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In trouble with chroma keying - Again! Advice please
- retepnikrap
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So this is the problem as the face painters arms move they cast small shadows on the back of the chair and the problem I have is that when I key out all of the chair back I am losing detail in the face painters arms. Tried tweaking all of the settings in keyer but can't get a balance that works. Is there a way to select or mask off an area and apply different settings? The default keyer settings work almost perfectly when applied, just the chair back that gives me a problem. Any help advice would be appreciated. Thanks
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- retepnikrap
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- Karsten Schlüter
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and, for a start, sorry for asking perhaps the obvious: you are aware of the sample tool in FCPX keyer?
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- retepnikrap
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- Karsten Schlüter
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(note2myself: no coffee while opening new post…)
hmmm, I tried with a grab of your grab, which can only give a vague, close result but:
I took 3 samples, and tweaked a bit with soften and fills…
plus It depends very much on the background.
Strange: there's spill/reflection under his chin …??
And: the artists arm is tricky, little the chair …
missed your 2nd pic by the minute - can you upload the plain bg, just for testing?
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- retepnikrap
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- Karsten Schlüter
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Soooo, two options:
What I've done here, is simply using 3 samples and tweaking with some settings (fill holes, soften, wider) - chair no problem, but the spill on the arm isn't nice/have to soften the key = no 'sharp' pic
Plan
your idea: hold alt-key and drag the clip in the timeline=that doubles it
the top one gets cropped…
that way you create two 'zones' with two diff. keyers:
… in mask mode we see the whole drama: very little separation…
But,FCPX is keyer is for tinkerers like us!
I drag ONE sample box onto it, and most of the damage is gone.
ok, 'fill holes' to get rid of that spot under Jack Sparrow Jr. chin … but not too bad.
You probably have to adjust the key while the action takes place.
The RippleTwins™ offer a free tutorial 'Keying compressed video) (sort-of) on youtube, …
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- retepnikrap
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retepnikrap wrote: …you can see the bad chair back on the lower clip. I must be not fully understanding the process or doing something wrong.
No, I'm so stupid LOL!
For sure, when you key the top layer, the next layer = bad keyed chair gets visible:
Asks to 'punch a hole' in the lower layer:
… applied a mask, invert it, and then, hopefully, finally, we get this going… :silly:
I suggest anyhow the first method, with 3 or more color-samples …
The tricky part is anyhow: Jack and the painter have both many 'green spill' on their skin… I'm used to 'bad green screen', I frequently claim, our school has the worse green screens ever… so, I'm used to tweak with the settings.
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- Karsten Schlüter
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retepnikrap wrote: …Creating the mask has left a key line around the masked area,…
ahh that nasty bug! I remember…
Thought the fix is/was changing the 'staple' order of effects in the Inspector -not so
OK, last try (I'm stubborn to recommend the 3-4 sample method! LOL)
What I did here:
Applied a Shape mask to clip#1, set its Feather to 0 = creates a 'hole' in the clip
Then doubled the clip, invert the mask
Applied to both clips a keyer, with diff. settings (btw: the Spill Surpression is the culprit for colour changes) aka samples)
Finally, I 'feathered' the mask a bit inwards … looks promising
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- retepnikrap
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Drag video clip to timeline, dragged the background image to timeline under video clip. Made a mask around chair back on video clip, pressed 'alt' and duplicated the masked video clip above the original masked video clip. I then inverted the mask on the top video clip. I then applied the keyer to both video clips, adjusted etc.
I have the offending keyline around the masked area, I tried adjusting the feather, both ways on both video clips as you suggest but can't hide, reduce or remove the offending keyline. Is this the process you suggested or have I missed out something? Thank you
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- Karsten Schlüter
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retepnikrap wrote: … have I missed out something?
I missed some points in my description:
in the lower track, I set the Feather to 0
and I dragged the Keyer over the Mask in the Inspector
then…
doubled track, invert Mask, Feather just a tine bit, -0.4
Adjusted the Keyer by 2,3 samples, fill holes, soften - no Spill correction:
aside the terrible banding (due to jpg, compression, et al), outcome fulfill my hobbyists needs ...
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- retepnikrap
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Well, I followed your instructions letter by letter and I just can't get rid of that keyline, tried everything and pretty much every combination of settings as well as yours and still there.
I am going to try and find some 3rd party mask plugins and try that, if that fails will have to re shoot which I was trying desperately to avoid. Thank you again.
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- Karsten Schlüter
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retepnikrap wrote: … can't get rid of that keyline, …
I am going to try and find some 3rd party mask plugins and try that, if that fails will have to re shoot which I was trying desperately to avoid. Thank you again.
sorry to hear that and of being of no help.
Just as a last word: that 'line' problem is house-made by yourself (kinda
I would spend more time on adjusting & tweaking the settings of ONE keyer on one clip… as seen in all my grabs, the chair is less a problem than the arm (and a bit on the left face of Cpt Sparrow Jr.) . The spill from the green bg is way too much = more distance.
I don't see how it looks like on playback… but you can, for example, add diff. sample-boxes for diff. timestamps...
'softening' the key gives acceptable results - imho.
Keep in mind: the focus of your audience is on the face-painting, not on the artists tattoos…
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Thank you
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