I’ve sorted a couple of other issues in relation to camera projection, and I think I’ve now got it down. This statue is a photo, public domain, that I found on the web and brought into my scene. Statues could be really useful in garden shots. Need to keep the projecting camera in about the same place as the rendering camera, but use longer focal length to get the close up. That way the perspective is the same. And make the material single sided or strange shadows result.