The Cokin Red Center Spot filter has a clear center and diffused red edges. These diffused edges will be produce blur while leaving the center sharp. The filter effect is directly influenced by the f-stop and the focal length. A lens shot at f/1.4 will see a greater blurring effect than f/8.0 and a 85mm lens will see more blur than a 28mm. Additionally, a longer focal length lens will visually increase the size of the center spot area because it sees less of the filter area.

How to use Center Spot ?

• The shorter the focal length, the more visible the zone. As for the transition from sharp to soft, it depends on the aperture: the wider it is, the more diffuse the transition will be. For a correct adjustment with auto-focus reflex cameras, the choice of an AF central collimator is obviously required. We also recommend working with apertures of ƒ/5.6 or ƒ/8 in order to keep a sufficiently blurry transitional zone. A strong backlight brightens the effect of the filter.
• Uncolored Center Spot filters create blur around the central subject in a completely natural-looking way, giving the subject prominence in the image.
• Grey and Colored Center Spot filters work by blurring and darkening the periphery of the image in a more or less noticeable way. The intensity and the quality of the central subject’s lighting are clearly emphasized.
• Oval Center Spot filters are made for larger or taller subjects.