Without itself emitting light during the exposure?


1 Answer 1


The D800 doesn't have a radio trigger, so yes, it emits light when talking to other flashes -- whether with a dumb optically-triggered slave or with the CLS (Creative Lighting System). The light emitted is minimal, but it's there.

  • \$\begingroup\$ But, it has a "commander" mode where the emitted light is minimal and intended of communication only, not to contribute to the exposure, right? \$\endgroup\$
    – mattdm
    Nov 26, 2012 at 20:05
  • \$\begingroup\$ I think (perhaps mistakingly) that the pre-flashes used for TTL metering happen before the shutter curtain opens. I guess this is basicaly the question \$\endgroup\$
    – strobity
    Nov 26, 2012 at 20:11
  • \$\begingroup\$ Yes, the light emitted during preflash is minimal, but it's certainly there: try shooting a highly reflective surface at 1/250 sec/small aperture and you'll have no trouble capturing the preflash emitted in commander mode. \$\endgroup\$ Nov 26, 2012 at 20:43
  • \$\begingroup\$ The command pulse is actually distinct from the preflash; that's what you are capturing in that case. The preflash does happen before the shutter opens, but the control flash can't. But the important thing here is that the commander mode uses a diminished pulse for the control, and while it will show up in reflections, it's intended to be minimal and not contribute to the exposure, as opposed to "master" mode, where the pop-up flash also fires intentionally to light the subject. \$\endgroup\$
    – mattdm
    Nov 26, 2012 at 20:48
  • 1
    \$\begingroup\$ If distance (or complicated reflection paths) is not an issue, there is the SG-3IR infrared filter for the pop-up. It's intended use is with the R1 twin-tube macro flash, but it will work with the whole CLS, making the pop-up into a sort of reduced-power SU-800 unit on- or near-axis (with some white light spill, of course). \$\endgroup\$
    – user2719
    Nov 26, 2012 at 21:56

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