I have 3 in 1 Neewer remotes, one transmitter and 4 receivers. Can I use the receivers to fire the flash and activate the shutter with the transmitter at the same time? I notice there is a flash and shutter or camera slide on the sides, does this mean all I can do is one or the other? I have a Neewer 670 flash unit and an El cheapo flash that came in the camera kit. I would like to use remote shutter and remote flash when pressing the remote transmitter button, not sure if that will happen. I am afraid to try.
Its Extremely unlikely, even if you could get the remote to fire both camera and flash, that they would be in sync.
Remember there is a (small) delay from pressing the shutter button, the only way to reliably sync the flash with the shutter is have the camera itself trigger the flash(es).
If you did manage to get the remote to fire both, its highly likely that thr flash would fire before the shutter has started to open.