Pany/Oly Remote - Pop-up flash as master > Off-camera flash as slave question

[FrankG]

M43 Panasonic / Olympus remote flash

I have bought a NIssin i40 as an off-camera flash for the Panasonic GX7 (wire-lessly). It is optically triggered by the pop-up flash. But I do not want the pop-up flash to illuminate the scene.
I see that i can set camera menu> 'communications light. to low' but that still allows the pop-up light to show in the scene.
Using the camera's FlashExposureCompensation probably affects only the remote off-camera flash, so that doesn't help to dial down the pop-up flash

I cannot find a piece of IR filter in gel form, as I've read sufggested suggested to place over pop-up, but I do have (I'm an old guy) a piece of developed slide film (frame 37:-) that I'm told could also work.
And I also have a piece of gel ND filter which I could attach to the pop-up with double sided tape.

Would either of these work equally well to eliminate the pop-up's illumination of the scene?
Is there a point at which the density of the film or the filter prevents the optical triggering from camera to remote flash from working (the off camera flash not seeing it)?

[vampire]

You can get a cheap diffuser for the popup flash that attaches to the flash shoe and put black tape over it. I got a cheap one that worked pretty well, I think off amazon. The main issue is that even at lowest power, it really drains the battery. This is for a center flash on a gh4 type camera. Not sure if it's an off center flash

[Remo Nonaz]

I picked up a pair of Yongnuo RF605C remote flash releases recently to use with my GH2 and they work very well. They will also control Yongnuo flashes, which do have a remote strength control. The remotes can also be used as a remote shutter control with the addition of a remote-to-camera shutter cable. You can even use these features together and leave the camera on a tripod and walk around with the flash attached to the 2nd remote, and when triggered, the flash will flash and camera takes the photo. Works very nicely.