Impossible PX 70

PX 70 is the film that brought SX-70 cameras back from the dead. The Impossible Project launched it in July 2010, sixteen months after the team had announced their reinvented black-and-white emulsion and two years after Polaroid's Enschede plant rolled off its final batch, and the formula was rough at first. Early packs needed five minutes face-down in the dark to develop without going chalky, and the color was unreliable from one shot to the next, with sun on the developing image obliterating it and cold ambient temperatures locking it up. Even at room temperature you had to shield each photo for a long time, then come back to find a result that looked nothing like Polaroid's old Time-Zero.

The chemistry has improved across the decade. Impossible became Polaroid Originals in 2017 and folded back into the Polaroid name in 2020, but the underlying technology is the same lineage. PX 70 specifically targets the original SX-70 cameras, which expect a specific film thickness and integral pack structure that 600-series film does not match without an ND gel. If you have an SX-70 Sonar or a folding SX-70 from the 1970s, this is the film designed for it.

The palette is muted, with low contrast and a slight cyan cast under daylight. Skin tones come out softer than Fujifilm Instax Mini, and the warmth that defined original Polaroid SX-70 film is mostly absent. Some shooters consider this honest; others find it cold. It is not pretending to be Time-Zero. Compared to Polaroid Originals 600 Color it has a different base ISO and lens compensation requirement, so do not mix the two.

Development still benefits from shielding for at least a minute or two and from warm ambient temperature. Cold weather work needs a pocket or jacket for the freshly ejected frame.

Reciprocity exponent is 1.0. No correction needed past one second; the metered time is the shot time. Zone Light Meter still tracks the threshold but the math is a passthrough. In practice the SX-70's onboard meter handles most situations, and PX 70 is sold as eight-frame integral packs that fit original SX-70 cameras. Refrigerate sealed packs.