|Tutorial: Image Control Filters in FCP
Oct , 2001
Don't worry. We'll fix it
Image Control Filters in FCP
You've positioned your camera, done your white balance, set your
exposure, checked your Zebra stripes. You shoot and move to the
next location and go through the process again. Different camera
angles, different heights, different locations shooting North
and South. In doors and out. Incandescent, Fluorescent, Photoflood
and Daylight balanced. Too much light, not enough light, hazy
light and harsh light.
Back at your Penthouse editing
suite you sit in front of FCP with your clips on the TL and well,
they don't match up visually. Most are okay but some clips need
Image Control Time
FCP has eight different Image Control
filters in the Effects Browser. A number of these Image Control
filters are the same as filters found in other graphic applications
Brightness and Contrast
The Brightness and Contrast filter is
a very basic but important tool. Used when the video is too light
or dark, too flat or contrasty. When you are lightening an image
using this filter you may find that when you have the correct
lightness but your image looks washed out or flat. Adding contrast
will improved both the highlight and shadow areas of your image
and give it some snap. The Contrast element of this filter changes
both the shadow and highlight areas equally. You can not adjust
one without adjusting the other. If your whites are too hot and
some image detail is lost in black, lowering contrast will pull
some image back from the highlight and shadow areas of the image.
While this filter does not have a lot of finesse it is useful
for getting your image into the ball park where you can use other
Image Control filters to fine tune the image if you need more
When we look at our video images we need
to look at three eleements of of the image. Highlights, Midtones,
and Shadows. When doing color correcting we need to first decided
which of these three areas need correction. It is often true
that not all three need correcting. The video of the Guitar player
below left was shot on stage which was lit with red spotlights.
This may be the effect you are looking for but if you want to
have a more normal color balance than color correcting is needed.
Looking first at the highlight areas,
the white face plate of the guitar, we can see a stronge red
cast. Select the highlight button in the controls and make your
adjustments. Now we want to adjust the midtone section of the
image as well but we have already used the highlight button.
To work on the midtones of the image drop the Color Balance filter
a second time onto your clip and double click the clip in the
TL to load it into the Viewer > Filters tab. We now have two
Color Balance filters and we can select the Midtones button on
the second filter and make the necessary adjustments. If you
need to color correct the shadow areas as well, simply drop the
Color Balance filter on your clip a third time.
The Desaturate filters opens with the
default setting at 100 which produces a Black and White image
from color video. Moving the Amount slider midway to 0 will show
the video uneffected by the filter. Moving the slider further
to the left, negative numbers, will begin to add color saturation
to the video. The Desaturate filter would most often be used
to make a Black and White from color video. As this filter has
only one adjustment, 'Amount', there is no way to further enhance
the Black and White image. I have found that this filter almost
always produces a black and white image that is flat and needs
further correction. Because of this I never use this filter for
converting color video to Black and White. I use the 'Sepia'
filter (below) for making my Black and White images. The Sepia
filter has a second control, 'Highlight', for adjusting contrast.
Desaturate does work if you want to adjust the color saturation
of your video.
The Gamma Correction filter works only
on the midtone section of the image and does not effect either
the highlights or shadow areas of the image. This filter works
by either excluding or including more midtone values in the image.
While the highlights add brilliance to the image and the shadow
areas add depth, it is the midtone range that conveys the visual
information. Changing the values of the midtone area can not
only improve the image but often changes the mood and feeling
of the video as well.
The Levels filter is supposed to be a
more advanced version of the Brightness/Contrast filter, offering
separate controls over highlight, midtone and shadow areas. In
addition this filter offers the choice of working the image in
RGB mode or any one color channel independently, Red, Green or
However this filter is poorly implemented
and is clumsy at best. It has five slider controls; input, Input
Tolerance are used to lighten the image. The Gamma slider controls
the midtone areas and Output and Output Tolerance used to darken
What makes this filter so difficult to
understand and use is the fact that the filter opens with the
default settings of the Input Tolerance and Output Tolerances
sliders set at 100. With these two settings at 100 neither the
Input Slider nor Output sliders work. It is necessary to lower
either the Input or Output Tolerance sliders then start adjusting
the Input or Output sliders. The real problem is that the highlight
and shadow areas have two sliders each for control.
Photoshop has a Levels filter but it
is a different animal. Levels in Photoshop also has a 'Histogram'
which gives a graphic display of all the pixels in the image
based on their brightness values. The 'Histogram' display is
essential to setting levels but the Levels filter in FCP has
To be honest the Levels filter in FCP
does not work for me at all - I just don't get it. The Proc Amp
filter does basically the same thing and works well. If you want
to play with this filter I suggest that you set either Input
or Output to a setting of 20 then start lowering the Tolerance
filter down from 100. As you lower the Tolerance settings more
effect will be applied. If anyone can offer any insight into
this filter I would love to hear about it.
This image control filter comes from
the analog tape days when a 'Processing Amplifer' was used to
do image correcting. With the Proc Amp filter in FCP we can adjust
Black levels, White levels, Chroma (saturation) and Phase (hue)
each independently. Unlike the Brightness/Contrast filter which
works on both shadow and highlight areas together, the power
of this filter is the fact that you can make changes to either
the shadow or highlight areas without effecting the other.
Because this filter has an analog history
the names of the controls are not what we are used to. 'Setup'
could be called 'Black Level' (shadow areas) as it controls the
levels of black in the video, it lightens or darkens the darkest
or black areas of the image. 'Video' could be called 'White Level'
(highlight areas) as it effects the brightness of the whites
in the video and sets how bright the whites will be. 'Chroma'
could be 'Saturation', adjusts the amount or intensity of color
in the video. 'Phase' controls the 'Hue' or overall color of
the video. Moving the dial clockwise, positive numbers, moves
the hue through red, pink, magenta, purple and blue. Moving the
dial counterclockwise, negative numbers, moves the hue through,
red, yellow, green, cyan and blue.
With the Forrest Fire video below all
four elements need correcting. It is important to note that adjustments
need to be made in the proper order. Just follow the order as
the controls appear in the Proc Amp panel, from top to bottom.
You can get some really spectacular looking video using the Phase
The Sepia filter opens with a default
color setting of a warm Sepia which produces Sepia toned Black
and White video, the Amount default is 100. As the Amount slider
is move towards the center, 50, the normal RGB colors start to
appear and the Sepia tint starts to fade. Moving the slider all
the way to the 0 at the left will result in no Sepia effect and
normal video colors.
While this filter defaults to Sepia any
color can be used. Clicking on the Sepia colored square in Controls
will produce a color wheel from which you can select your color.
You can also use the eyedropper to sample a color or set numeric
The Sepia filter offers a nice effect
but I confess to using this filter for making Black and White
video. Clicking on the Sepia square I change the color to Black,
leaving the Amount setting at 100. This produces a Black and
White image not unlike the Desaturate filter. However the Sepia
filter has one additional control. While this control is called
'Highlight' it actually behaves a bit like a contrast filter.
The Highlight control defaults to 0 in the middle of the slider.
Moving the slider to the right brightens the highlight areas,
moving the slider to the left darkens the over all image.
The picture, below left, shows the Sepia
filter at it's default settings. The middle picture is also at
default except that the color Black has been substituted for
Sepia. The picture on the right has had some Highlight added.
With Highlights added the Black and White image now has a sharper
and cleaner look. If you look at the face of the guitar you will
see that the white area now looks whiter. The Sepia filter is
an excellent filter for making Black and White video from colored
video as well as adding a color Tint to the video.
The Tint filter defaults to the color
black with the Amount set to 100, producing Black and White video.
Moving the Amount slider to the mid point of 50 reduces the Black
tint and allows more of the existing video colors to show through.
Moving the slider all the way to the left, 0, removes all Tint
I have changed the tint color from black
to dark blue. The picture, below left, shows the Tint filter
with a dark blue color and an Amount setting of 100. The middle
picture has an Amount setting of 50. For the picture on the far
right I changed the tint color from dark blue to a very pale
light blue. This filter is lacking the Highlight control of the
Sepia filter and for me has little value.
In a perfect world we would not need
Image Control filters unless we wanted to creatively change the
look of our video. Image Control filters are very powerful tools
for creating special looks. Alas, we do not live in a perfect
world so there are going to be times when we'll need to correct;
color balance, hue, brightness, darkness, gamma, and the contrast
of either highlights shadows or both. Don't forget that all of
these filters are keyframeable.
Don't wait until you actually need to
do image correction. Take some time and go through the Image
Control filters that FCP offers. Move the sliders around and
try extreme settings. You will be surprised at what these filters
can do with video. Really surprised!
Thanks to Steve Martin
for the two guitar videos used in this article.
copyright © Ken Stone 2001
This article first appeared on www.kenstone.net and is reprinted here
All screen captures and
textual references are the property and trademark of their creators/owners/publishers.