Busted Flourescent Light Flicker

[Mark Harris]

After Efx gurus, Lend me your ears!

Okay, we had planned on doing this on set, but it just didn't work out.

So I have been using the wiggler to create a kind of flicker effect in post. Like there is a busted flouro light in the bathroom.

But I would like to figure out how to get it focused on the highlight portion of her face. You can see the right side of her face is brighter, where there is a light source. I am looking for some tips for getting it to look like THAT light source in particular is flickering.

I suspect somehow masks are involved, but I just can't wrap my head around it yet.

Any help? Here is the shot. I cannot put up footage because this is from my TimeFest entry. But if you just kick me in the right direction...

http://www.dvxuser6.com/uploaded/2939/1209164367.jpg

Thanks!

[oneinfiniteloop]

You'll need to roto the part of her face that you want flickering and use that mask as a track matte to your flicker layer. You can probably get away from a rough mask with feathering to simulate the falloff, just be careful not to light up the hair on the back of her head that intersects with her face.

[Mark Harris]

Hey, thanks, I have been coming to the same conclusion and am getting some better results with selective masks already.

Just wanted to make sure there wasn't some magic doo-dad I was missing.

[oneinfiniteloop]

You could try a luma key or keylight to dial it in, add some blur, but that depends on your source footage. Looks pretty clean, so might be worth a shot.

[Gary Parkinson]

http://www.dvxuser6.com/uploaded/28910/1209276142.gif


Is this somthing like your after? It took about 10min to do. I duplicated the clip, added a mask around the area, applied softness to the mask about 150, applied an "add" under the blending mode options and just played with the transparency settings. Kept it around 0% to 15% to 20% back to 0% etc

Its a pretty crude animated gif but it looks good trust me.

Using the blending mode "Add" simply brightens the highlighted areas.

[Mark Harris]

Yeah, that's pretty close to what I've gotten. I'm now looking for ways to bring that bright part of her face DOWN in the flicker. If you notice, it's hard to get that part to change at all with the wiggle-flicker. Going to play with the luma key today.

thanks all!

[blckhawk542]

Play with the exposure settings. Set your project in 32 BPC then go to the effects window and look for exposure or levels. Then just set keyframes.

It could work.

[Drew Ott]

In this tutorial, if I remember correctly, there was a way to just apply effects to a certain range of colors (skin in this example).

http://www.videocopilot.net/tutorials.html?id=53

You could use some of what is shown here to get the effect. Instead of smoothing the skin once you have the proper portion selected, just keyframe the exposure.

This could potentially not help at all, it's just worth a shot.

[ProfessorU]

Yes, Drew is close. Rotoing that would be a pain in the butt. See what information you can get from each of the different channels. Chances are you can get an adequate matte from either the red or the blue channel and some work with levels.

[Matt Grunau]

Play with the exposure settings. Set your project in 32 BPC then go to the effects window and look for exposure or levels. Then just set keyframes.

It could work.

I would try this route as well, but on an adjustment layer. Exposure would work, and so would levels, curves, and others.

What would be the best solution would be to use the Extract filter from the Keying section on an Adjustment layer, use it to isolate the highlights avoiding the need for any masking at all, set the blending mode to screen or add or dodge, and use the wiggler on the opacity of the Adjustment layer. Just make sure the wiggler isn't set to smooth, so it will be even more jumpy.

[Mark Harris]

thanks guys. I am trying out a bunch of these ideas. I had some good success with matt's idea with the extract filter. Unfortunately, I cannot get it to work without messing up the color. But I have been working on a lower res JPEG, so tonight am going to try the same on high res AVI.

If all else fails, I just wiggle the opacity :)

[Matt Grunau]

thanks guys. I am trying out a bunch of these ideas. I had some good success with matt's idea with the extract filter. Unfortunately, I cannot get it to work without messing up the color. But I have been working on a lower res JPEG, so tonight am going to try the same on high res AVI.

If all else fails, I just wiggle the opacity :)

If it is messing with the color and you are using a lightening blending mode, desaturate the layer you are using the extract filter from. You will need to precompose so you don't desaturate the main video layer.