Sigma Em-140 Macro Flash help needed

Started Jul 15, 2012 | Discussions thread
T Evergreen Forum Member • Posts: 95
Re: Sigma Em-140 Macro Flash help needed

I'd expect the flash is not compatible with the Pentax through the lens metering. Pentax uses a P-TTL system where there is a pre-flash where exposure is measured, followed the main flash. The time between the two flashes is quite short so it appears there is only one flash.

To test your P-TTL, use the built-in flash and install a Pentax kit lens or DA prime, and turn on the 2 second self timer. When you press the shutter release, you will see the pre-flash and then 2 seconds later you will see the second flash. Then you can see if this works with the Tamron mounted and then turn off the built-in flash and use the Sigma flash.

This should tell you what's causing the problem.

Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow