Among the reasons to select the Panasonic G1 is its small size.  It would be nice to find a small flash to complement this fine small camera.  While i am waiting for my copy to be delivered, I have been collecting data on the most common flash units that will work with this camera.

My major requirement is that the flash can be used in bounce mode, and I only surveyed units that allowed that.  It seems that many flash units will work.  It seems that the requirements are that the flash and camera communicate and that the flash allows the camera to set the flash exposure.  It may also work if the flash can set its own exposure.

Mike reports that his Canon 580 works very well with the G1.  That means that many others will work.  Below is a table showing the guide numbers and size of my Canon EX 580 II and the other two units that seem to work with the G1 with the bounce function that I require.

Flash for Panasonic DMC-G1   Guide Number   W   H, folded   D, folded
Canon 580 II      58/190      3.0   5.4   4.6
Metz 48 AF-1      48/157      71/2.79   5.4   3.89
Olympus FL-36   36/118      67/2.6   4.3   3.7

As you can see, there isn't much difference in the size of the units.  That means, to me, to pick the best specs.  If you have a Canon 580/ 580 II, it should serve you well.  If you must buy one, the Metz seems to be an obvious choice.  Its specs are materially better than the Olimpus unit in all ways as well as proce.

Good luck!
Wil