How to create a star filter for night time lights

DavlonDavlon Website User Posts: 283 Just Starting Out

I seem to remember seeing a tutorial on this, but I cannot find it now. 

How can I create a cross screen/star diffraction effect on nighttime footage with bright lights?

Do a google image search for "star filter effect"





  • DavlonDavlon Website User Posts: 283 Just Starting Out

    No one around?

  • tddavistddavis Moderator, Website User Posts: 4,196 Moderator
    edited October 2017

    @Davlon Not sure if this is what you are seeking but you could create a starfield like in this tutorial here:

    And then do a sky replacement like in this one here:

    Or, if those are not to your needs, you could try duplicating your footage into a new comp and mask out everything but the sky.  Tweak the color and contrast to darken it down a tad and add a white plane above it and draw (probably very tedious) a series of small masks and blur them to simulate a starfield.  I guess that might work.   There is something niggling at my brain about using an image of stars and the set mask effect also, but I don't know near enough about that to be of any use to you.  I'd have to experiment for days to figure it out.

  • BobDiMarzioBobDiMarzio Website User Posts: 632 Just Starting Out

    I think what @Davlon is inquiring about is the multipoint star effect  one gets when photographing a bright point of light or the sun when shot with an extremely small aperture (F stop).  This is easily accomplished in still photos by using  the Topaz Star Effects plugin.    In days long gone, we would use a physical star filter which is effectively a window screen type grid laminated between glass. 


    I know I did not answer your question about adding this effect in HF, but , I hope this has helped.


  • DavlonDavlon Website User Posts: 283 Just Starting Out

    Bob has it right.

    There has to be some kind of filter for this -- the manual way to do it would be to isolate the bright dots in a picture, copy them to a black layer,  and then apply multiple passes of a motion blur at 30, 60, 90, 120, etc degrees. 

    But I can't figure out an easy way to get the taper effect at the end of the blur...

  • NormanPCNNormanPCN Website User Posts: 3,950 Enthusiast
    edited October 2017

    The light flare effect in Hitfilm can create spiked stars around the flare hotspot. The auto light flares effect will automatically put these where a hotspot goes beyond a certain threshold. The regular flare would need to be tracked. Overall, greater control but a bit more work.

    White rays, spiked star, diffraction spike. Lots of choices but all flares can have rays. It is a separate control. They will just look different. You can turn the "other elements" brightness down to zero to suppress those. You cannot have the rays without the hotspot.

    Anyway, it's all I can think of.

  • tddavistddavis Moderator, Website User Posts: 4,196 Moderator

    @Davlon Oops. Sorry for my blunder.  After reading Bob's post I realized where I misinterpreted.

  • Triem23Triem23 Moderator Moderator, Website User, Ambassador, Imerge Beta Tester, HitFilm Beta Tester Posts: 18,313 Ambassador

    Gleam should do it as well.

    First, duplicate your video layer and add either Threshold or Hotspots filters. Adjust until you've got your lights white and as much as the rest black. Then add your auto flares or gleam. Then set this layer's blend to add. 

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