Answers.Body: <p>Create 10 copies of your star field image. In an image-editing program (like Photoshop or GIMP), open the first image. Pick 10 stars at random, and make them darker/dimmer. Save that image. Open the next image.  Pick 10 different stars and make them dimmer.  Do that for all of your images.  In your video editor, cycle through the images, about 3/4 second each, dissolving from one to the next.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-01-19T20:02:53.053Z
Answers.LastActivityDate: 2017-01-19T20:02:53.053Z
Answers.UserDisplayName: BrettFromLA
Body: <p>I have an image file (jpg, 4K resolution) which is a bunch of stars in the night sky.  The image looks good when composited into a video clip, but the stars don't move or twinkle at all.</p>
  
  <p><strong>How can I make the stars twinkle?  (I tried searching for a star-twinkling effect, and I would accept one if such a thing exists, but what I'm really interested in here is the compositing problem of taking a static image and then animating it a bit.)</strong></p>
  
  <ol>
  <li>Different parts of the image should flicker/twinkle at random (do not do the whole image all at once, because all the stars in the night sky don't shimmer in the same way at the same time)</li>
  <li>I don't have time to keyframe every single star in the night sky.</li>
  </ol>
  
  <p>I'm using DaVinci Resolve 12.5 on Windows, but I also have access to a Mac with Final Cut Pro X and Motion.</p>
  
  <p><strong>What I have tried</strong></p>
  
  <p>I tried increasing the noise in the video, then setting the <code>blending mode</code> for the stars image to <code>screen</code>.  This makes it look like there is some movement in the shot, but it doesn't add twinkling.</p>
  
  <p>Also, Resolve has three effects: "Waviness," "Vortex," and "Ripples." I tried keyframing various parameters to introduce some movement/flickering into the shot.</p>
  
  <p>"Waviness" moves the sky itself, and even with all the parameters set to the smallest values it moves too much.</p>
  
  <p>"Vortex" adds some whirlpool-like movement.</p>
  
  <p>"Ripples" adds a shooting-star effect, which is cool, but not exactly what I'm looking for.</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-01-19T19:53:38.733Z
Comments.Text: I found a "twinkling star" video on YouTube that I think looks pretty good.  The creator says it's free to download. Here's the link: https://youtu.be/EZ7la-hMNuk  You could use KeepVid.com to download it. However, I think you'd only be able to get a 720p video.
Comments.UserDisplayName: BrettFromLA
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-01-19T21:36:17.580Z
Comments.Text: Do you have ae?
Comments.UserDisplayName: Alex
Tags: <compositing>
Title: How to make an image file flicker in a video? (stars twinkling)
UserDisplayName: Patrick Kenny
ThreadText: # How to make an image file flicker in a video? (stars twinkling)
  
  (Asked by: username_0 on 2017-01-19)
  
  I have an image file (jpg, 4K resolution) which is a bunch of stars in the night sky. The image looks good when composited into a video clip, but the stars don't move or twinkle at all.
  
  **How can I make the stars twinkle? (I tried searching for a star-twinkling effect, and I would accept one if such a thing exists, but what I'm really interested in here is the compositing problem of taking a static image and then animating it a bit.)**
  
  1. Different parts of the image should flicker/twinkle at random (do not do the whole image all at once, because all the stars in the night sky don't shimmer in the same way at the same time)
  2. I don't have time to keyframe every single star in the night sky.
  
  I'm using DaVinci Resolve 12.5 on Windows, but I also have access to a Mac with Final Cut Pro X and Motion.
  
  **What I have tried**
  
  I tried increasing the noise in the video, then setting the `blending mode` for the stars image to `screen`. This makes it look like there is some movement in the shot, but it doesn't add twinkling.
  
  Also, Resolve has three effects: "Waviness," "Vortex," and "Ripples." I tried keyframing various parameters to introduce some movement/flickering into the shot.
  
  "Waviness" moves the sky itself, and even with all the parameters set to the smallest values it moves too much.
  
  "Vortex" adds some whirlpool-like movement.
  
  "Ripples" adds a shooting-star effect, which is cool, but not exactly what I'm looking for.
  
  **Tags:** compositing
  
  > **Comments:**
  > **username_1**: I found a "twinkling star" video on YouTube that I think looks pretty good.  The creator says it's free to download. Here's the link: https://youtu.be/EZ7la-hMNuk  You could use KeepVid.com to download it. However, I think you'd only be able to get a 720p video.  
  > **username_2**: Do you have ae?  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2017-01-19. Score: 3 | Accepted answer
  
  Create 10 copies of your star field image. In an image-editing program (like Photoshop or GIMP), open the first image. Pick 10 stars at random, and make them darker/dimmer. Save that image. Open the next image. Pick 10 different stars and make them dimmer. Do that for all of your images. In your video editor, cycle through the images, about 3/4 second each, dissolving from one to the next.
  
  
  ---
  
  