|
Simulating
a video look with After Effects
by
Márcio
Oliveira
This tutorial is intended to use only the standard version
plugins. The tools that you'll need include After Effects 3.1
Standard or later and Adobe Photoshop or another image editing
software.
Objectives: Our primary goal is to simulate a video look
image, grainy, with a lot of tv interference and color shifting.
Our secondary objective is to have full control over these parameters.
Here we go:
Step 01
Create a new comp and name it "Video Look comp". Import your
footage. Letīs now apply some noise to our image. Remember,
we can vary the amout of noise in time, if we want a more organic
look. Choose Stylize/Noise and set a few keyframes. You can
even "break" the interpolation between keyframes to achieve
abrupt changes. To do this select all keyframes and choose Layer/Toggle
Hold Keyframe or press CRTL + ALT + H (win) or COMMAND + OPTION
+ H (mac). You can also create an adjustment layer and adjust
the layerīs brightness and contrast. Create a new solid and
name it "brightness and contrast". Click on the adujstment layer
switch.
Apply the Brightness and Contrast filter. If youīre using AE4
apply Levels, instead. Make sure the adjustment layer is the
uppermost layer. Select both layers and pre-compose them. Name
the new pre-comp "01 - Levels/noise comp."
Step 02
To create the color shifting we have to duplicate our layer
two times. Now we have three layers. Name them "red" "green"
and "blue."
Now apply Channel/Shift Channels to each one of them. Hereīs
the trick! For the "red" layer set "take green from" and "take
blue from" to full of. Do the same with the other layers.For
"green" let alpha and green unchanged and for "blue" let blue
and alpha unchanged. Set the other options to full off. Change
the modes of all layers to lighten. Now all we need to do is
change the position of the layer(s). Sometimes, changing the
"red" layer is enough. Set a few position keyframes for it.
Donīt forget to convert them to hold keyframes. (we donīt want
keyframe interpolation). Pre-compose these layers into a new
one. Name it "02 - Color Shifting comp" (csc).

Step 03
Now letīs create the tv scan lines (even and odd fields). In
photoshop create a new document. This document must be the same
size of your comp or a little bit larger. Fill the background
with white. Create thin black horizontal lines until you have
an interlaced image. Duplicate this document and invert the
colors of the second one. Save the first file as even and the
second one as odd. In After Effects import these documents as
separate layers. Drag them into the"Video Look comp". Duplicate
the "csc" layer and place the "odd" on top of the first "csc"
layer and "even" on top of the duplicated one. Now we have the
following layer order: (from bottom to up) "csc" - "odd" - "csc*"
- "even". Letīs apply a luma matte for both "csc" and "csc*"
layer. For the first one choose "odd" as luma matte and for
the second one choose "even" as luma matte. Donīt forget to
turn off the visibility for the matte layers. Since you wonīt
edit the matte layers anymore you can lock them. Now apply Distort/Offset
to one of the"csc" layers. Offset the image horizontally to
create a field distortion. If you have created real thin lines
in your PS document, the effect will look nice, otherwise youīre
gonna have to redraw everything you have already done.
Well, part of the effect is done. Select all layers and pre-compose
them. Name the new pre-comp "03 - Final comp".
But the image doesnīt look very interlaced since you moved one
of the scan lines. To repair this you can re-import one of the
scan line layers ("even" or "odd") and place it on top of the
uppermost layer. Change its mode to multiply and set its opacity
value to something between 15 and 30. To increase the contrast
create a new adjustment layer and repeat the first step as described
earlier.
Final Step
If you want to tint the layer, create a new solid and change
its mode to multiply, color or hue. If you decide to apply an
effect donīt forget to pre-compose the layer first.
Considerations
Thatīs it! We have simulated a very realistic video look. If
you need a more professional approach use displacement map and
time displacement (both production bundle plugins).
The first one can be used to shift the scan lines instead of
Offset. And the second one can be used to create image distortions.
You can also apply Gaussian Blur (horizontal) to the "odd" and/or
"even" layers and animate their values. If you have the PB version
of After Effects consider applying Scatter to the "even" and
"odd" layers. To enhance the contrast of a layer you can create
an adjustment layer and apply a filter or create a gray solid
(192,192,192) and change its mode to color burn.
If you donīt have Photoshop you can make the "even" and "odd"
layers inside After Effects.
Create a white comp. Apply a black solid to it and change its
vertical scale until you have a real thin line. Now duplicate
this layer a few (hundred) of times and pre-compose it. You
will waste a lot of time, but what can we do??!!
Click
on the video camera to view the final comp
©Márcio Oliveira Brazil. 2000
multiart@svn.com.br
|