Do not use C4D's "Render to Picture Viewer." Use the V-Ray Frame Buffer.
Heads up: There is no "crippled" free version. Unlike some software, Chaos does not offer a free tier with a logo watermark. Your only legal free options are the Trial or Education license.
When you install V-Ray for C4D, you are getting five major tools: Do not use C4D's "Render to Picture Viewer
Why is V-Ray considered "Ultimate"? Because it is a language spoken globally. If you learn V-Ray in Cinema 4D, you can walk into a job using 3ds Max, Maya, SketchUp, or Rhino and already know 80% of the material editor and lighting settings.
For the Cinema 4D artist, V-Ray is the bridge from being a motion graphics designer to being a visualization artist. It turns a 3D scene into a photograph. Heads up: There is no "crippled" free version
The term "free download" is the most searched phrase in the 3D community, but it comes with caveats.
The Official Route: Chaos Group does not offer a fully functional, permanent free version of V-Ray. However, they offer the next best thing for professionals: a 30-Day Free Trial. This is the "ultimate free download" because it gives you unrestricted access to the full software. It allows you to stress-test your hardware and see if the workflow fits your pipeline before committing to a subscription or perpetual license. When you install V-Ray for C4D, you are
The Educational Route: For students and educators, Chaos Group is incredibly generous. They offer free educational licenses for V-Ray for Cinema 4D. If you have a valid .edu email address or proof of academic enrollment, you can download a fully functional version of the engine for the duration of your studies. This is the legitimate way to master the engine without cost.
If you are a student, a hobbyist, or a professional wanting to test, here is the official way to get "The Ultimate Introduction to V-Ray for Cinema 4D" for free.