Old to the New Why anyone would choose to watch old science fiction movies over new ones beats me. Although a lot of today's sci-fi movies are older ones remade. The new science fiction films are more realistic with new special effects and have better sound.
The earlier movies had great special effects, but weren't as good as today's special effects, because now there's new computer technology. In today's films, spacecrafts and futuristic scenes are more realistic-looking, because they are images created by computers rather than actual models. So they have been given more details than in the earlier or even the original films. For example, spacecrafts can fly and maneuver a lot better. Also in the past, sometimes it could take months to complete just one model, as for today with the use of a computer you could make one model and duplicate it a thousands times with the click of a button.
Today cities and other planets appear to be very busy with many different species walking around, and hundreds of spacecraft zooming over the cities. As to before they always appeared to be pretty boring. The effect is that the cities look more believable.
Even the sounds of science fiction films have been improved. The sounds have been digitized. Explosions sound bigger. The exhaust sounds from the flying spacecraft are louder and actually sound like they're moving. Also, voices and noises in the movies seem to come from your right and your left side, which is a more realistic effect.
With the changes in movie technology, its getting harder and harder to stay away from the theater. And also by updating the older films, Hollywood is making sure that the classics never go out of style.