I don't believe you need to worry about "the railfan-model-railroading-photo-police force" around here. There are more here that enjoy your talents than any that may ask “where does the reality end and the fake begin?”. Some of us play with trains and some are serious modelers and what your photos depict is exactly what serious modelers aspire to, realism. Me I play trains and my attempts at modelling are feeble at best that's why I am awed by your talents and your patience, "The set ups are a few hours of fun."
I always wondered how you added smoke. Now that you let us in on it shots like this are even more incredible to me.
I thought what you meant was you replaced the sky with the 1:1 smoke filled sky but with the exception of the smoke the above black and white sky is the exact same sky below.
So you pulling the smoke from a 1:1 picture and overlaying it, for lack of the proper term. onto to photo of your model?
