Bizarre -- even by 70's Japanese "tokusatsu" (special effects series) standards, and highly entertaining. This series was produced in 1971 by P Productions, which in the mid-60's created Space Giants, a UHF TV staple of the 70's. Spectreman was, improbably, brought to US shores in 1979, eight years after its Japanese run, by Mell Welles, who was best known for his role as Gravis Mushnick in the original 1960 Little Shop of Horrors.
Like Space Giants, Spectreman would fight the same monster several times over the course of two episodes, presumably to save on monster suit costs. Also, like Space Giants, the series nemesis, Dr. Gori, was a space villain seeking to rule the earth (this time using giant "pollution monsters" as his tactic of choice) who operated from a flying saucer, wearing an exquisitely cheesy gorilla mask and blonde wig. No doubt this character was aped from Dr Zaius in Planet of the Apes, which was very popular in Japan. And, again, like Space Giants, optical effects were eschewed. Instead, P Productions used (and reused) animated sequences for transformations and various beam weapons to cut costs.
Unlike the many other transforming heroes of Japan, Spectreman was not in control of his transformation. He answers to his "overlords", an orb-like spaceship that he can't contact in cloudy weather. In some episodes he must drive to where there is no cloud cover to contact the overlords. Sometimes they will insist he transform. Sometimes he will request transformation, and will be denied. The overlords are positioned as wise overseers, similar to the "Methuselah" character in Space Giants, both of whom are prone to lecture the hero.
In re-watching the series, it seemed to get a bit of a budget boost around a 1/3 of the way into the series. The FX were incredibly threadbare in the first 10 or so episodes with most monster battles occurring in open fields. Then Spectreman started having battles in cities with building miniatures, creatures started to appear in oceans and lakes requiring access to a wet FX set, and fighter jet miniatures started being used, along with more pyrotechnics.
Overall, Spectreman is inspired early-70's Japanese cinema outre fun.
