Impossible B&W Film for SX-70 Impossible black & white instant square frame film for SX-70 type Polaroid cameras & the Instant Lab, with classic white frame. Images emerge in 20 seconds, giving a finished, fully-developed picture in five minutes. The B&W SX-70 film develops in normal light conditions without the need to shield or protect from sunlight. Tones are accurate, contrast is rich & vivid, with a fresh, clear & sharp final finish.