When you shoot Nikon and use the CLS/iTTL systen, you can fire remote flashes and set them to manual instead of TTL. This is well known since you set the options through the on camera menu.
In the Canon world, this is not possible: remote flashes operated by light control must use TTL. Right?
Wrong. Canon too supports this functionality.
Here’s a TTL flash set to slave mode (a 430 EX in this case). The display looks like this: (And note that the “M” here refers to the flash’s zoom setting – nothing to do with flash mode):
So it’s a TTL flash set to slave mode.
Now press and hold the MODE button. After a few seconds, you see this:
Now your cannon flash is still in slave mode, but it is now in manual power mode – TTL will not meter: the flash will just fire at whatever level you set it to (1/8th power, in this case). Note that the “M” to the left of the “1/8” now flashes, to remind you. One press and it goes back to TTL mode.
I bet there are some here who did not know this! Yes, you can use light-operated remote slaves that you set to manual, even in the Canon world.
PS: what’s that on the front of the flash? A Honl Photo speed strap plus a Honl 1/4″ grid.