Answers.Body: <p>In After Effects, I think you'll need a 3rd party plug-in to do this. One option is <a href="http://www.redgiant.com/products/trapcode-sound-keys/" rel="nofollow">Trapcode Sound Keys</a>. Another is the Frame Manipulator plug-in from <a href="http://aftereffect.pluginsworld.com/plugins/adobe/1746/digieffects/buena-effects-pack.html" rel="nofollow">DigiEffects' Buena Effects Pack</a>.</p>
  
  <p>You can do this in Apple's Motion using the Parameter > Audio behavior. Apply it to your audio track, then apply a Brightness filter to your footage and set the "Apply To" of the behavior to the filter's Brightness parameter. You'll need to adjust the parameters of the behavior to suite your audio and video.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-06-16T02:12:24.100Z
Answers.LastActivityDate: 2016-06-16T02:12:24.100Z
Answers.UserDisplayName: user1118321
Answers.Body: <p>The pulsating light is just the intensity of the light varying over time. There are various ways of doing that, you could keyframe it (if you had nothing better to do), you could use an expression like <a href="https://www.lynda.com/After-Effects-tutorials/wiggle-expression/79651/117518-4.html" rel="nofollow noreferrer">wiggle</a>, or the "<a href="https://helpx.adobe.com/after-effects/using/assorted-animation-tools.html" rel="nofollow noreferrer">the wiggler</a>" tool (if you're old school), or you could control it with the audio level of a layer that has audio.</p>
  
  <p>If you're trying to drive the intensity of the light from the audio, then you need to first convert the audio levels to keyframes. Right-click the footage with the audio, and choose <strong>Animation>Keyframe Assistant>Convert Audio to Keyframes</strong>, or with the audio layer selected go to the <strong>Animation</strong> menu in the menu bar and choose *Keyframe Assistant>Convert Audio to Keyframes**. Then you can use those keyframes by either copying and pasting to your light's intensity property (and tweaking the values in the graph editor), or using an expression. This <a href="https://video.stackexchange.com/questions/18586/i-want-to-add-video-noise-grain-based-on-an-audio-track/18596#18596">answer</a> details how you do that.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-06-16T11:27:53.507Z
Answers.LastActivityDate: 2016-06-16T11:27:53.507Z
Answers.LastEditDate: 2017-04-13T12:46:08.110Z
Answers.UserDisplayName: stib
Body: <p>I've seen this effect in a lot of lyric video, particularly when the music is quite intense. Please see these videos for references:</p>
  
  <p><div class="youtube-embed"><div>
                  <iframe width="640px" height="395px" src="https://www.youtube.com/embed/eiIFO54jJZA?start=0"></iframe>
              </div></div>
  <div class="youtube-embed"><div>
                  <iframe width="640px" height="395px" src="https://www.youtube.com/embed/zasaUL70Oc8?start=0"></iframe>
              </div></div></p>
  
  <p>There is a constant pulsating/flashing light effect</p>
  
Tags: <after-effects><lighting>
Title: How do I achieve a "throbbing light" effect in After Effects?
UserDisplayName: Ryan Dias
ThreadText: # How do I achieve a "throbbing light" effect in After Effects?
  
  (Asked by: username_0 on 2016-06-15)
  
  I've seen this effect in a lot of lyric video, particularly when the music is quite intense. Please see these videos for references:
  
  There is a constant pulsating/flashing light effect
  
  **Tags:** after-effects, lighting
  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_2 on 2016-06-16. Score: 1 | Accepted answer
  
  The pulsating light is just the intensity of the light varying over time. There are various ways of doing that, you could keyframe it (if you had nothing better to do), you could use an expression like [wiggle](https://www.lynda.com/After-Effects-tutorials/wiggle-expression/79651/117518-4.html), or the "[the wiggler](https://helpx.adobe.com/after-effects/using/assorted-animation-tools.html)" tool (if you're old school), or you could control it with the audio level of a layer that has audio.
  
  If you're trying to drive the intensity of the light from the audio, then you need to first convert the audio levels to keyframes. Right-click the footage with the audio, and choose **Animation>Keyframe Assistant>Convert Audio to Keyframes**, or with the audio layer selected go to the **Animation** menu in the menu bar and choose \*Keyframe Assistant>Convert Audio to Keyframes\*\*. Then you can use those keyframes by either copying and pasting to your light's intensity property (and tweaking the values in the graph editor), or using an expression. This [answer](https://video.stackexchange.com/questions/18586/i-want-to-add-video-noise-grain-based-on-an-audio-track/18596#18596) details how you do that.
  
  
  ---
  
  ### Answer by username_1 on 2016-06-16. Score: 0
  
  In After Effects, I think you'll need a 3rd party plug-in to do this. One option is [Trapcode Sound Keys](http://www.redgiant.com/products/trapcode-sound-keys/). Another is the Frame Manipulator plug-in from [DigiEffects' Buena Effects Pack](http://aftereffect.pluginsworld.com/plugins/adobe/1746/digieffects/buena-effects-pack.html).
  
  You can do this in Apple's Motion using the Parameter > Audio behavior. Apply it to your audio track, then apply a Brightness filter to your footage and set the "Apply To" of the behavior to the filter's Brightness parameter. You'll need to adjust the parameters of the behavior to suite your audio and video.
  
  
  ---
  
  