When Joe McNally speaks, I listen. I like his style, and he knows his … stuff. (Hi Mom!)
When he wrote about figuring out high-speed sync, I was intrigued. It’s something I’ve tried to get my camera/flash to do before, but at 1/400th and higher the shutter mirror partially blocks the sensor, creating a black border on one side. Besides that, my AlienBees CyberSync remote triggers only sync up to 1/250th anyway, so I’m pretty much out of luck here. Right?
I followed his link, but this time I noticed the part about this only works with TTL. OK, remote triggers are out. What about that flash cable I’ve got?
Set the D300 to “Auto FP High-Speed Sync”, set the flash in TTL mode, and start at 1/250th. Fine. 1/320th – fine. 1/400th – fine. 1/500th – fine (no black lines yet). etc. etc. etc. 1/2000th – fine.
Hmmm. (scratching my head) Well, what do you know? It works!
What about CLS? It works too! The only difference is the reduced output when using CLS. I had to go up 3 stops on the flash power in CLS mode @ 1/2000th to get the same brightness I had at 1/250th.
I know I tried CLS before, not sure why I thought it didn’t work. The CyberSync remote triggers won’t go that high, but I can use an ND filter to knock the light down 2 or 3 stops.