Whew, thanks for all the replies, this flash stuff is confusing to say the least. What I have gathered is TTL helps set up the flash? Will it work with HSS?
TTL has nothing to do with HSS. HSS is a high Speed Sync. That means your flash instead of emitting one single burst under the sync speed emits multiple busts while the shutter slit is traveling across the sensor plane. But it does it at much lower power per burst. Over all one HSS volley equal to one Full Burst in supplied power so it will need 1.5 sec to reset. I have tried manually 1/128 power in HSS and could only take one shot in a burst of shots.
TTL is a metering related function. So now if TTL tells your flash to use more than 1/128 it might not make it depending if your shutter speed is too high.
The Ad200 from my little research after reading these posts is much brighter than the rest so what's the down fall? Does it have TTL? If I'm using HSS is TTL even still in play? I'd imagine I'd be using HHS a lot since I'd need my shutter speed way up to shoot wide open or close to it right?
Well, not necessary. You can use modifiers to reduce the flash power and still have your shutter speed in the sync with the flash. For example point the flash in to umbrella or through the umbrella. And since you are using the flash off camera you can also increase the distance between the flash and your subject. There are many things you can do to create exposure you want.
if I didn't go with AD200, are these other flashes stong enough in HHS with just one flash?
Read above.
isnt there a way to make my cannon flash fire once it sees another flash? Could be way wrong on that. Thanks for all the help guys!
Yes, if you buy receiver for Canon running at the same frequency and on the same channel as transmitter. It will not be TTL, obviously, but you can trigger it in the manual mode. You might even be able to change parameters on your Canon flash remotely.
I also want to say that HSS is not a very reliable way to set exposure since flash decides how much power per burst it needs to supply to cover your shutter speed. There are variations in each burst. So don't assume you can just crank the shutter speed up to lett less light from the flash in to the camera if your aperture is too bright. I would personally rely on light modifiers for consistency than HSS.