I have a Canon 5D Mark III which I'm using the TC-80N3 with. I'll be shooting moonbows at Yosemite this Monday, and needless to say I need to figure out how to work this thing.
I rented it from BorrowLenses and found the manual online, but I can't seem to still understand how the timer function works. Perhaps I'm simply not understanding how it works, but from what I remember, I should be able to set it to 30 seconds, and the moment I hit start, it opens the shutter until 30 and then releases it, correct?
Or is the timer just there for me to look at to know when to release the shutter?
Also is there any warnings of when the battery is getting low by chance? I know you can't shut it off, so I want to make sure it's going to last all day, being I have no idea how young the battery is.