Macro Flash For G1

Can anyone recommend a flash unit suitable for taking macro photographs of jewellery? I use the Olympus Zuiko 35mm f3.5 macro lens with the Panasonic 4/3 - m4/3 adaptor and the results are OK for documenting things but not at all acceptable for creating images suitable for selling pieces or for applying for exhibitions. I looked at the Olympus STF-22 unit but this is SO expensive and needs a further £130 adapter to use with this lens. I would, however, just bite the bullet on that if it were the correct solution.

Any thoughts or ideas welcome.

 

Thanks for that. I am not really sure what I'm after, so it is one to consider!