Using Plane Mesh as LightSource/Hide in Render? I am Trying to make an Intro Sequence with Plane Meshes to Light my Text.
Is there a possibility to restrict the rendering of these lighting planes, and yet still use them as a Light Source?
You tell Blender not to render any camera rays, meaning rays that go from the camera straight to the object. To do so you have to mix an emission shader with a transparent shader. Then you need the light path node. If a ray is a camera ray you'll want to use the transparent shader. If it isn't you'll want to use the emission shader. So you have to use the "Is Camera Ray" as the mix node's factor.

Node setup:



Example render without node setup:



Example render with node setup: