This 1953 film is another film directed and produced by W. Lee Wilder, and co-written by his nephew Myles. There's lot of stock footage off the top as a UFO is tracked coming over the Pacific Coast of North America (Vancouver gets a shout-out). But suddenly as it appeared, the UFO vanishes over California. Then, while the police are checking some strange radio interference, two men and a women get attacked by a guy who looks like he's wearing a flight suit and a strange diving helmet. One of the men is killed. Then there's another killing.
Then helmet guy is seen at an oil refinery. He's cornered by the police, but then he removes his suit to reveal that he is actually totally invisible.
This is really a police procedural film (complete with Jack Webb/Dragnet style narration) as we follow the various levels of law enforcement tracking down the mysterious being in the strange helmet, and as such, it's not too bad. Yes, the alien's helmet is totally goofy-looking, but unlike the goofy-looking aliens in Killers From Space, he sticks mostly to the shadows. Except for when he's invisible, of course.
We never veer out of low-budget territory, but at least the film-makers are trying hard to make something with a little more intellegence than the usual run-of-the-mill 1950s sf-monster flick. The climax of the film does not include a shoot out, a fight, or an atomic explosion. The Day the Earth Stood Still is a clear influence, as by the end of the movie, the alien's actions are eventually considered to be nonthreatening and his acts of destruction accidental, and the climax of the film finally boils down to our inability to communicate with the alien.
And the scene on the poster never takes place in the movie.