Advanced Keying Controls in Final Cut Pro X - Part 2

okay even though we currently have a completely automatic key with a strength set to a hundred percent you can still use the color selection tools to attempt to improve the key this key is already quite good but let's see how they work first set the view to Matt to better see the results of your changes now in the chroma wheel change the size of the large pie slice by dragging on either edge of the outer graph if you make the pie slice larger you include more colors to be keyed out which starts to key out our talent if you make the pie slice more narrow you are reducing the colors included in the key potentially increasing the areas that are solid or white in the matte view notice that you can't make the outer graph range smaller than the inner graph in this case our changes have little impact on the mat press command Z a few times to undo the changes notice that you can also drag the black dot at the center of the wheel out to expand the pie slice adding more colors to the key which starts to key out the center of our shot or you can drag it in to make the pie slice smaller removing colors from the key by cutting some of these lower saturation colors out the mat gets thicker introducing some more detail in the hair and the glass however you want to switch to the composite view to make sure that this actually looks better in this case although it adds detail to the hair it also introduces more fringing so let's press command Z a few times to undo that change next to the chroma wheel is a keyframe icon along with the standard menu for working with keyframes so the settings you make to the wheel can be keyframe to change over time below and to the left of the chroma wheel is a small box which indicates the chroma roll-off curve this curve shows how smoothly or sharply the key transitions from key colors to non key colors you change the curve by adjusting the chroma roll-off parameter down here notice how dragging right on the slider increases the curve in the graph it also starts to eat into the hair detail in the mat so let's leave it at zero also below the chroma wheel is the luma graph luma or luminance is the other component of color every pixel in an image can be described in terms of its hue saturation and luminance you've already seen how you can choose the hue and saturation values that are included in the key by using the chroma wheel to select the luminance or brightness values that are included in the key you use the luma graph only the lower handles of the luma graph are available when the graph mode is set to scrub boxes these handles control the edge transparency of the mat the handles can extend outside the bounds of the box because the keyer effect works in floating-point precision to bring the handles into view drag horizontally on the sloping curve since those adjustments make the mat less smooth undo them to adjust the shape of the luma curve without moving the handles use the luma roll-off slider notice that the automatic key set it to 10% if you increase the value it seems to cut back on the mat edges reducing it seems to increase the edge detail it's subtle but it does seem to add more hair detail back so let's leave it at zero next is the fixed video check box which is checked by default when enabled it turns on sub pixel smoothing which can help when keying compressed video codecs if your key looks better with it off then turn it off here the smoothing helps the key so we'll leave it on let's now look at our second scenario adjusting a key that you created using the sample color and edge tools switch back to the composite view as you've seen in the Dyna pep key if you aren't happy with the automatic results you can sample areas of your image to be keyed but first we need to reduce the strength parameter since it's set to 100% which means a hundred percent of the automatic key is being used as you drag down on the slider keep an eye on the chroma wheel you'll see both the outer and inner graphs shrink as you Douce the influence of the automatic key drag it all the way to zero to start with a completely uncanonical color and edge tiles to select them we'll use keyboard shortcuts in the viewer hold down the shift key and drag out a box on the green screen near the talents hair to create the core matte notice how the chroma wheel updates to show your selection add another box near the top right where the green screen is darker note that you could garbage matte out this area rather than trying to add it to the key but in this case adding it to the key actually removes more of the white fringing around the hair now hold down the command key and drag an edge line from inside her hair to outside and then adjust the handles and the midpoint slider to improve the key notice as you adjust it how the chroma wheel and the luma graph are both updating to reflect your changes try adjusting the graph in the chroma wheel to improve the key you'll probably find that it's hard to improve on the job done with the sample color boxes and the edges line try adjusting the luma curve and the Loom will roll off here as well here too it's tough to make them map better let's close the color selection tools there's still some white fringing on the talents hair so let's see how we can address that as we explore the other three advanced controls mat tools spill suppression and light wrap open the mat tools here you have even more control over your map however in practice it can be difficult to improve your mat and easy to make it worse the level sliders let you adjust the contrast of the mat making edges more solid or translucent dragging the black point slider right removes hair detail from our mat and makes it worse let's undo that but dragging the white point slider left seems to bring back some of the lost detail so let's set it to about 0.78 while we're still in the composite view try out the shrink expand soften and erode sliders I find that for this key all they do is make it worse so undo any changes close the mat tools and open spill suppression as opposed to the spill level parameter above which adjusts how much magenta color to add to the mat edges to counteract green spill the spill suppression controls adjust the contrast hue and saturation of the spill color I find the spill contrast tool is great for eliminating fringing that the sampling tools could not drag the white point slider left until the white fringing around the talents hair disappears try adjusting the tint and saturation sliders to see if they improve the skin tone on the talent I find the current settings are best close the spill suppression tools and open the light wrap section light wrap can help a keyed subject blend did more naturally with the background by incorporating some of the background luminance into the edges of the key increase the amount slider all the way then take the intensity down to about 50% and the opacity to about 50% one problem with light rap is that it affects the keyed subject where they meet the frame increase the intensity again to see this more clearly along the bottom of the viewer to fix this you would need to use a similar procedure to what you did with the Dyna pet project duplicate the keyed clip as a connected clip remove the key from the top copy and crop the top copy down to just the area where the subject meets the frame for here let's just reduce the intensity until the edge isn't affected to about 20% close the light wrap section you now have what seems to be a very nicely keyed shot by setting a couple of color and edge samples adjusting the matte contrast and the spill contrast switch back to the matte view you may still have some of the green screen showing in the top right corner to take care of that add the mask effect to the clip use the on-screen controls to adjust the mask increase the feather amount to soften the edges of the matte and then switch back to the composite view you

Channel: Ripple Training

Views: 36,947

Keywords: Final Cut Pro X, Final Cut Pro (Software), OS X (Operating System), Keying, Green Screen, Chroma Key, Mark Spencer, Ripple Training, tutorial, Free Final Cut, Free, FCPX

Id: VAeP7mwYOdw

Length: 9min 42sec (582 seconds)

Published: Wed May 07 2014