Lens Flare on Alpha Channel

[Simon Bonner]

So you just want the lens flare with no background, so you can drop it over a cut?

Apply the lens flare to a black solid and set the transfer mode to screen. Render. Then import the footage and add to your final comp and set it’s transfer mode to screen. This will get rid of the black pixels, making it look like you have rendered with a alpha channel.

Someone might have an idea of how you can render a lens flare without the bg colour, but this method works fine.

Simon Bonner

youtube.com/simonsaysfx

[Chris Wright]

You can use the free Unmult from

https://www.redgiantsoftware.com/downloads/archive-versions/#knoll-light-factory-unmult

then you can do cool things like make the flare create a special cross dissolve with it set to stencil alpha.

[David Bogie]

UNMULT totally rocks. Why it’s never been incorporated into AE is beyond me.
I’ve never tried this but I’m sure there must be a simple way to use Set Channel or Set Matte to pull the luma information form one layer and use it to create an alpha.

bogiesan

[Chris Wright]

Here’s a free flare wipe.aep you can monkey around with. It uses a flare to create a silhouette alpha that transition wipes 2 pictures back and forth. It’s subtle and beautiful. Works in cs3. Just replace the two pics/footage with your own.

https://www.megaupload.com/?d=6JINJEBA

[Darby Edelen]

You can do this in AE by creating your lens flare on a black solid, pre-composing the lens flare, then applying the ‘Set Matte’ effect to the pre-comp and changing its blend mode to Luminescent Premultiply.

If you don’t change the blend mode to Luminescent Premultiply then your black background will be incorrectly multiplied into your image.

The downside of this technique is that you need to go into the pre-comp to animate the lens flare.

Darby Edelen

[Chris Wright]

Can this wipe 2 pictures like a vertical wipe transition? I’m trying to figure out your final output. lol.

[Kirk Tabalotny]

“You can do this in AE by creating your lens flare on a black solid, pre-composing the lens flare, then applying the ‘Set Matte’ effect to the pre-comp and changing its blend mode to Luminescent Premultiply.

If you don’t change the blend mode to Luminescent Premultiply then your black background will be incorrectly multiplied into your image.”

Darby – is this going to be the only option available as an alternative to Knoll Unmult, for Vista/XP 64bit users? (apart from dual-boot 32 bit+64 bit OS set-ups). Pity Unmult got archived before 64 bit systems became viable.
Kirk

[Jim Goertzen]

Darby,

Almost two years after posting, your advice saved my butt! I work for a large national broadcaster who has set ‘administrative log-in’ privileges on my computer OS, preventing me from being able to install the UNmult (or any) plug-in. To have someone ‘authorize’ this simple plug-in installation would have likely have caused days of delay. Your solution saved the day!

Thanks!!
Jim

[Junior Lopez]

Thank you so much!!! I knew there had to be a way to do it.