Why is there a red halo effect with Cinestill film?

Cinestill film, a popular motion picture film stock used for still photography, is known for its distinct red halo effect around high-contrast edges in photographs. This phenomenon is a result of several factors, including the film’s anti-halation layer, its high contrast, and the type of developer used in the developing process.

The anti-halation layer in Cinestill film is designed to reduce halos and prevent light from reflecting back through the film. This layer is made from a material that absorbs light, but unfortunately, it also absorbs certain wavelengths of light differently, resulting in the red halo effect. The anti-halation layer’s color is red, which is why the halos produced are also red.

Cinestill film has high contrast, which is desirable for motion picture photography but can result in issues when the film is used for still photography. The high contrast creates many high-contrast edges that are more likely to produce halos and fringing, further amplifying the red halo effect.

The type of developer used to process the film can also play a role in the red halo effect. Some developers are more prone to producing halos, while others are less likely to do so. Additionally, the developing process can affect the contrast of the image, which can also contribute to the red halo effect.

In conclusion, the red halo effect in Cinestill film photographs is a result of the film’s anti-halation layer, high contrast, and the type of developer used. While some photographers may view it as a flaw, others embrace it as a unique and desirable characteristic of the film. Understanding the underlying causes of the red halo effect can help photographers make informed decisions on how to approach it in their work.