According to this tutorial the solution to the distortion is to use the node setup in screenshot 2. However, the nodes completely mess up the image. Is there any other solution to get the edges straight?
2 Answers
The problem only occurs with spotlights. It works better with an area light. no distortion whatsoever.
I had the same problem. it turns out all you have to do is ensure you're using a Vector Math node, as opposed to a Math node. That's why your screenshot has a Clamp option (which the video does not).