35mm

 is a standard film format, so named because of its 35-millimeter width. It is the largest-format film stock ever used for the recording of anything to do with Doctor Who. Because of its relatively high cost, it was infrequently used for principle recording, though it was sometimes used by BBC Enterprises for telerecording.

By far, the most ambitious use of 35mm was in the recording of the 1996 telemovie, which is the only Doctor Who story within the televised continuity to be entirely filmed in the format.

However, the BBC Wales team have occasionally used 35mm for certain scenes to which they wanted to apply traditional film effects. A good example is in the Tooth and Claw teaser sequence with the monks. There, 35mm was used when the monks were actually "flying" through the air. (DCOM: Tooth and Claw)