In this shot is noticeable that there are two types of lighting, both similar, but different.
In one hand the set is lit by a pure red and there’s a medium high contrast between lights and shadows. On the other hand, the characters are lit by different light sources. As can be appreciated the characters are lit by a red and also by a white light. The difference is also in the shadows that the characters drop on the surface. This shadow are totally different as the one that are on the cliff, the characters almost don’t produce shadows, something totally different as the rocks on the ground.
One last final thought is that the scale is not quite interesting and is evident that this was shot on chrome key, but it will be wise to analyze this visual effect compared with the movies on that same era.