I'm new to the world of flashes and transmitters and was thinking about grabbing the 600EX for the 5D Mark III, but mainly for the AF assist light. So I wanted to ask, do 3rd parties ever produce alternate AF assist lights? I've seen a few knock-offs of the ST-E2, but couldn't tell if they had AF assist or not.
I'm assuming the Canon ST-E2 itself is not an option as the 61-point AF is bound to have points at different places from the pattern in that unit.
It's been suggested that creating a matrix of NIR LEDs will do the trick, is this comparable to a patterned beam made for the camera's AF?
I'm also a novice at flash but I have a few to play with. The 600EX-RT is probably the way to go.
The Yongnuo ST-E2 is cheep and usefull on 2011 cameras.
On my 5D3 it fires prior to 1st curtain. Useless. Also it's AF assist is weak compared to the Canon flashes.
I've just tried focus into a dark room with various attachments. 5D3 w/- 24-105@105
1. 600EX shows a dense wide grid of deeep red light with reasonably quick focus. Reliable.
2. 580EXII very similar.
3. 430EX similar but weaker and slower.
4. Yongnuo has a week patern of vertical lines. I achieved focus with difficulty.
Go with the 600. Even though it is a big lump on your camera just to get a bit of light out there.
Or maybe a laser pointer or torch.