film techniques - Would special effects for early movie patrons seem real?

When I watched The Walking Dead on my 1080i HDTV, the special effects looked seamless. In other words, I knew what I was watching was fake, but it was hard to tell.

When I upgraded to a 1080p HDTV, the show looked more like a Soap Opera and the Special Effects were not as impressive; mainly because the scenes containing CGI stood out like a sore thumb.

Early black and white films with special effects have always seemed this way to me. However, I've only watched them on Television.

If I were sitting in a 1950s movie theater, would my naked eye be able to distinguish real from fake using the technology from that era?