Originally posted by Hey Elwood The flash I have is called a promaster 7500dx digitalFlash. It's an off brand flash gun since I can't afford the big guns like Metz, Sigma or Pentax just yet. I actually contacted Pentax directly and after some trial and error we determined that a digital flash gun will only extend to 58 mm. Anything above that the flashgun and camera don't communicate since the flash thinks a film camera is being used.
This isn't true in general; it works with the Sigma and Metz flashes. It may, however, be a problem with your particular unit — on Promaster's web site, they list the 7500EDF as compatible with the K20D and K10D, but
not the 7500DX.
Quote: I do have to say Pentax's customer service is awesome. Their people were very easy to communicate with and they really listened to your problems and frustrations and take your concerns to heart.
They have decent customer service, but sometimes you have to ask "are you
sure? Could you double check that?" and sometimes the answer comes back differently.
When I had questions about 3rd-party flashes, they flat-out refused to answer them (even when the question was more about the K10D rather than really about the specific flash). If they did give you an answer, it's going to be from a Pentax perspective, and since 58mm is the actual limit of all of their flashes, that may be why you got the answer you did.
My suspicion is that either they're just speculating about how it might work, or else they're giving a garbled response about the APS-C/full-frame conversion.
Or that they're right and the 7500DX really does have a communication problem.
Have you tried contacting Promaster? Their
flash tech support is actually quite good — I've found they're better at responding to e-mail than Pentax, even.