The Time Travelers (also known as Time Trap) is a 1964 science fiction film directed by Ib Melchior and starring Preston Foster, Philip Carey, Merry Anders, Steve Franken, John Hoyt, and Delores Wells. The cast also includes superfan Forrest J. Ackerman in one of his many bit roles in science-fiction films.
In 1964, a team of scientists is trying to develop a view screen into the future. What they in fact get is a portal and they soon find themselves on the other side, 107 years into the future in the year 2071, when the portal collapses. The Earth of the future is barren and they are soon attacked by mutated humans but rescued by a group of scientists who are building a spaceship to take them to a new planet. They learn that much of Earth was destroyed as the result of a nuclear war. When it's determined that the visitors from the past cannot be included in the planned voyage, they work furiously to rebuild the portal and return to their own time before departure day.
Meanwhile, always under the threat of attack from the mutants, friendships are formed and they learn of life in the future including the use of robots for menial tasks. An aged and out of shape Preston Foster leads a small group of scientists through a time portal into a future where nuclear war has decimated the Earth and the few humans left are holed up in a mountain stronghold. Outside, hostile mutants roam the arid wasteland. The concept is fine, and the acting passable, but the cardboard sets are from hunger. Irwin Allen, never one to pass up an opportunity, stole the basic elements of this Ib Melchior movie for his 'Time Tunnel' TV show.
It also appears to have strongly influenced certain 'Star Trek' episodes. The main reason to watch this moldy oldie is to see the lovely Merry Anders wearing skintight jumpsuits and also doing a nude shower scene. Several other undressed and semi-dressed Hollywood starlets are in the shower scene with her. Plants vs zombies heroes hacked.
Shot in color, which is a good thing, and a pretty decent musical score helps a lot. Worth a look for what passed for a sci-fi flick in 1965. Big changes in the genre were only a few years off, of course.