LAFCPUG: Effects FAQs
From FAQwiki
How do I get good slow motion?
Probable answers:
A. From Kevin Monahan:
You can get good quality slow motion using the Twixtor Plug-in from Re:Vision in FCP or After Effects. You can do both variable and constant speed effects and the quality is much higher than you see in the stock speed tools in FCP.
B. From Nick Meyers:
I've got a "poor-man's" smooth slo-mo that i do in FCP.
It really only works with 50% speed,
but here it is:
Slow clip to 50%. Double the clip up on itself. Add de-interlace to both layers. Set one to upper, the other to lower. Add the blink filter to the V2 clip, Set to 1 frame on, 1 frame off.
You do need to render a small section and see if you have the right field order, and that can change if you trim the clip.
C. From Graeme Nattress:
You can use Compressor or Shake for their optical flow to get great slomo, similar to Shake. Or if you just need a nice 50% slowmo from interlaced video, my G Map Frames plugin does that well and fast..
D. From Jude Cotter:
Update : Since the release of Motion 3, Final Cut Studio users now have access to the Optical Flow technology originated in Shake. This can give excellent results and is easy to apply. For more information, go to http://www.apple.com/finalcutstudio/tutorials/#tab=fcstudio&tutorial=mov-mottrack. A 'Tracking' tutorial is first, followed by the Retiming tutorial.
Where can I get plug-ins for FCP?
Here is a list of some useful plug-ins for FCP. This is not by any means a complete list, but it makes for a good starting point. Google ‘FCP Plug in’ for more results.
From Jude Cotter
- http://www.automaticduck.com
- http://www.borisfx.com/
- http://www.buena.com/
- http://www.cgm-online.com/eiperle/cgm_e.html
- http://www.chv-plugins.com/index.html
- http://www.digitalfilmtools.com/index2.htm
- http://www.digital-heaven.co.uk/
- http://www.dvgarage.com/
- http://www.fxscript.org
- http://www.genarts.com/download-sapphire-ae-mac.html
- http://homepage.mac.com/tomhenderson/beziermatte/
- http://www.joesfilters.com
- http://www.kafwang.com/EUREKA/EurekaMain.html
- http://www.lyric.com/fcp-plugins/
- http://www.mattias.nu/
- http://www.nattress.com
- http://www.petewarden.com/index.htm
- http://www.pistolerapost.com/tech/2strip.html
- http://www.pluginz.com/default.php?from=rlist&genre=6&category=62&type=2
- http://www.redgiantsoftware.com/
- http://www.revisionfx.com/
- http://www.riverrockstudios.com/riverrock/pages/FCP.html
- http://www.synthetic-ap.com
- http://www.trapcode.com/
Also check Simon Kirbys Lunchtime Cinema which has links to FREE FCP Plugins
How to fake a camera flash
Q. Is there an easy way of simulating a camera flash?
From Jude Cotter
A. Yes. Several ways. The quick, simple and free way is to use a 'dip to colour' dissolve. Once you have applied the default transition to your cut, double click the transition in the timeline to load it into the viewer.
Now change the parameters to 6 frames, and the colour to almost white. It's best not to use absolute white with video. Also, think about adding a sound effect such as a camera click, as this will help 'sell' the effect.
Other things that might help
• You can also download a free 'flash frame' plug-in as part of the Too Much Too Soon donationware pack here:
http://www.mattias.nu/plugins/
• For a more controllable effect, you can buy the Nattress Film Effects set which includes 'G Film Flash' here:
http://www.nattress.com/Products/filmeffects/G_Film_Flash.htm
From Loren Miller:
Determine what *kind* of camera flash.
Older bulb-type flashes take longer and 6 frames is about right. Think RAGING BULL.
Newer strobe-type digital flashes are shorter. Think CSI.
Each flash starts very bright and ramps down in a millisecond as bulb energy fades.
A method using simply FCP:
- Blade out frames for flash effect so your filter won't affect surrounding action. You could even peel this section up above by dragging with Option held. Then remove the blading from the clip below. - Apply Brightness/Contrast filter effect (to the dupe if you've done this). - Open the section in Viewer. - Step in and ramp one or both settngs from full to half strength.
Experiment against the particular action background for best effect-- include a fade UP frame if it adds authenticity.
Sound effect is always critical to a good flash.
Can I do black and white, while one thing stays in colour?
Q. How do I do that effect where everything is in black and white, but one thing stays in colour?
Most likely answer:
From Jude Cotter
This is known as the 'Pleasantville' effect, after the movie 'Pleasantville' which gradually introduced colour over the course of the film.
There is an excellent tutorial for reproducing this effect in FCP here:
How to create the 'Pleasantville' effect in Final Cut Pro
How do I create gunshot muzzle flashes?
Q. How do I create gunshot muzzle flashes?
WARNING: These are easily overblown and badly implemented.
Two general methods: 1) native filter effects, 2) Canned effects free or commercial.
1) Simple flashes in FCP using native effects.
Comments: - Determine the length of the muzzle flash. - For a handgun in daylight, it'll be short, 3-5 frames. Longer at night, 5-7 frames. - For an automatic weapon in daylight, try short bursts, 3 frames, repeated as a series for the length of the discharge. - Lay down the audio spot effect as a good effect guide.
- a) Choose the frame as finger pulls trigger for the effect start and Blade it.
- b) Choose the final frame of the flash to end, and Blade it.
- c) Duplicate the bladed section to just above the original track.
- d) Create the flash mask: apply a 4-point Garbage Mask.
- e) Cluster all 4 points in around front of the muzzle. Pay attention to pointing vector.
- f) Create an "ice cream cone" diamond shape with the thick part at the muzzle.
- g) Apply Brightness/Contrast filter to the bladed flash section. Crank up settings to taste.
- h) Crank up the edge feather.
- i) Adjust to taste, render, review.
Optional- Orange color balance adjustment to flash, especially for nighttime/dim scenes.
2) Canned weapon effects.
Some solutions:
Detonation Films: Excellent FCP-specific tutorial and free flashes.
Motion?
How do I make my video look like film?
Most common, and probably most useful answer:
From Jude Cotter
Buy Nattress' 'Film Effects' filter set. The price is excellent, and the package works extrememly well. You can find it here :
Nattress Film Effects
Other packages you can buy
• The 'Magic Bullet' suite by Red Giant Software
Other things that might help : There is a simple method for producing a 'filmish' look in FCP. While it obviously is not as convincing as any of the products already mentioned, it does come in at the great price of free, for the no-budget filmmaker.
- 1. Duplicate your clip on V2 by holding option and shift while you drag the clip upwards. This will produce a copy of the clip in perfect sync with the footage below it.
- 2. Apply a gaussian blur filter to the clip on V2. Push this effect up quite high, so that everything looks very blurry.
- 3. Right click or control click the V2 clip and from the small popup menu, choose composite mode > Soft light, or Overlay.
- 4. Reduce the opacity of the V2 clip until it is barely visible, and only the soft 'wash' effect remains.
If you want to add dust and scratches, select your clips using In and Out on the timeline, and then go File > Export > Using Quicktime Conversion > Format - Quicktime Movie > Options > Filter > Special Effects > Film Noise. Pull all the options down low so they aren't too cheesy.
There is also the option to change the colour in this menu as well - Faded Film or Faded 1930s, etc.
You can also add grain in the generator menu - Render > Particle Noise with a good blur on it often works well.
Another similar but more basic technique will also produce good film like results.
From Joel Peregrine:
Highlight a clip, duplicate it and place it directly above itself in the same way your technique is set up. Set the V2 opacity at 50%. Now place the "de-interlace" filter (with the "LOWER" setting selected) on the V1 clip. Next, place "de-interlace" (with the "UPPER" setting selected) on the V2 clip. Thats it!!! No interlaced-induced flicker. Full resolution, No strobing, No jaggies, just a subtle, classy, non-video look.
My effects/titles look awful
Q. My effects/titles look terrible once they are on the timeline in Final Cut. They look OK before this. Why?
From Jude Cotter
Most likely answer :
A. There are some fundamental differences between a computer monitor and a television monitor which mean that you cannot accurately judge the quality of things like titles, effects and colour on your computer once they have been prepared for television. For accuracy, you must use a properly calibrated external broadcast monitor. For a rough (non-professional) guide, you can use a TV set.
To connect an external monitor, you can use the output of your deck or camera (computer > firewire > deck / camera > external monitor), or a third party card.
Other things that could help:
• You can also export a QuickTime movie, enable High Quality playback in the QuickTime Player and see it there.
• Or export to tape and play this on a television to check that everything is OK.
Other things that it could be:
• Make sure that your graphics are placed on whole numbers in the motion tab.
• Don’t build your graphics too large. Massively reducing the size of graphics in FCP reduces the quality. Try to stay within two times the size of your format unless you have a special requirement for a big zoom in.
• Make sure you are fully rendered in SAFE RT
Also read "Great Titles with the DV Codec" by Philip Hodgetts
How do I make a telephone voice?
Q. How do I make a voice sound like a bad telephone?
Most likely answer
From Ian Graham,br> The Telephone voice officially goes from about 180 Hz to 3200Hz. I use 300 to 3K. roll off everything else and then tilt the piece in the middle to favor the highs. Add long-distance hishing noises or other disturbances as appropriate.
Use Low shelf. roll off at 350, at a -6 to start.
High shelf at 3500 at -6.
Then find a source of hiss & crackle. I use a 2 min section of phono record I recorded years ago . . .needle just running the inside groove.
Ripple Training has a good tutorial:
PLAYING TELEPHONE WITH FINAL CUT PRO'S BAND PASS FILTER
There is also this tutorial on FCP Producer:
Telephone Voice Sound Effect
How do I make a clip play in reverse?
Q. How do I make a clip play in reverse?
From Jim Perry
Control-click the clip and select "speed...", then click the "reverse" box.
Changing clip speed without changing duration
Q. I want to change the speed of a clip in my timeline but I don't want to change its duration in the timeline. How do I do that?
Most Likely answers:
From Michael Horton
Match Frame is your friend: Read this tutorial over at Ken Stone dot net.
How to get the most out of Match Frame
Don't like to read? Then watch video pod cast #1
(Clip Speed) from Digital Heaven
Or watch this:
Final Cut Pro - Speed Changes with Match Frame (Movie) by Ripple Training
How do I light a Greenscreen?
Q. How do I light a greenscreen so as to get a good key in post production?
Most likely answer:
From Joey "grafixjoe" Morelli:
Also read this excellent tutorial on how to shoot, light and work with your talent in front of a blue or green screen
Greenscreen and Bluescreen Checklist
How do I blur a face or an object like in Cops?
Q. How do I Blur a face or an object so I can hide its identity?
From Michael Horton
Most likely answer and one way to do it:
- 1. Double click the clip to load it into the Viewer
- 2. Duplicate your clip on V2 by holding Option and Shift while you drag the clip upwards. This will produce a copy of the clip in perfect sync with the footage below it.
- 3. Turn off the track visibility light on V1. (makes it easier to see your changes)
- 4. Apply a mask shape filter to the clip on V2. (It's in Effects > Video Filters > Matte > Mask Shape)
- 5. Click the Filters tab at top of viewer. Scale your mask using the vertical and horizontal sliders to fit what you want to mask. You can move the mask shape anywhere on the clip by selecting the cross-hair button next to "Center."
NOTE: if you are masking a face choose OVAL from the Shape pop-up button.
- 6. Apply a Gaussian blur filter to V2. (It's in Effects > Video Filters > Blur > Gaussian Blur.) Adjust the blur to suit your taste by using the Radius slider.
- 7. Turn back on Track visibility light on V1.
- 8. Render
Here is a QT movie by Ripple Training that pretty much describes what is written above:
But how do I mask and track a MOVING object?
From Loren Miller
A Motion Tracker is best, but if you don't have it available, just use a Marker everytime the scene settles-- these instances are the most critical to blur-- and you can simply keyframe your blur mask shape to each marker location. Even if it zooms, mark major changes. Keyframing will interpolate the motion. It's rough and ready but it works.
Motion Trackers/Rotoscoping apps are best and ideal if your clip is long and the object is moving all over the place. Here are a few in no particular order:
- Motion Hey, you bought it and you might as well use it. Has a nice motion tracking feature.
How do I create a widescreen matte?
Q. How do I add a widescreen matte to my footage?
From Ben King
Create a new sequence and drop your timeline into that and apply the widescreen mask. Top Menu: Effects>Video Effects>Matte>Widescreen Right or control click the nested sequence and open it in the viewer, select Filters tab and alter to 1.78:1
or
From Derek Mok
Create a black Color Matte using Generator. Apply a Mask Shape filter (Effects - Video Filters - Matte - Mask Shape) to it, then use the following settings:
- Rectangular
- Horizontal 100
- Vertical [Variable] (If I remember right, 80 will give you a 1.66:1 matte, 75.2 will give you 1.78:1, 72 will give you 1.85:1)
- Invert CHECKED
Now rename the Color Matte to "1.85 Widescreen Matte" and drag it into your Browser. Put that on a video track above your clips and it will matte your whole sequence to around the equivalent of a 1.85 Widescreen Matte letterbox. To temporarily remove it to save rendering time, just select it and press CONTROL-B. It's a lot easier than putting on 100 Widescreen Matte filters, and much more convenient than nesting.
or
From Jude Cotter
Use two identical colour mattes - one at the top and one at the bottom of the picture. Using this method means you can have different colours top and bottom if required.
or
Crop one clip top and bottom to suit, then copy the clip. Next, select the entire timeline (apple a) then use 'paste attributes' (option v) and tick the 'crop' box to apply the crop to all the selected clips in one hit.
and
From Nick Meyers
If you create the same widescreen matte in Photoshop, rendering times are even shorter.
Here's a way to create a wide screen mask in FCP:
Lay up two slugs on V2 and V3, (one at the top of the screen and one at the bottom) then make the V1 clip invisible (select, and control b).
The screen will be black, of course, but you can check that it really is a wide screen mask by switching your canvas to checkerboard background. (no real need to do this, but it's re-assuring, and looks cool).
Now make a freeze frame of this. (Shift N), drag the freeze in to your browser.
It's a widescreen mask!
Once you've made the mask, you can set it to any duration you like just by entering a number in the viewer's duration field.
How do I make my 4:3 footage work in a 16:9 project?
Q. I need to put some 4:3 footage in my widescreen project, but it comes out stretched. What can I do?
From Jude Cotter
Here's a tutorial with several ideas for workarounds.
Faking It : Making 4:3 footage work in 16:9 projects
How do make my video look like a cartoon?
Q. I'd like to make my video look "cartoony" like those Charles Schwab commericals or the movie Scanner Darkly. How do I do that?
Lots of ways:
Ben Balzer posted a QT movie tutorial on how to do this using only FCP 5.1.2. You can find it HERE:
Achieving a Quick and Easy Cartoon Look
Nick Meyers added his thought to this tutorial.-
"One thing I'd add to make it a little bit more "graphic" would be a strobe filter with strobe setting of 2 to make it look like it's animated on twos (2 frames shot of each image)
From Mike Watson
I did this with photoshop a few weeks ago, and then turned the image sequence into a QT movie with QT-Pro. Certainly not the easiest way, but for a :30 commercial, it's only 900 frames -- just set up an action, and automate it.
I followed this tutorial:
Comic Art Effect
And then swiped this action:
Adobe Photoshop Tip: Comic Art Effect -- Photoshop Action
And modified it pretty extensively.
There is a setting in photoshop that will open one image, perform the action, save the image, and open the next image. I think mine only took a few hours. Perfecting the action took days. :-)
From Johan Polhem
Best and easiest way to get good results:
- Import footage into After Effects.
- Export as Filmstrip.
- Open in photoshop.
- Apply filters. (Many many different combos to chosse from)
- Tweak individual frames if necessary.
- Save.
- Import to After Effects.
- Render out.
Nick Meyers then added to Johan's idea.
If that's your bag (baby) then you may be interested in the Cheap-o-Scope
There is also this tutorial from Steve Douglas
Creating that Cartoon Effect
Some Plug-ins you might find helpful:
Graphic Novel Look
ToonIt
How do I get symbols, accents & international characters?
From Ben King
If you want specific characters and/or accents go into:
- System Preferences>(Personal) International>Input Menu
- Then check the Character Palette On
This should give you access to the Character Palette from the Flag in top right corner of the menu bar.
- Simply line up your cursor in the document you wish to add the character to
- Open the character palette and double click the one you require. This should insert it into your document.
You can access some accents via keystrokes too.
Please note that on some keyboards the option key is labeled 'alt'. On a Mac keyboard it's the key between the control key and the 'apple' key at the bottom left of the keyboard. If you can't find an option key on your keyboard, substitute the 'alt' key.
Some of the standard keystrokes for accents/characters are:
- To get an Acute Accent ´ is option+e then the letter eg: á é í ó ú
- To get a Grave Accent ` is option+~(tilde key) eg: à è ì ò ù
- To get an Umlaut or Dieresis ¨ is option+u then the letter eg: ä ë ï ö ü
- To get a Circumflex ^ is option+i the the letter eg: â ê î ô û
- To get a Tilde over letters ~ is option+n the the letter eg: ã õ
- To get a cedilla ç is option+c
- To get ø is option+o
- To get ß is option+s
- To get © is option+g
- To get ® is option+r
- To get å is option+a
- To get a ™ is option+2
From Derek Mok:
- To get a ¡ (Spanish exclamation) is option+1
- To get a ¿ (Spanish question mark) is option+shift+/
- To get a © (copyright symbol) is option+g
From Loren MIller
- Shift-Option-8 = degrees °
- Shift-Option-2 - Euro €
- (at least in some fonts)
From Jude Cotter
To get the apple symbol for tutorials, choose a standard Apple font like helvetica and then use option + shift + k
My effects/titles look terrible once they are on the timeline in Final Cut.
Q. My effects/titles look terrible once they are on the timeline in Final Cut. They look OK before this. Why?
From Jude Cotter
- A. There are some fundamental differences between a computer monitor and a television monitor which mean that you cannot accurately judge the quality of things like titles, effects and colour on your computer once they have been prepared for television. For accuracy, you must use a properly calibrated external broadcast monitor. For a rough (non-professional) guide, you can use a TV set.
To connect an external monitor, you can use the output of your deck or camera (computer > firewire > deck / camera > external monitor), or a third party card.
Other things that could help:
- You can also export a QuickTime movie, enable High Quality playback in the QuickTime Player and see it there.
- Or export to tape and play this on a television to check that everything is OK.
Other things that it could be:
- Make sure that your graphics are placed on whole numbers in the motion tab.
- Don’t build your graphics too large. Massively reducing the size of graphics in FCP reduces the quality. Try to stay within two times the size of your format unless you have a special requirement for a big zoom in.
- Make sure you are fully rendered in SAFE RT
Also read "Great Titles with the DV Codec" by Philip Hodgetts
BORIS : Filters not showing in FCP 5.1 and up
I just upgraded and now my Boris filters are missing in FCP, even though they are installed.
From Jude Cotter
Some Boris products running on FCP 5.1 or OS X.4 (Tiger) require a patch from the Boris website. You can find them here
The Boris CC patch has an additional step required to make the filters visible, and some caveats for use. This is from the Boris CC 5.1. patch readme file. Known Limitations
This software patch includes the following limitations. The engineers at Boris FX are working closely with the Final Cut Pro Engineering team to resolve the issues listed in this section. In the meantime, we recommend that you save your work often, and place the CTI over any clip to which you are applying an effect.
• The first time you launch FCP 5.1 after installing your Boris software, you must turn on Caps Lock while you do so; then, quit FCP and relaunch it with Caps Lock turned off. Otherwise, the filter windows will not appear. If you have already launched FCP 5.1 for the first time with the Caps Lock key up, follow the instructions in the next section, “Deleting the FCP Object Cache.”
• If you apply a filter with the Filters tab open, you must have Caps Lock down and place the CTI over the clip; otherwise the custom controls will be missing and Final Cut Pro may crash.
• If you apply an effect using the Final Cut Pro Effects menu, then delete the effect and apply it to the same clip again, FCP crashes. Once you have deleted a Red effect, put the Caps Lock key down, and then reapply the effect; then resume work with the Caps Lock key up.
• (Caps Lock key Down) When you double click a clip with a filter applied to it, FCP may crash if the Filters tab is open in the FCP Viewer. Keep the Caps Lock key up to prevent this problem.
• (Caps Lock key Up) If you double click a clip with a filter applied, and the clip is not under the CTI and the Filters tab is open in the FCP Viewer, the custom controls may be black. To resolve this problem, quit and relaunch FCP. To prevent the problem, move the CTI over the clip before double clicking.
• If you apply a filter, and the FCP Playhead is not on the clip that the filter is applied to, the custom controls will be blank. To avoid this problem, first move the Playhead to the clip. Quitting FCP and relaunching will also resolve this problem. Note that once a particular effect is missing custom controls, further instances of that effect in a session will also be missing the custom controls.
• If the Final Cut Pro Obj Cache and Final Cut Pro Prof Cache files are deleted or cleared, when a filter is added to a clip, its user interface will not appear. To resolve this problem, follow steps 3 and 4 in the next section, Deleting the FCP Caches.
• If you experience unexplained crashes, follow the instructions in the next section for Deleting the Final Cut Pro Obj Cache and Final Cut Pro Prof Cache files. Be sure to restart FCP twice, once with the Caps Lock key down, and then again with it up, as described in steps 3 and 4.
Keep an eye on the Boris website.
Where can I get plug-ins for FCP?
Here is a list of some useful plug-in pages. This is not a complete list, but a good starting point. Google ‘FCP Plug in’ for more results.
From Jude Cotter
- http://www.automaticduck.com
- http://www.borisfx.com/
- http://www.buena.com/
- http://www.cgm-online.com/eiperle/cgm_e.html
- http://www.chv-plugins.com/index.html
- http://www.digitalfilmtools.com/index2.htm
- http://www.digital-heaven.co.uk/
- http://www.dvgarage.com/
- http://www.fxscript.org
- http://www.genarts.com/download-sapphire-ae-mac.html
- http://homepage.mac.com/tomhenderson/beziermatte/
- http://www.joesfilters.com
- http://www.kafwang.com/EUREKA/EurekaMain.html
- http://www.lyric.com/fcp-plugins/
- http://www.mattias.nu/
- http://www.nattress.com
- http://www.petewarden.com/index.htm
- http://www.pistolerapost.com/tech/2strip.html
- http://www.pluginz.com/default.php?from=rlist&genre=6&category=62&type=2
- http://www.redgiantsoftware.com/
- http://www.revisionfx.com/
- http://www.riverrockstudios.com/riverrock/pages/FCP.html
- http://www.synthetic-ap.com
- http://www.trapcode.com/
Also check Simon Kirbys Lunchtime Cinema which has links to FREE FCP Plugins.
What codec handles Alpha Channels?
Is there a codec that handles an Alpha Channel so I don't have to render every time I bring it into the timeline?
Probable answers:
From Joe Morelli:
No (not software only). Maybe with a specific Capture Card, like Kona or Black Magic might have a built-in key accelerator, but a (software) codec by itself will need to be rendered.
From Kevin Monahan:
I have found that a PICT with Alpha will play in real time. Stills only, though.
From Robert Monaghan
DPX from Glue Tools can handle alpha channels
From Frank Jonen
- JPEG 2000
- Animation
My footage is underexposed
Q. I have some footage which is underexposed. Some things in the frame are almost black. How can I fix this?
From Jude Cotter
A. There are a number of things you can do to improve the brightness of your picture. You can use the three way colour corrector to adjust your blacks, mids and whites, you can use the gamma correction filter, or the brightness and contrast filter, or the levels filter and so on.
Most of these methods will introduce some grain if your footage is very dark. One way around this is to select the clip, hold option and shift and drag the clip upwards to V2. This makes an exact copy and keeps it in perfect sync with the dark clip on V1.
Then select the clip on V2 and right click or control click it to access a small popup menu. In this menu, select composite mode > Add, Screen or Overlay. If this makes your image too bright, reduce the opacity of the V2 clip. If the clip is still too dark, repeat the procedure on V3 and so on as required.
An important thing to note is that computer monitors do not give accurate representations of the gamma and chroma levels of video. The picture in FCP on a computer monitor is quite a bit darker than your picture will appear on a television, so be sure to check your work on a broadcast monitor before making adjustments to brightness or colour.
My footage is overexposed
Q. I have some footage which is overexposed. Some things in the frame are completely white. How can I fix this?
From Jude Cotter
A. It’s probable that your footage is unsalvagable. Overexposed DV is very difficult to work with. Having said that, here are some things that may help a bit.
- Add a ‘Gamma Correction’ filter and try increasing the gamma. Keep in mind that everything in the frame will get darker, unless you use a mask on a copy on a separate layer.
- Investigate the Three Way Colour Correction tool. Using the 'Limit Effects' section (which is in a menu exposed by clicking the small black triangle at the bottom left of the 3 way colour corrector) you can make a mask that includes everything at a single, or several close luminances, and therefore just work with this part of the picture. Check your manual for instructions, or, if you are keen, buy an instructional book or DVD on Colour Correction in FCP.