problem w/550EX flash on D30

philgabe:

Today, I brought my camera and flash down to the Canon Service Centre here in Singapore to check with their service rep on this problem. They were very helpful and spent quite a lot of time with me on this. They said that this was the first time any users of D30s/D60s here had complained to them about this problem.

Then they tested their own D60 and 550EX in front of me. And what do you know.... they got the same results too - the exposure with the built-in flash was OK but the 550EX consistently under-exposed by 1 stop or more. They were quite surprised with the results and promised to carry out more tests in their lab and would get back to me by next week on their findings.

Also, they confirmed that the recent firmware upgrade to 1.0.2 was not meant to address this problem and would have no effect whatsoever on flash exposures.

Meanwhile, their recommended solution would be to use the flash exposure compensation to correct for the under-exposure. Alternatively, they could reprogram my flash for me so that it would output a higher flash level to achieve the same correction.

PSChia:

Can you ask them how this is possible? Is it because of the calibration of the flash then? It sounds so weird because the FEL reading is taking after then shutter is depressed but before the mirror flips back up. So you would think that the reading is the amount of light necessary regardless of the calibration of the flash.
Don't think that I don't believe what you're saying, I'm just trying to understand how it's possible.

Phil

When shooting with the 550ex it's also possible to get an "averaged" E-TTL flash meter reading by switching the lens to manual focus mode before taking the shot.