Troubled Production: Tarkovsky spent a year shooting the film in Estonia with cinematographer Georgy Rerberg, using an experimental filmstock from Kodak. The two argued constantly over the script, with Rerberg constantly pressing for rewrites. It was later discovered that all the footage sent back to Moscow had been improperly processed at the laboratory, and Rerberg left the production by simply walking out of the screening room and never coming back. Tarkovsky managed to convince Mosfilm to start all over again as two-part film but with half the budget, with each part being released a month apart—the film is usually seen nowadays as a whole, with an interval. Production designer Rashit Safiullin claims the final version was very different to the original footage, but other crew members who worked on both shoots claim they were almost identical. There are reports of some footage (either from the first or second shoot, it's not clear) being destroyed by fire, and some claim Tarkovsky actually shot the film three times. Other problems included having to recreate the remains of the troops sent into the Zone with only five tanks when the original shoot had twelve, and the fact that some of the locations were polluted with toxic waste; the "snow" in one scene was actually an irritant chemical spewed out of a chemical works across the river. Many of the cast and crew, including Tarkovsky himself, later contracted cancer as a result. In addition, Tarkovsky actually had members of the crew physically paint the landscapes because he wanted the grass, trees and bushes etc. to look a specific way.
The Strugatsky Brothers had to write thirteen versions of the script until they nailed the one which satisfied both them and the director.