I may take flack for this,so okay go for it. But I am hoping someone with this information fairly fresh in his or her mind can nail it for me before I have to go do the research and calculations myself, which would take a long time.
To make a long story short, I was using the Pocket Wizard Flex system with my 580EX II flash system. After several years of malfunctions, I gave up on them. One of the malfunctions was that the Canon 580EXs II blew all of their IGBTs and the flash would only dump full power. A really good read for you technophiles: http://photography-on-the.net/forum/showthread.php?t=1125902
Anyway, I'm now using the Phottix Odin controller and remote and they are truly remarkable. I've not had one misfire or wrong exposure with them.
I have noticed that I cannot turn the flash down low enough at higher ISOs or larger apertures. The Canon 580EXII can go to 1/128th power.
So I'm wondering if the flash is acting up again like it did on the PW Flex system.My technical question is what would be the distance to subject at any exposure setting where 1/128th on the 580EX II power would not be low enough for a correct exposure?
As always, thanks much for your time and effort.