Canon/Quantum combo

Hello to all...

I am new to this forum and thought I'd ask others out there how they managed an issue they may have had with the Canon 1Ds and the Quantum TD5 flash system. When shooting people outdoors using the Quantum flash, I need to reduce flash output, just enough to put some catch light in the subject's eye. When reduce output to minus one stop, the Quantum changes the output to plus the same amount reduced. In other words, it's as if it had a mind of it's own, hence blown out highlights. Anyone out there have this problem with the QTD5, and how did you fix the problem??

-Michael

Do you mean background over exposed highlights? Or foreground subject blow outs?

What Q Mode are you running it in when that occurs? If its in Q-TTL with a Dw adaptor mounted in the hotshoe, an AutoFill Mode, it will work just like Canon E-TTL.
If preflash senses a dark suit or something dark filing frame, it pounds out the light. Also, if the risk is blown out highlights, in the background(?) you will have to be in ISO 100, and at least f/4. Quantum has a TIPS on their website, saying Q needs to be at least 7 feet from subject at ISO 200 and f/4 or wider to avoid over exposure on the subject.

In your instances, maybe just putting Mr. Q in Manual at low output may do the trick.
The two best things I did with my Quantum was buy the $45 Norman 19" Octogon softbox that opens like umbrella, and upgrading my T5d to T5-d-R and get a QNexus.

It takes tremendous flash power in bright contrast sun to under expose the background to the point where it is handsomely saturated and the pop flash to illuminate foreground.
I'm not clear on which problem you are experiencing, but I've been able to make Mr. Q do just about anything.
Best of luck. Jack