, and some typical flash durations for small flash units.


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