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How can I key this better?
I need to make only the earphones in this video : https://www.youtube.com/watch?v=3sdpBbrXzb4&feature=youtu.be
glow, while the rest is dark, and so I did some messing around for about an hour trying different things before finding out Andrew Kramer had a very nice tutorial on the subject here https://www.videocopilot.net/blog/2013/10/new-tutorial-tip-selective-glow-fx/
(I didn’t know you could invert channels to do it, I was going a much longer convoluted way involving changing colors and threshold and precomps.)
Here is my best attempt so far: https://www.youtube.com/watch?v=wwnCj221N-c&feature=youtu.be
As you can see, the main piece glows fine and clean, and sometimes the bottom wire too, but I can’t seem to get the wires in there as well. I even tried using Leave Color to isolate only the cyan in the picture, and make the rest B&W, I figured that may reduce keying spill since the color was better defined….but I just can’t get it. The top wires are too blurry at parts, and registering closer to white than blue. Is there a way to…I dunno, turn colors that are close to a color (blue in this case) to that absolute color? Crush the channel blacks or something?
I’m thinking it’s a problem with the video (I downloaded it off youtube, so it’s already highly compressed, maybe would be better if its raw) but I don’t want to blame the video yet, I want to see if there’s something I’m not doing here, based on all of what you guys say.
Thanks
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5 Replies
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I tried a luma key, to drop out a lot of the darks, then 2 keylights to remove the skin and yellow shirt..I lost a little of the cord in the shirt though. But I was just messing around for only 5 minutes. Take a look, maybe this will give you some different ideas. Often with this type of work, you need to use multiple techniques, include some roto work.
You’d also have to do some more masking to remove her now glowing arms…:)
Johnny Cuevas, Editor
Thinkck.com“I have not failed 700 times. I have succeeded in proving that those 700 ways will not work. When I have eliminated the ways that will not work, I will find the way that will work.”
—THOMAS EDISON on inventing the light bulb. -
Hey John, thanks, I hadn’t even tried Luma Key! I didn’t realize what it was til today…I took pieces of your method and pieces of my convoluted method and ended up with a niceish result, see what you think! Also thanks so much for providing a project file with your answer.
Basically now that I knew what a Luma Key was I thought “Well, what can I do to make the blue stand out brighter or darker from everything else?” so I tried decoloring everything but the blue, then boosting the blue, and changing the blue to white, and using that as a matte” you’ll see.
You think that’s the limits of the video? (without rotoscoping, I really don’t want to rotoscope, and this is more an experiment to not rotoscope anyway.)
(…..actually, is there a way to add alpha? Like, paint it on? Like say the effect didn’t cover the whole wire, it missed a few spots in different frames. Instead of masking and rotoscoping the whole wire that way, could I just see those frames and expand the alpha matte in just that frame using paint or something?)
https://www.youtube.com/watch?v=CofhpmPb8-Y&feature=youtu.be
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That’s actually a pretty good way to do it. I did some experimenting and here’s the method I used. Made another copy of the girl and locked the comp viewer. Double-clicked the layer to open the layer viewer. Since there already is a full alpha, I figured, erase and invert. Click the erase brush and in the paint panel for channels, choose RGBA.
Looking in the comp viewer, I went to a frame that needed more glowing cord and erased it, set a keyframe for path and then went to the end of the comp AND DRAGGED the paint layer that’s created in the effect all the way back to the keyframe(wish there was a short cut for this_cause you have to do it for every new erase layer you make). “Page down” and needed to erase some more(the erase layer automatically extended each time I made a new stroke, that was a bonus)—did that until I was good. Went a few more frames, saw I needed to fix more, so I clicked off of the “erase 1” and started the process over. I only did a couple of seconds, but it’s pretty quick and easy to do it this way.
Then I added an invert effect, levels to pop it more(I actually did this last, but it’s third in the layer stack, I saw it needed it after I applied your blur and glow.) then blur and glow. I think it looks pretty good and natural(well natural for a girl dancing with a glowing radio-active iPod).
7307_glowjefftryeraselayer.aep.zip
Johnny Cuevas, Editor
Thinkck.com“I have not failed 700 times. I have succeeded in proving that those 700 ways will not work. When I have eliminated the ways that will not work, I will find the way that will work.”
—THOMAS EDISON on inventing the light bulb. -
Yeah man that looks great! I had no idea you could animate eraser and paint like that (to tween), I just started drawing stroke after stroke and it looked bad. Also, when I did it, I got 100ish different paint stroke layers, when you did it, you got 4. How’d you do that?
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Hey John I’m trying out something with the stroke effect similar to what we’ve done, here
https://forums.creativecow.net/readpost/2/1049627
If this works I’d think it would be a faster, smoother way to paint alpha data.
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