inconsistent (maybe) second curtain sync

I wanted to do a little experimenting with 2nd curtain flash sync, so i set up a teddy bear in the sun room and did some portraits, some with 1st curtain sync and some with 2nd. I compared the results in DPP, using the "info" box to show me which photo was made with which curtain. No problems. Then I left the camera in 2nd curtain sync (intentionally) and did some shots of my wife but when I checked the results in DPP, all the shots showed to have been made with 1st curtain sync. I thought, man, that was careless, but when I checked the camera it was still set to 2nd curtain, the way I left it. So I just scratched my head and wondered what had happened.

Today I went out to do some playing with 2nd curtain sync and leaves blowing in the breeze.When I checked the shots, DPP showed all of them to have been made in 1st curtain. Like before, I check the camera and it's still set to 2nd curtain. At this point I'm sure the camera's acting up, so I just fired off 2 shots, one set to 1st curtain and the next to 2nd curtain, because I'm sure they're both going to show 1st curtain, but they didn't. The one I shot set to 1st curtain showed that way, and the one I shot set to 2nd curtain showed that way.

Has anybody heard of this?
Thanks

I can't really see why it matters, but it's a 450D (Rebel XSi) using the on-camera flash. I've also done a bunch more test shots, and DPP identified the correct curtain each time.

Your shutter speed is still within sync range?

theatrus wrote in post #14194144
Your shutter speed is still within sync range?

Yeah, actually, the camera won't allow you to raise it above 200, which is the highest sync speed for the 450D.

What camera and what flash?

With some settings (like FEC), the one made on the flash will override the one made on the camera.

2nd curtain sync only works below a certain threshold shutter speed, it differs for various camera models. Check your manual, it will say what it is for your camera. Maybe you had a shutter speed set above that threshold.

bsmotril wrote in post #14195815
2nd curtain sync only works below a certain threshold shutter speed, it differs for various camera models. Check your manual, it will say what it is for your camera. Maybe you had a shutter speed set above that threshold.

The manual only says, "slow shutter speeds" but I just ran a little test and you're right; looks like the cut-off point is 1/30 sec.
thanks a lot.