Hoo-boy, lighting. I've spent a lot of time learning about DAZ Studio lighting and I know I'm still only scratching the surface. This isn't a "how-to" article per se; there are better tutorials that cover that topic. This is just a grab bag of random tips to help you with lights. Cameras too.
As always keep in mind that everything that follows is based on my own opinions, experiences, and probably limited and faulty knowledge. Experts are welcome to weigh in and correct me; I'm just trying to include some basic ideas that I've noticed help my results.
Also be sure to go through some tutorials on lighting topics, such as the three-point lighting system. You'll be very glad you did.
To Dome or not to Dome?
The default lighting environment is called "Dome and Scene" and it's great for a beginner because it illuminates everything in the scene like a clear summer day. But the lighting is rather flat and uninteresting, not to mention unrealistic. In particular it doesn't cast any shad