The Schneider 4 x 5.65" 1mm Blue True-Streak Filter is designed to be used perpendicular to a point light source such as the sun, a light bulb, or a candle. Within the filter's glass is a combination of fine line types whose action is limited to point light sources. Upon those light sources, those lines create the effect of a scene or image that has been recorded with an anamorphic lens and then displayed using a complementary reverse projection lens. This can result in prominent, elongated streaks that are symmetric and extend horizontally from each point light source for the purpose of drawing attention to a specific part of the frame, or to create a visually dramatic effect.