Originally posted by stewart_photo I'm not here to engage in a tit for tat debate over every issue you want to raise, Will. You've had problems. Fine. Since you're not asking for assistance and most others (including myself) have not had those issues, there was no need for me to comment about that. What I'm addressing is the other brands are superior impression you've created by saying "I get too many photos with people whose eyes are drooping that Nikon and Canon photographers don't get," and "I have had problems -- mechanical problems, exposure problems, problems with subject's blinking -- that my Nikon using friends tell me are not common with the best flash units available for their systems," and more.
I'll state once again that, compared to other manufacturers, I don't feel Pentax is any more prone to problems or issues, and certainly don't feel Pentax is inferior. You obviously disagree, put more weight on what your Nikon and Canon friends say, and are setting a standard Pentax cannot possibly achieve in every regard ("Pentax doesn't need to be as good as Nikon or Canon, it needs to be better."), so I'll simply leave it at that.
stewart
I cannot comment on failures rates of various flashes, but the P-TTL "blinkie" issue is a real one. You might ask yourself why Canon and Nikon are both offering second generation pre-flash systems? The answer is that the original systems both suffered from the same sorts of problems that plague the P-TTL system, especially "blinkies", but also inconsistent flash metering. Just search for Blinkies and Nikon or Canon and you will find plenty of (older) discussion about the problems.
That being said, the "blinkie" issue is likely a shortcoming of the camera, not the flash. The Pentax cameras to date are simply not fast enough to allow a shorter delay between pre-flash and main flash, so some people get caught mid-blink. My son and granddaughter do this very consistently, and I have encountered others that do so as well. It is the camera that tells the flash to pre-flash and then to fire the main flash, so the speed of the mirror assembly, shutter and also the metering system determine exactly when the two flashes take place (and therefore control the delay between the two, which is the rootcause of the "blinkie" problem), and the Pentax design is simply not faster than some people's blink response.
The flash metering is also a PITA as it can appear to be acting in unpredictable ways when it "sees" bright reflections in parts of the scene, among other issues.
I get much more predictable results using auto flashes, but you give up auto-zooming heads, auto iso and aperture setting and the very useful high speed sync. Using red-eye solves the "blinkie" problem in most cases, but it creates other problems at the same time.
I guess I would have to agree that P-TTL is not very useful and is also something I cannot count on in critical situations.
Ray