The "red eye" effect, also known as the "red eye phenomenon," is a common issue that occurs when taking photos with flash photography. This phenomenon occurs when the flash of a camera illuminates the blood vessels in the retina of the eye, causing the subject's eyes to appear red in the photo.
The red eye effect is more likely to occur when taking photos in low light conditions, as the pupils of the eyes will be dilated to allow more light to enter. When the flash of a camera is triggered, the light from the flash enters the eye and is reflected back out by the blood vessels in the retina, causing the red appearance.
In regards to film cameras, it is possible for the red eye effect to occur when taking photos with flash photography. This is because film cameras also use flash units to provide additional light in low light conditions. However, it is worth noting that the red eye effect is more common in digital cameras due to the shorter flash duration and closer proximity of the flash unit to the lens.
There are several ways to mitigate the red eye effect when taking photos with film cameras. One method is to use a flash unit with a diffuser, which will scatter the light from the flash and reduce the amount of light that enters the eye. Another method is to increase the distance between the flash unit and the lens, which will reduce the amount of light that enters the eye.
It is also possible to reduce the red eye effect by having the subject look away from the camera when the flash is triggered. This will cause the pupils of the eyes to contract, reducing the amount of light that enters the eye and the amount of light reflected back out by the blood vessels in the retina.
In conclusion, the red eye effect can occur when taking photos with flash photography using a film camera. However, there are several methods that can be used to mitigate this phenomenon and prevent it from occurring in your photos. (Source: https://en.wikipedia.org/wiki/Red-eye_effect)