While testing the POLAROID SX-70 LAND CAMERA SONAR AutoFocus I used film material from The Impossible Project. They develop instant film material for Polaroid cameras in both color and black & white. The film material is made in a former Polaroid factory in Enschede (Netherlands) which they bought in 2008. They basically had to reinvent new instant film material because it was already a dead technology and original color dyes were no longer available. Since their first new instant film in 2010 they constantly improved the quality of the material and the time it takes for the pictures to develop.
What might be of particular interest, is the film speed of the new Impossible instant material. The film for my SX-70, the Impossible SX-70 is described with ASA 160. The original film material from Polaroid was ASA 150. With these material unavailable since Polaroid stopped the production in 2005, many have modified their Polaroid cameras to use newer Polaroid material with film speeds up to ASA 640. They often used ND filters to correct for the wrong exposure time since the film is more then 2 times faster. ND Filters are also available by The Impossible Project if one wants to use their 600 series film material.
Although this does not seem to be necessary anymore with their SX-70 film, the difference between ASA 150 and ASA 160 is still noticeable. This can be addressed by setting the exposure dial on the camera to “darken”.
Unfortunately, by doing this, one looses the ability to adjust the exposure since all other setting lead to bad results. From left to right I tried “lighten”, “normal” and “darken”. Only with the “darken” dial set to maximum, I could create a more satisfying image.