Olympus e620 Flash speed

[Carter64]

I've was having a play with my e620. I stuck an OM-fit Vivitar zoom on it and an old Miranda 930TCD flash. I flicked the camera into manual and didn't check the shutter speed. I was playing, it wasn't important.
Now, the specs say flash sync is 180. Even the e30 can only do 250. I'd left the camera on 320. The pic came out just fine. I have no idea how or indeed, why! I played a bit more and found that anything above 320, the expected out-of-sync bar started to appear on the pic. Here's an example at 320:

I've naturally re-sized and also upped the contrast a little. Any thoughts/explanation? If it's consistent, I'll be well happy

 

[HoppyUK]

Seems unlikely doesn't it. Suspect high ambient is concealing what's going on.

Shoot a plain wall at a highish f/number and low ambient so that the bar appears completely black. Keep rasing the shutter speed until the bar just starts to show. You will probably get a little above the market x-sync max, but not that much.

 

[AJQS]

T lest you have the option of finding out, Panasonic lock the flash speeds as soon as anything touches the hotshoe. 1/160 :thumbsdown:

 

[Carter64]

OK, done the low ambient test. The meter suggested 1sec at f4. Pretty low
Plain interior wall.

f4 1/400

F4 1/320

f4 1/160

 

[HoppyUK]

Looks like you've got 1/320sec then If that's not max flash power, it might be marginal - the flash duration and type of flash (eg studio head) can impact on it when you're on the limit. I guess that's why Olympus are playing safe.

There is also a fractional change in brightness there. Nothing serious and it could be something else but if that was at full power you'll be cutting the tail of the pulse at the higher speeds which would explain it.