Optical Glow

OPTICAL GLOW

A blazing fast, drop-dead gorgeous, photo-realistic glow effect for After Effects and Premiere Pro.

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About Optical Glow

Optical Glow is a realistic glow effect that tries to simulate how light actually behaves. It mimics the inverse-square falloff of actual light, where brighter things glow both more intensely and also appear to glow “larger” than dimmer things.

Optical Glow is a 32bpc effect in After Effects, so it works with, and can generate, HDR values. When used in a lower-bit-depth project, its internal calculations are still done at 32-bit.

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Getting Started

• Drag the Optical Glow effect onto your clip, or apply it from the Effects Menu.

Modify the Effect

• My Footage Is contains options that help Optical Glow determine how best to blend its effects. Select Video, Log, or Linear depending on whichever footage type is getting worked with. Video is chosen by default as minimal adjustments are made.
• Amount adjusts the intensity of the glow effect.
• Size controls the overall radius of the glow. Note that brighter sources will appear to have a larger glow radius than dimmer ones, depending on the Falloff setting below.
• Falloff modifies the brightness relationship between the inner and outer regions of the glow effect. The default value of 100 creates a realistic, inverse-square light falloff. Higher values increase the “tightness” of the glow, making the core brighter and the outer edges of the glow dimmer. Falloff values below 100 soften the glow effect, creating more of an appearance of diffused light.
• Highlights Only controls which luminance values of the source image contribute to the glow effect. This control is similar to the Threshold control in other glow effects. At the default of 0%, the entire source image contributes to the glow. Increase this value to gradually restrict the glow to brighter values. Note that since Optical Glow works on 32bpc sources, this value can be set above 100%.
• Highlight Rolloff provides a way to adjust the bright core of the glow effect. Because Optical Glow respects and generates HDR pixel values, the brighter areas at the core of the glow can appear harshly clipped. Highlight Rolloff gently suppresses these HDR values to bring them back into the 0–100% range of pixel values. This can create a pleasing look, with the core of the glow maintaining color saturation and a softer appearance.
• Color
  • Vibrance increases the color saturation of the glow effect.
  • Colorize adjusts the overall color of the glow effect. Use this to subtly tint the glow, or to add color to a monochromatic element.
  • Inner Tint and Outer Tint selects tint colors of the inner and outer areas of the glow, respectively.
• Glow Only blends between the final result of the glow effect added to the source image (0%) and the glow element on its own (100%)
• Dimensions determines whether the glow extends on the Horizontal or Vertical axis, or both at the same time.
• Quality determines the smoothness of the glow effect. Higher quality settings may increase render times. Generally you can leave this setting at Production and not worry about it. Only with very large or intense glows will you tend to see any difference at the various quality settings.
  
  • Draft is the fastest setting and can look fine at smaller Amount and/or Size values.
  • Production the best choice for most applications, providing a blend of speed and smoothness..
  • Best is a good choice for very large, and/or intense glows.
  • Extreme provides the best quality, which is more noticeable with very large, very intense glows.
• Alpha Channel controls both how the alpha channel of the source image (if any) is treated, as well as whether or not an alpha channel is generated. Note that glows are best composited additively, so generating an alpha channel for a glow effect is often not the best way to work with a glowing element.
  
  • None the effect renders with a solid alpha. If the source layer has any alpha channel, it is replaced with solid black. This allows Optical Glow to control how the glow is blended, for maximum quality
  • Preserve Original respects whatever the original alpha channel information was on the clip the effect was applied to. If the glow effect extends beyond the boundary of the original layer’s alpha, it will be cut off.
  • Extend (Unmult) adds alpha channel information from the glow on top of whatever alpha channel information was already present.
  • Generate (Unmult) ignores the source layer alpha, but generates a new alpha channel based on the brightness of the glow effect.