Lights in Cinema 4D share much with their real world counterparts. Depending upon your settings, you can create lights with shadows, lights without shadows (very handy!) and lights that actually are visible in your final render. Like the real world, if your scene has no lights within it, or all of your lights are turned off, then your rendering will be similar to a black cat in a coal mine—that is, black. You may have an alpha mask without lights, however, and that can come in handy with compositing from time to time (depends on your render settings).
Cinema 4D supports all light types since the beginning of computer graphics, the omni, spot and infinite lights. These lights tend to produce artificial results, which is no surprise given their age. Newer types, such as area, IES and sun lights can produce much better results in terms of realism, though at higher render times, or higher quality render engines (advanced and physical). With the right settings (on all of the lights), you can get some really great results. Since many of the rules of CGI lights mimic the real world, it helps to pay attention to real world lighting techniques. One of the most important techniques is to put some distance between your lights and your subject, and use the inverse square fall off features. The light energy will diminish over its distance, and you want to catch the “sweet spot,” where its not too bright, and not to dim, and with good color purity.
Using the inverse falloff feature can take some getting used to, especially if your handy with traditional CG lighting techniques. But if you put some time into it, you will be happy with the results.