[bdery]

I'm beginning to think my sigma 530 ST DG needs to be reset to factory settings, or something like that...

At first it worked well, within the limitations of PTTL. But for a few weeks, try as I might I cannot get flash exposure to make any sense (with a K20D). If I use slow sync flash, I get a decent exposure, but otherwise, I get dark images. My theory is that the lash is not in sync with the camera anymore.

I have changed no settings on the camera. I can confirm that the built-in flash and my AF280T both work flawlessly.

Anyone have insight?

[bdery]

OK, I ran some tests.

When my Vivitar 285 HV is mounted on the camera, it fires ok (I took pictures in front of a mirror). However, the Sigma fires when it wants... totally random. Most of the time I see no light coming out of the flash on the picture. Sometimes I didn't see any flash firing with my eyes, sometimes I did.

The AF280T also fires all tie time, well timed, just like the Vivitar.

Triggered by the YN-04 II radio trigger, the Sigma fires randomly (I took pictures of the flash firing) while my Vivitar fires every time.


Any ideas?

[reeftool]

I'm no flash expert but the obvious thing to look at would be the connection between the flash and hot shoe. If 2 other flashes work and your Sigma is intermittent, then it may not be making a good contact.

[bdery]

I used the TEST button and it also works randomly, so I'm guessing the problem is internal. I will contact Sigma about this, but any additional input would be appreciated.