Nissin Di622 slave flash problem

[Darthchaffinch]

Hi, my Nissin won't slave flash off camera (is set to slave, and is supposed to flash from on camera flash). Anyone with one had issues please??

Thanks

EDIT:
seems like I need a 2nd pulse from the internal flash- plus less ambient light for it to work?!?

 

[Mike Jackson]

Is it the marl 1 or mark 2 flash. The mark 1 is only compatible as a slave with flash guns with a digital pre flash.

 

[Darthchaffinch]

its a Mk I, getting a pre-flash did set it off most of the time- not sure how I got a pre-flash on thuough..