How to use slave flash without using onboard camera flash?

Question

I have a Canon t4i and a Neewer TT560 flash. I want to be able trigger the external Neewer flash without having the t4i's onboard flash actually fire. I have tried using the EasyWireless function but the camera's onboard flash still fires. The only alternative I know is a wireless transmitter, but I don't want to pay for one. Any ideas why EasyWireless isn't working?

Answer 1

"I have tried using the EasyWireless function but the camera's onboard flash still fires."



Are you sure the onboard flash is actually being captured by the camera? Pulse-triggered flashes communicate by sending or reading the coded flashes that occur *before* the shot is actually taken. It is possible that the onboard flash only sends the pre-shot pulse and stays dark while the shutter is open.



You may be able to manually set the onboard flash to a very low power while setting the external flash to full power.



Flashes can also sync by cable. You could probably get a hot shoe cable. There are also other connection types for flash sync—you might want to ask at a dedicated camera shop to find what system it uses and whether your equipment is compatible.

Answer 2

I just read the Neewer user manual

http://dynaphos.com/manuals/TT520-560%20Instruction%20manua.pdf



and the wireless flash section of the T4i manual

http://gdlp01.c-wss.com/gds/5/0300007695/01/eosrt4i-eos650d-im-c-en.pdf



There is not a single mention of ETTL in the Neewer manual. Also from the manual's rather poor illustrations it appears that the Neewer gun only has a single contact on the hotshoe - Canon speedlites have 5 contacts. The Neewer gun has no means of communicating with your camera. Your camera uses IR signal superimposed on the flash - your Neewer gun cannot react to that signal.



I think you have a simple manual unit that when used as a slave can be triggered by the light from the onboard flash but it doesn't have the IR comms facility that Canon speedlites have. You need that IR facility to use the T4i EasyWireless mode or any other remote in-built flash control using the camera as a master.



You are stuck with using the Neewer as a manual unit using the on-board flash as a trigger. Provided you don't set it to full power it should work just fine complementing your onboard flash but cannot act alone. Reason it won't work on full power is that the camera preflash will trigger the Neewer to fire. The camera's exposure calculation will use the amount of light gathered to determine how much light to add from the onboard flash. A millisecond later the exposure flash is fired and if your Neewer gun hasn't recharged or held enough power in reserve then it won't fire giving an under exposed shot.

Answer 3

A set of RF602 radio triggers cost £20 - hardly a lot. If you want to trigger an off camera flash without ANY input from an onboard flash, then this is the only way to do it.