Bounce Card or Emissive Lights (what is the difference)

When Im looking for area lights. I see 2 different methods in tutorials. 1 is using the bounce card method (pointing a spotlight on to a white plane) 2 is putting an emissive material on a plane. Option 2 seems a lot easier. What would be the benefit of using method 1? Isn’t the effect the same?

Bounce card will only give bounced indirect lighting while emissive light will give you, well, light.
Option 1 is somewhat to close to method used in photo studio to get soft indirect shadows, while for actual area light you might want to use emissive.

These options are not aimed at achieving same effect. You would use bounce card for something like faking bounced light from ground outside the window lighting up your interior. Emissive surface would be used to make a light bulb, for example.

Thank you. I am lighting my interior with a Direct light. A sky light and Planes with emissive material. Can I compare the plane with emissive material with the Vray “Skylight Portal” option?

UE4 has its own skylight portal. It is called Lightmass portal.

thanks! great!