Never tried "Mirror", watched some tutorials long ago, most of them quite lavish (but more accurate)...
Since i really need a mirror for current project, i decided to give it a try...
Simply put a cam in the center of mirror and played arround with cam-settings (Focal Length + Angle of view)...





Rendered cam and put in Diffuse-Chanel of mirror. Also here played around with settings till it worked (mirror horizontally!).





Quick and dirty,
Animation had NO priority and it took me from 0 (empty project) to 100 (finished result in Hitfilm) ca. 2 hours...
Mirrors are no problem anymore for me, even when the result scientifically is no accurate reflection.
And the effort is really minor (place cam in mirror and render...) :D



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