Jennifer, the Team Leader for Film & Chemistry at Polaroid, has added a few technical details on Instagram:
1. The new chemistry includes colour stability improvements that ensure that the frames remain black and white, instead of brown and white as they age. Some examples of this effect can be seen in my review of the SX-70 film: analog.cafe/r/polaroid-ban…
2. The ratio of TBHQ (or tertiary butylhydroquinone), a black and white developer that was first talked about at length when Polaroid released their Reclaimed Blue frames (analog.cafe/r/polaroid-rec…) has increased. In turn, this appears to have bumped the micro-contrast/sharpness of the photographs (this answers my question about the new chemistry above).
3. Further tweaks seem to have dramatically improved the overall contrast ratio/extended the dynamic range of film. As you can see in the side-by-side example posted below, the new chemistry (left) shows greater shadow *and* highlight detail. In short, this means it’ll be easier to avoid over- and under-exposing Polaroid film, which is known to be the greatest issue with the emulsion.
All of the above is very good news. I’m glad we’ve got more context about the improvements; looking forward to running my own tests with this film!
Dmitri