I've grown weary of the depressing gray background in the 3dview window, and wanted a sky I could see in edit mode, not just the render window. So, I made a sphere and deleted the lower half of it. Made a UV map, and did a google image search to find a hemispherical projection to plop on it. This looked really good (see attached). But, then I scaled it up by 500x and now it's all dark inside. So, I added a spot light. Changed the distance to 500, so it'd actually reach the dome. Changed the size to 180 degrees, hoping to light up the whole of the dome. When that didn't work I boosted the energy to 5... million. It lit up more of the ceiling, but the horizons are just as dark as ever. Does anyone have any good ideas of how I can make this thing look more like a sunny day, and less like the blackout at the superbowl?

While I'm waiting for a reply, I think I'll back up the un-scaled version and play with it until something squirts me in the eye.

Psst! There's nothing attached.

Well, there is now, fwiw.

Not that I know how to do it, I'm still learning; just thought you should know it (the attachment) wasn't there.
All the Blender tutorials on Lighting and Rendering and Compositing nice looking scenes use multiple lamps of various types, colors and intensity. Anyways, good luck!

Using a Hemi light should light up everything nice and even. Another option would be to make the material shadeless, then it won't depend on lighting.

Thanks, CMO, you've come through for me once again! But now I've run into another problem, when I view my scene from inside the dome.
If I'm viewing from below the horizon it works like I'd expect it to if I were above the horizon. If I move above the horizon, everything on the
grid is instantly obscured by a fog the colored by the part of the dome I'm facing. I think this is what's called a z sorting issue. I have no
clue how to fix it, but that won't stop me from trying.

To be 'inside the sphere' you have to be in perspective view.

D'oh!