Advice on interior scene with 3 walls ceiling and floor

[rfollett]

I am trying to render a hotel conference room with large projection screen at one end.. The dark shots look great! With illuminated screens..

But I need a shot showing details.. What is best way to do this, add lights and make them invisible? Make the roof transparent?

Is there a material then lets light in (from the environment) but also acts like a diffuse to look at?

Thanks

Rich

[Speedster]

This trick may help, "depending".  For buildings and interiors, I often model a ceiling, some with beams (to cast shadows or whatever), but I apply a frosted glass to the ceiling to let some light through.  This way you can somewhat adjust the lighting by tweaking the glass settings, like Index of Refraction, roughness, etc.  At least it's worth a test.
Bill G

[Tim]

Rich

I removed my post as to not hijack yours.  I will post mine as a slightly different question.

For you situation you may want to consider at least two passes in combination with Bill's suggestion. 
1st pass = Everything dark with a ceiling included to get the video screens.
2nd pass = Lighted room or no ceiling.  I would first try the no ceiling route.
Merge the two shots in PS or some image editor.

Tim