Flash on crop sensors

[recon photography]

when using say a 100mm on a crop sensor should the flash be zoomed to 100 or 160? (yes i know few if any canon flashes zoom to 160 but you know what i'm asking)

 

[Loswr]

If you're using a relatively recent Canon flash (EX model) with a motorized zoom, it automatically adjusts for sensor size. But yes, if you're setting zoom manually, use 1.6 x FL for APS-C.

 

[recon photography]

If you're using a relatively recent Canon flash (EX model) with a motorized zoom, it automatically adjusts for sensor size. But yes, if you're setting zoom manually, use 1.6 x FL for APS-C.

thanks neuro <3