Film stock showing correct image tonality directly—no negative step required. Historically cinema prints, now mainly archives and 16mm niche work. Digital cameras technically output positive signal.
Do you need film stock that you can view immediately without going through a negative-to-positive reversal in the lab? This used to be the classic way for cinema prints — and positive stock does exactly that. The material shows the tonal rendition directly correctly: bright stays bright, dark stays dark, colors are recognizable in their original form. No detour via negative development, no intermediate step. Practically, this means: you shoot on positive material, have it developed, and immediately get a projectable or viewable image back.
Historically, this was the standard solution for cinema prints in the 35mm range — the positive stock was exposed directly from the negative and then put into projection. The reason was economic efficiency: a print was created directly in positive form. Today, this process is practically obsolete for narrative film because the digital intermediate pipeline has long since replaced it. However: 16mm positive stock is still used for certain documentary and archival projects, as well as for artistic works that consciously rely on analog processes. You shoot 16mm, develop directly to positive, and immediately have a projectable original — without negative management, without additional costs for intermediate steps.
Practically on set: With positive stock approaches, you have to rely on your exposure — there is no negative latitude, no room for massive over- or underexposure. The latitude is tighter. This demands precise metering and consistency. With the classic negative workflow, you have about 2–3 stops of safety margin; with positive material, you work closer to the edge.
An important point for your understanding: digital cameras technically produce a positive signal — the sensor already delivers the correct tonal rendition, not inverted. This is a conceptual difference to analog film technology. When you work with digital cameras, you are de facto making positive recordings, even if you later save in DCP or Log format. This is one of the reasons why the digital world is so transparent to post-production: there is no negative reversal that needs to be interpreted. You see what you have recorded — immediately.