The Expansive World of Filters

The Expansive World of Filters

What is a Lens Filter:

A lens filter is a camera accessory that cinematographers use to control the image. On the surface, a filter is a protective glass that can slide in and out of the matte box in order to eliminate the possibility of extra dust, dirt, scratches, and obstructions that could damage the lens.  Apart from their rudimentary use, filters are an excellent way to have more leverage in manipulating the image. Certain filters can enhance colors by adding or subtracting hues and intensifying or dulling the saturation of particular colors. This in turn adds contrast to the image and creates a more vibrant picture. The most used filters are those that affect the exposure of the image by limiting the amount of light that is allowed to pass through the shutter. These filters have varying degrees of how much light they block, and ultimately protect the cinematographer from overexposing the image. There are also filters that can be used as visual special effects by creating a type of obstacle illusion in front of the sensor like Schneider’s True-Streak filters. 

What is Schneider’s True-Streak Filter: 

Just like any filter, the true-streak filter is placed in front of the lens in order to manipulate the image. Once placed in the matte box, the true-streak filter essentially exaggerates or mimics an anamorphic flare. When light passes through the filter, a hued streak cuts through the light’s source. Based on the source’s size, scope, and intensity, the flare can vary in size. The brighter the light source and specular reflections, the more intense the streak will be. Because anamorphic lenses have a unique internal glass structure, when light passes through the lens it reflects, refracts, and essentially “bounces around” before it reaches the camera’s sensor. Once the light reaches the sensor, a horizontal flare will result based on the angle in which the sensor is receiving the light. These filters work best when using point light sources to create fullest visual effect. 

Size, Intensity, and Color:

While blue is the most common solid color, there are other colors that streak filters come in. Schneider produces colors in Orange, Green, Yellow, Violet, Pink, Gold, and Clear. There are also rainbow streak filters, which merge all the color streak filters into one glass. This special effect seamlessly creates a rainbow gradient streak wherever the light source is. Opposed to the true-streak rainbow filter, the true-streak confetti filter creates small multi-colored streaks around a light source. This filter creates firework-like bursts that streak through and around the source. 

Based on how far apart the colored lines are from each other on the physical filter, determines the intensity of the streak. The closer together the lines are will great the strongest streak. In other words, the 1mm true-streak filter is more intense than the 4mm filter. At Bokeh, we offer the True-Blue Streak in 1mm, 2mm, and 3mm.  

Using True-Streak Filters:

These filters can either be inserted to a conventional 4x5.60 matte box tray or be gear-driven in order to quickly rotate the streak to a desired angle. Like mentioned before these filters can enhance anamorphic lenses that already naturally create streaks and flares simply due to the mechanics of the physical lens. But what if you are shooting with non-anamorphic lenses and desire the streaks to fit the look of your project? These true-streak filters in front of your lens will imitate the anamorphic optics and help achieve your look in a cost-effective way. These filters also enhance highlights and helps to draw attention to a specific part of the frame.