Hi guys, sorry about the topic being a bit non-descript, however I like making it easier for others to search/find in google should they have a similar question. Basically, I have an Olympus E-420 and an old Sigma EF-500 (with pentax compatitble hotshoe mount, as I also have a Pentax *ist D). I'm thinking of hooking up the EF-500 to the olympus. Now, i'm not so worried about voltages anymore (I've asked that previously, my olympus likes a voltage of 3 - 6v and the flash is 5.9v and has been slated as compatible. What I would like to know is, with the pentax hotshoe mount on the Ef-500, will it sync up with my olympus? I understand I won't have TTL metering and such, that essentially my camera will be on manual and my flash on manual. However, when I press the shutter will the flash fire? Any help would be greatly appreciated, thanks heaps.