First of all, as good as the Patterson Sasquatch film is…it is still a rather “low contrast” film. This is why a lot of surface detail is hard to distinguish and why a lot of misinterpretation occurs. Everything that reflects light has its own “intrinsic brightness” levels. Astronomers call this “albedo”. There is much that can be done to enhance the contrast and thus distinguish the tones from one another. Filtration is one. This is done prismatically. A color split, either using glass color filter, or using digital technology to split the colors. An imperfect lens, which is nearly all lenses, will not focus all colors to a single point. Some of the colors remain out of focus and contribute to the over all unsharpness of the image. Removing these colors sharpens the image significantly. The remaining colors in the image can then have contrast boost applied to them. Digitally this would mean that tones that are described mathematically by numbers that are close to the same, can be reassigned numbers that are greater and lesser, to make the tones diverge and boost the contrast. This is not altering the image, it is taking what is already there, and making it more seeable, which is called “enhancement”. Understanding surface brightness and why one part of an image would have a different tone than its surroundings is a prerequisite for film interpretation. In other words, for instance, “Patty’s” head has one tone on the side, and another tone on the crown and down the back of the neck. Why would the film record this as “two” toned. The surface reflectivity changes along the crown of the head and down the back of the neck, mostly due to a marked difference in “curvature” in that area. In other words the curve of the reflective surface changes and thus less light is reflected back to the camera and to the film plane. Now for a general head of hair, this does not usually occur, but if the hair has been bound in some way into a “bunched” arrangement, then it reflects less light back to the camera due to its now “curved” surface. This results in the image recording that area as significantly darker. When the film gives you this tonal divergence, then the divergence can be driven further apart through value reassignment of the two tones and then what’s on the head leaps into view. Here’s an example. On the left is the raw image. On the right is the filtered image. The part that is curved or bunched reflects less light to the camera and appears darker. It is visible from the crown of the head down the back of the neck to the back. Click on the image to enlarge.
Here’s another example. Once again, notice the darker area from the crown of the head…down the back of the neck. Click on the image to enlarge.
Here’s an animated file where each frame is filtered. The hair on the side of the head is significantly long enough to blow in the wind some as she moves forward. Click on the image to animate.
In the filtered animation below, the head can be followed in a turn toward the camera and back. When the head is looking away the dark “bunched” hair can be seen. Click on the image to animate.
In this full color animated sequence the same dark area down the head and neck to the back can be seen…illuminated by the brilliant sun. Click on the image to animate.