Sync Query With Sigma

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Snake Man

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Name
Andy
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I have the Sigma 500 super flash gun which I've been using off camera to good effect (I think). But I cannot get it to sync on full power 1/1 but can on any lower setting 1/2 etc.

I've been popping it via the built in flash. I have the built in flash set to -3.0 so it has no effect on the image and have been fixing the value through the FV button so the Sigma won't be triggered via the pre flash but it still won't work on full power. I'm stuck. Help please.


Cheers.
 
To be honest I don't really know the answer. I reckon it could be something very simple as changing the batterys?

I remembered when I was trying to trigger my flash with the built in camera flash I would use the pre flash and then trigger it before I was just using the flash and it was the same problem as you that it wasn't in sync. I'll have a play around with my camera and flash to see if I can get anything, I also remember messing around with a custom function :thinking:

What type of camera have you got?
 
I have the Nikon D80. I've tried new batteries, still no joy. Just a little puzzled why it works on 1/2 1/4 etc but not on 1/1.
 
The answer is simple.

The popup flash on your camera is firing a TTL preflash to calculate the exposure needed.

On some cameras (eg Nikon) it's possible to turn off the preflash and use it in manual mode. Canon EOS cameras however, don't have this function (so if you're using a canon, the only answer is to get either a wired solution or a radio trigger from ebay).

Basically, the Sigma flash is firing twice. At 1/2 power or below, it can do two flashes in very quick succession (when you charge up a flash, a capacitor is charged up, when you fire it, part or all of that charge is released). At full power, it is out of charge, and the recycle time is too long to recycle and then flash in the milliseconds between the two flashes.

So basically, it is firing, but it is firing at the first flash rather than the second.

Edit: Ally got it (I read the first sentence and skipped to the end like an excited primary school with their hand up because they knew the answer :D (sorry Ally))

I see in your profile you have a D80. I believe that you can disable the i-TTL preflash on those. Check the manual or ask nicely here and someone might be able to help you :D

Good luck!
 
Thanks for the reply. I've turned off the TTL and it makes no difference. I've also tried the SB800 on camera set to full manual and still the Sigma doesn't match up when using full power?

It's not the biggest problem in the world as I've never used full power when using the flash manually but it's bugging me now and it's always good to know how things work, or this case why they don't.
 
Now it's sounding odd. Is there any flash on full power when you try and trigger it (take a photo and watch the flash head - wear sunglasses!), or is it just not triggered by anything. If it isn't triggered by anything, it sounds like it's not charging fully before flashing (does the red light come on?)

Try changing the batteries?
 
It is being triggered, just not matching up. I've tried new batteries and when I press the test button it certainly seems full power.
 
have you tried hotshoeing it to the camera and see if it fires full power? no idea if this will mean anything, but will show if the full flash will work
 
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