Read this: Spectre had its world premiere in London on 26 October 2015 at the Royal Albert Hall, the same day as its general release in the United Kingdom and Republic of Ireland. Following the announcement of the start of filming, Paramount Pictures brought forward the release of Mission: Impossible – Rogue Nation to avoid competing with Spectre. In March 2015 IMAX corporation announced that Spectre would be screened in its cinemas, following Skyfall's success with the company. In the UK it received a wider release than Skyfall, with a minimum of 647 cinemas including 40 IMAX screens, compared to Skyfall's 587 locations and 21 IMAX screens.
Now answer this question, if there is an answer (If it cannot be answered, return "unanswerable"): What movie prompted IMAX to show Spectre?
Skyfall