Sigma EF-500 DG Super and Sony A100

[somethingtohide]

So I bought the Sigma EF500 DG Super for Sony cameras yesterday, and I've been playing around with it.
Many people have problems with underexposing and overexposing, but I don't really have that sort of problem when bouncing flash (what I normally do).

But my question is, how will the wireless thing work?

What I want to happen is...
Have the flash off the camera, sitting somewhere close by.
NOT use the camera flash. The only flash I want used is the Sigma.
The Sigma automatically fire when the camera takes the picture.
I don't want to have to try and press the flash button and the camera shutter button at the same time, yaknow?

Is there anyway I can do this?
I tried using wireless mode, and setting it aside. But it's not firing, unless I pop up the camera flash.
Do I have to change some camera settings? Or what?

 

[Garbz]

Wireless probably uses an SU-4 style trigger. This means that when the flash sees a sudden burst of light lasting less than 1/1000th of a second it'll trigger too. That means you NEED your oncamera flash to fire.

There are other systems more advanced like Nikon's CLS where the flash fires before the picture is taken to sync it all up so when the shutter opens everything is fine and the internal flash did not expose the picture.

But without that system the only option really is to set the internal flash to manual and at its lowest power possible, if you can, so that it doesn't affect the picture much.

 

[somethingtohide]

Under flash settings on my camera (JUST found these haha) there's a "Wireless" Setting.

After reading both of the manuals for the camera/flash, it seems like this is what I'm looking for.

It said that the camera's built-in flash fires a teeny bit early, and is still sync'd with the flash gun and fires that one off just at the right time so that one's the only one that exposes the picture.


I tried a shot like that earlier and it seemed to work.

However I tried another shot and it seems that both flashes exposed, because there was a shadow coming from the direction of my camera. Then I covered the pop-up flash with my hand and took the picture and kinda got the result I was looking for.

It's just kinda under exposed.
I know this isn't the way to do this haha.