sLave optically?

[Henry Low]

Hi there, i was reading about the slave optically function of the Sigma 500SUPer DG

how does that work exactly?

Thanks,
Henry

[Illegally_Alive]

It has a sensor which triggers the flash when it "sees" another flash.

[scottbergerphoto]

Optical Slaves sense the light pulse from another flash and fire the flash they are attached to. The firing is so quick that the camera doesn't notice any delay. This is not compatible with ETTL. If you are going to use this function, the flashes must be in Manual or Auto Thyristor. The pre flash from ETTL will set off the optical slave.
Scott

[Henry Low]

ahh icic, thanks for the quick replies. :D