Ever since high speed sync was introduced to speedlights, I’ve seen questions about metering it. Up until now, it’s pretty much been impossible to judge with a handheld meter. You basically have to just go off your histogram. Now, that’s all changed. Originally announced at Photokina in September, Sekonic’s L-858D light meter is now getting into peoples hands.
Being able to meter high speed sync should start to put an end to the debates over just how much power is lost once you go past your sync speed. It should also make repeatability and consistency much easier. When you’re on location and fighting the sun, you’re often changing shutter speed regularly. While this doesn’t have any effect on flash below sync speed, it does when you get into HSS territory.