I have one YN560II and want to add two more

Current YN560II is triggered via NPT-04 wireless with transmitter on my 60D and receiver on the YN560II.

If I bought two more YN560II, I'm assuming I don't need additional receivers on each flash? And if I'm reading correctly I can trigger each additional in S1 mode?

Or am I wrong? /holdsbreathe

The YN650II has an optical slave so you are not required to have a radio trigger on each to make them fire. The practicality of using optical slaves is another matter altogether. The two that would be in the optical slave mode in your proposed setup would need to be able to see the flash from the one using the NPT-04. On bright days or in some configurations thats less than desirable. In a closed room it should work pretty well.

Thank you sir...just wanted to confirm before I ordered. Not that it'll be a big deal if it didn't work outdoors and I'll just get more receivers at that point

At this point, I would get the new YN-560III for a few bucks more, since it'll play nice with the advanced features of some newer triggers.

To your original question, I often use my YN-560IIs in optical slave mode. Works well most of the time; doesn't work well when there are other people using flash nearby.

nathancarter wrote in post #16647485
At this point, I would get the new YN-560III for a few bucks more, since it'll play nice with the advanced features of some newer triggers.

To your original question, I often use my YN-560IIs in optical slave mode. Works well most of the time; doesn't work well when there are other people using flash nearby.

I was thinking last night too with certain modifiers the flash would be inside behind the diffuser which I'm assuming the optical sensor wouldn't see?

Aki78 wrote in post #16647522
I was thinking last night too with certain modifiers the flash would be inside behind the diffuser which I'm assuming the optical sensor wouldn't see?

Its an issue, but a lot depends on how close the slave light is to the one its optically mastering off of. Since you have 3 lights in the system put the one with the RF trigger inside the box.