Objecting Lighting vs Lamps?

I’m still very new to Blender. But after watching a variety of different tutorials, in combination with a little experimenting of my own, I was wondering whether it was better to light your scene using a on object, such as a plane, or a lamp, such as a spot lamp, point lamp, etc.

I’m speaking in terms of Cycles, by the way.

Lamps are sampled more efficiently, so they’re a better choice if the available shapes work for you. Object lights need to deal with sampling multiple possible faces, so they tend to be more prone to noise. Note that an area lamp is the same shape as a plane object lamp, and a point lamp with size > 0 (that part is important!) has the same light shape as a sphere object lamp.

Point/spot/sun lamps with size set to 0 are non physical and will cast odd shadows and highlights. You should not set to size 0 unless you have a specific reason to do so.

If you need a glowing mesh, but it isn’t bright enough to significantly illuminate anything that isn’t right next to it (LED, bioluminensce, tron lines, etc), you can improve render speed by disabling “multiple importance sampling” in the material panel.

Something else to keep in the back of your mind is that, “there’s more than one way to do (anything).” An object will appear to “be glowing” when everything that the audience sees in the frame is acceptably consistent with the idea that “this thing is ‘glowing,’” and if nothing in the frame is inconsistent to that first-impression. It doesn’t actually have to emit light at all! “Anything that doesn’t look wrong … could be right (enough).”

Also remember that Blender has several available built-in rendering engines, now, and an excellent compositor. You’re free to use more than one rendering technique at the same time, building up “the final image” using whatever combination of techniques gives you “good enough,” fast enough and consistently enough to suit your project’s needs. “Cheating,” as they say, “is a virtue.”

One of my favorite techniques, for instance, is to illuminate everything (generally, in BI, not Cycles …) using lamps that do not generate shadows. Then, I’ll use a shadow-only spotlight to calculate where important shadows will be, and composite those into the scene. The shadows aren’t “complete and correct,” but they’re believable and render-time is drastically reduced. (Once the renderer has told me where the shadows are, and how dense they are, I can tweak them, color them, and so on using cheap, 2D, compositing techniques, with no further rendering required.