• Adobe After Effects

  I’m stumped, trying to do a night traffic cars streaks with real time camera footage

  Posted by John Mayer on January 14, 2013 at 3:26 pm

  Hello,

  I’ve been trying to make some night traffic car streaks on a road with a steady camera live shot. The similar effects we can see on very long exposure photos. The closest I got to this is by using Echo effects and isolate the car lights on a masked layer, but the echo doesn’t repeat enough or doesn’t get enough inbetween to make streaks (it rather make doted lines effect). I sense that my footage has not enough frame rate (15fps) as the goal was to make the footage compressed into 5-10 seconds. Maybe I have to reshoot the film with an higher fps, but I just want to check out if there’s other solutions I could try if someone know a better method.

  Thanks!

  Here’s a reference of what I’m trying to do:
  https://www.youtube.com/watch?v=Nwm46hiFNBQ

  at 0:53 second mark, that is something similar but with longer streaks, similar to this: https://i.imgur.com/ciCzE.jpg

  Some contents or functionalities here are not available due to your cookie preferences!

  This happens because the functionality/content marked as “Google Youtube” uses cookies that you choosed to keep disabled. In order to view this content or use this functionality, please enable cookies: click here to open your cookie preferences.

  Tudor “ted” jelescu replied 13 years, 3 months ago 3 Members · 2 Replies
• 2 Replies

• 

  Kevin Camp

  January 14, 2013 at 10:52 pm

  the problem with trying to recreate long exposure photography with video, is that the exposure time for a photograph may be upwards of 10s of seconds to several minutes to get the streaking.

  that means that you be shooting video at just a few frames per second to 1 frame per couple minutes…

  to try and do this in post with video, try shooting at a higher frame rate but also a slow shutter speed (or wide shutter angle). you’d like the shutter speed to be near the frame rate (so if you shoot 29.97, you’d want the shutter speed to be 1/30th of a second), or if you use shutter angle set it to 360, or as wide as you can get it to capture as much motion blur as possible in each frame.

  that should reduce the dotted line effect when you use frame blending (or similar effects like echo, wide time or time blend — time blend would be my choice for this, it’s fast but quirky if you’ve never used any of the cc time effects).

  you may be able to use what you have, but you’ll need to try and interpolate frames in between the fames you shot to try and fill the gaps in the lights. you can see how far using time stretch and frame blending can get you, or try the timewarp effect.

  then try using echo (or time blend, wide time) on the frame blended/timewarped footage.

  Kevin Camp
  Senior Designer
  KCPQ, KMYQ & KRCW
• 

  Tudor “ted” jelescu

  January 15, 2013 at 10:09 pm

  With Trapcode Particular you can create the light streaks – only it will take you some time to track all the lights on the cars and animate AE Lights as Emitters for the particles.
  You may try to key out the lights, comp them on black, precomp and then time remap the precomp to get more frames. Render and import that in a higher frame rate comp- 48-60 and try Echo or posterize time to see if you get better results. You will have to time remap again to match the length and frame rate of your final and comp the result on top of the original footage using Unmult or a transfer mode like Add.

  Tudor “Ted” Jelescu
  Senior VFX Artist

Reply to this Discussion! Login or Sign Up