On Sat, Aug 1, 2009 at 11:21 AM, AlunFoto<[email protected]> wrote: > Since my Pentax AF 540-FGZ flash began acting up a couple of weeks > ago, I've been considering other flashes to replace it. Both Sigma and > Metz have alternatives sporting the same functionality and output > power. Today I gave in to the shopping lust and grabbed a Sigma EF-530 > DG Super, which was a good 500 NOK (90 USD, 50 Euro/GBP) cheaper than > the Metz. > > Well at home, I subjected the flash to some tests. Exposure looked > nice on both K20D and K-7 and P-TTL seemed to work as it should. But > alas. > > As you know P-TTL actually requires two blinks for each press of the > shutter button. One blink to meter, one to expose the shot. So the > flash needs to be sufficiently charged for two blinks before > communicating "ready" to the camera. The Sigma reports "ready" when > charge is sufficient for one blink. Which means that the camera can be > fooled into metering for flash, but receive no output from the flash > when the actual exposure takes place. > > I discovered this by taking a series of shots with the K-20D. The > first two shots were correctly exposed, but then followed three or > four completely dark frames, and at last one correctly exposed frame > with ambient light only. I waited 30 seconds to let the flash > recharge, and repeated the series while watching with the camera away > from my face. First there came two exposures with double-blinks. Then > came three exposures with one blink, and at last a long exposure > without flash. The three single-blink exposures turned out black. > > So back to the store, I did a test series right there for > demonstration. The salesperson sighed. "Worst thing is," he said, "I > don't think your flash is faulty. We've seen this on Sigma flashes in > combination with Canon as well". > > I was offered to return the flash without any cost, but chose to trade > it for a Metz 58 AF; spending the additional 500 NOK. Naturally, I > asked to test the Metz before committing the money, and this flash > behaved as expected. All P-TTL flash exposures correct. > > Lesson learned. > > Oh, and the Metz is still a good 1000 NOK cheaper than the original > Pentax AF 540-FGZ, in case you wondered... :-) > > Jostein >
The Sigma flashes have a well-earned reputation for being cheap junk. They're both cheaply built and also very rarely actually fully compatible with the flash protocol they claim to support. Metz on the other hand makes superb kit. -- M. Adam Maas http://www.mawz.ca Explorations of the City Around Us. -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
