After Effects (AE) CS6 for Video Editors Workshop Notes

Information in this guide on specific effect parameters is taken more or less directly from articles in the Adobe Help Menu. Use this resource! Search with specific terms for detailed results.

A note about Dynamic Linking for Premiere Editors

In this workshop we focus on importing and working uniquely in After Effects, but using dynamic linking you can work without having to render out of Premiere and After Effects. It is more efficient. If you are working in Adobe Premiere and wish to apply effects or composite video clips using After Effects (AE), select a clip or a stack of clips in a Premiere sequence and then right (control) click and choose Replace with After Effects Composition. After Effects will open with a composition automatically created. Thereafter Premiere will be linking to an AE project. If you move the AE project on your hard drive you will have to relink.

Changes made in After Effects will update automatically to the sequence in Premiere. If the composition is complex or if the clip will change duration because of a speed change create a unique sequence in Premiere for the clips to be dynamically linked. Afterwards you can copy and paste the clip into another Premiere sequence.

Setting Up in After Effects

Preferences: Preferences/General: levels of undo Preferences/Import/Sequence Footage: use for determining the frame rate of imported image sequences Pref/ Media and Disk Cache: Disk Cache is where RAM previews are stored. AE now caches RAM previews when you close the project. Prefs/Auto-Save: a good idea to turn this on (File/Revert: this reverts to the last autosaved version. There is also a history window: Edit/History)

Preferences/Memory: by default a quarter of your memory is allocated to other applications. If you have 16 GB of RAM, AE should be using 12 GB. With more RAM, AE can preview more video in real time. Project Settings File/ Project Settings:

Time Display: use Timecode for video comps. Command Clicking the timecode reader in the Composition window will also change from Timecode to feet and frames, etc. Color Settings: always 16 bits per channel, never use 8 bit, for color correction or video chroma keying use 32 bit. This setting is also at the bottom of the project window.

Working Space: AE has color management so your files will look identical on display devices that accurately reproduce that color space. For HD video the common color working space is HDTV (Rec.709). AE performs color space conversions on any footage or file not matching that profile. If you Interpret footage on any item you can see the color profile of the file. (Interpret footage button at the bottom of the project window).

Making a Composition (comp.):

A composition is a timeline or sequence. It is short. In AE we always work with one video clip at a time or a very short series of clips. Composition/New Composition (Command N):

Use the HDTV presets for HD video material. Other method to make a comp: right click on your footage(video clip): New Comp From Selection Importing As simple as File/Import

Importing an Image Sequence

AE creates a video file out of any imported image sequence. The image size will be the same size as the original photos. Before importing go to Preferences/Import and determine the Sequence Footage rate. Remember 24p in the NTSC world should be entered as 23.976 fps and 30p will be 29.97 fps. Then File/Import the image sequence by selecting the first image of the hundreds or thousands in your folder. The dialog box will recognize that it is an image sequence. After Effects will recognize image sequences that have broken numbering and you can also import at any frame rate you specify.

Working with Proxies In some comps in the workshop we are working with Proxies. These are smaller size video files that speed up RAM preview times. Although proxy files are smaller than the original footage, AE recalculates all key framing parameters correctly when replacing with the original footage. This is very convenient when working with less powerful computers. You will know when a proxy is enabled by looking at the footage layer and it is also indicated in the Project window. To make a proxy file, simply right click on the any footage in the Project window and Create Proxy/Movie. Save the file on your drive since After Effects will now link to this media as well as your original source.

In the examples that follow, the number and letter refer to the comps in the workshop project.

Part One: Basic Keyframing:

01 A Keyframes

Simple Keyframing: animating position and scale Show Transform parameters below footage in comp. Turn on the stopwatch icon to keyframe the position parameter. Turning off the stopwatch will delete all your keyframes. Keyframes are made automatically when you move the object in the comp window. To see the motion path keyframes of the object make sure Position is selected in the comp. There is a Keyframe navigator to move from one keyframe to another.

Hold down Shift when doing scale adjustments of objects to maintain proportion. Use the Easy In and Easy Out keyframe options to change speed going into and out of a keyframe.

RAM Preview Playback is in real time only with the RAM Preview (use work area to establish preview). The RAM preview playback is the button on the far right of the Preview window. RAM Preview options: use AUTO resolution and From Current Time The Frame Rate should match your comp. frame rate.

01 B Refining Keyframes Preferences/Display/Motion Path – options for how many keyframes to display in comp window Selection Tool (V), Pen Tool (G) Holding down option when selecting the Pen Tool in the toolbar will scroll through all the available pen tools. The convert vertex pen tool is used to square off or add handles to existing keyframes.

Keyframes can be group selected in the comp. or comp. window and deleted.

Frame Blending and Motion Blur:

If desired, turn on frame blending in the comp timeline and on the layer. Frame blending should always be used when the clip is slowed down. Motion Blur will appear when the object is moving quickly.

01 C Motion sketch

Window/Motion Sketch: Start Capture An amusing effect but really useful?

Part Two: Speed Effects Method One: Using Interpret footage

All video slow motion speed adjustments are problematic because the computer must invent frames, new moments in time. The only way to ensure smooth slow motion video is to shoot at a higher frame rate (60p frame rate is available in many cameras) and then ask software like AE or Premiere to play it back at a slower frame rate. Import the 60p video into AE and then go to: File/Interpret footage/Main/Frame Rate/Conform to frame rate. AE will let you conform to any frame rate, even non-standard video frame rates. But usually you will want to conform the 60 fps clip (actually running at the NTSC speed of 59.94 fps) to either 23.976 fps (NTSC 24p) or 29.97 fps (NTSC 30p). The conforming simply plays back the clip at a slower rate. There will be no problematic interpolation or frame blending, no invented frames.

Method Two: the Timewarp effect

Make Sure to Loop the Clip An important consideration when using the “timewarp” effect: if you will be slowing down the video you must loop the clip in order to see the entire clip slowed down and also make sure that your composition is long enough to compensate for the increased length of the clip. The easiest way to do this: before you create the comp.: right click on the footage in the Project window and Interpret Footage/Main. In Other Options you can loop the clip the appropriate number of times. Then create a comp. from the clip and apply your timewarp effect. 02 A Timewarp Speed controls If you didn’t shoot at 60p and want to do a software speed effect on your video, then the “timewarp” effect in AE is the most sophisticated of the software speed tools. However, when attempting to change motion it will sometimes simply not work. The usual problem is that the background will not separate properly from the foreground object in motion. This happens when the clip is slowed down considerably. The background distorts as if pulled along by the foreground object. Usually this problem cannot be corrected. Try to slow down the clip by a lesser amount.

Apply the Timewarp effect to clip on comp. Expand parameters.

Choose the method for frame blending in the Timewarp parameters. You have three choices. Pixel Motion is the preferred method. If the clip has a lot of motion blur use Frame Mix. Whole Frames Duplicates the last frame shown. Frame Mix Creates a new frame by blending existing frames. Pixel Motion Creates a new frame by analyzing the pixel movement in nearby frames and creating motion vectors. Motion vectors represent the movement of a pixel or block of pixels from one frame to the next. Images between frames are interpolated using these vectors.

In Effect Parameters, choose Adjust time by Speed. Turn on keyframe stopwatch for Speed.

Make keyframe adjustments. Negative numbers are reverse motion. Use the Easy In and Easy Out keyframe options to change speed going into and out of a keyframe.

Use the Graph Editor view on the comp. to manipulate the transitions between speeds. This is an icon in the composition tool bar that toggles the comp. view between the linear keyframe parameters to a graph. Smooth keyframes with the Bezier curves.

If motion blur is needed, there are detailed motion blur settings in the Timewarp effect parameters. This is better than simply turning on motion blur for the layer. 02 B Timewarp Source Frame controls

Another method for using the timewarp effect is to Adjust time by Source Frames. This is a useful method for freeze frame effects. Unfortunately there is a limit on how many frames can be counted. Your clip cannot exceed 5000 frames. For a 24p clip this translates into a less than 3 and a half minutes. See comp 02 C Freeze Frame.

Adjusting by Source Frames indicates which frame of the clip you want to appear at which specific time in the comp. Display Frames not time code information in comp window. Use the Layer Window to find the frame you want, then return to comp. In the Layer Window you have View options. Choose NONE to see the layer without the timewarp effect applied. Type in the frame at the specific time.

Look in the AE help menu for specifics about each of the parameters of the timewarp tool. There is a lot of depth to AE, so if the presets in any effect are not working, do some research and experiment.

Adding Motion Blur

There is a default motion blur parameter on the layer in AE. Motion blur simulates the effect of a fast moving object in front of a slower camera shutter. Turn on the box beneath the motion blur icon in the AE comp. timeline. The timewarp effect has it’s own motion blur options if you want to get more specific.

Part Three: Keying Chroma Keying Using Keylight in After Effects (AE) Creating a Mask

03 A mask for keying The first step to keying involves removing any background area with a mask. The less background you have to key out, the easier the task of keying. Sometimes the mask will have to be animated.

Drawing/ adjusting and keyframing a mask: In the comp select the layer that you will be applying the mask to. Use the pen tool to draw the mask onto the layer. The mask will appear below the layer in the comp window. Select the mask layer to see it in the comp window. With RotoBezier selected in the tool bar, the mask will automatically be rounded. Without RotoBezier the mask will be a polygon. Individual mask points can be made round with the Convert Vertex tool (under the pen tool in the tool bar). Holding down the space bar when selecting a point allows you to move a mask point while adjusting the curve. Otherwise you are just adjusting the curve angle. Individual points on the mask can be selected and moved. A single click on one point in the mask will allow you to change the position of that single point. Double clicking on a single point in the mask gives you a bounding box. This allows you to animate or change dimensions on any side of the mask or move the entire mask. Animating a Mask

To animate a mask over time, go to the Mask properties in the comp timeline. Place your playhead at the beginning of the timeline, turn on the stopwatch for Mask Path, and a keyframe is automatically created at the start of your timeline. Move the playhead to where you want to adjust the mask and then move the point or many points of the mask. A new keyframe will be created, etc. Mask points can be adjusted with the selector tool or the pen tool. Turning off the stopwatch will delete all your keyframes for the Mask Path parameter. You can individually delete keyframes or select several at once and delete them. Feathering a Mask Masks can also be feathered but it is not necessary to feather them when keying.

03 B keylight and 03 C wide shot keylight Applying the Keylight Effect

Search for keylight in the Effects and Presets window. Apply it to the layer in the comp timeline that you will be keying. The Effects Parameters are underneath the Effect in the Timeline but also in the Effect Controls window in the top left of the interface. Use the Effect Control window.

Keylight Effect Controls

According to the manual Keylight does two things: “it removes the screen color (blue or green screen) to despill the image and generates an alpha (Screen Matte) to composite the foreground over the background layer.” As we are working remember that any control in the effect can be reset by right clicking on the name of the control and selecting ‘reset”.

Step One: Screen Colour

Screen Colour: select the color to key out with the eyedropper. Choose a darker area of the green screen if the lighting is uneven. You have one choice. Picking a new color overrides the previous selection.

View: switch to screen matte to see the how the matte is progressing The matte should be perfectly high contrast. White is your foreground that will remain untouched. Black is the background that is removed. Gray areas are partly opaque, so partly removed (you don’t want any gray areas unless it is hair or some other wispy substance or something semi-transparent). Gray areas may also appear around the edge of your foreground especially if there is motion blur in the source. This may not be a problem. Use the screen matte as your guide but it is what you see in Final Result that counts. Other View options of interest: Status is another option for seeing the matte. This creates an exaggerated view of the matte so that problems are more apparent. Green areas in the Status window are a warning. Areas that are green may not key correctly. Colour Correction Edges: this allows you to see the matte areas that will be corrected by the Edge Colour Correction Controls

Step Two: Despill Bias and Alpha Bias

The Keylight manual suggests that you use the Despill Bias and Alpha Bias right after selecting your screen color. I find them not always useful. Only consider using these controls if you have spill from your background. Despill Bias and Alpha Bias helps you to get a clean matte when there is spill (reflection of the background color –green or blue) on the foreground person or object. For example if the figure is a person, sample an area of well lit skin tone with the despill bias eyedropper. Be aware that the image may become grainer. If so, avoid this feature and use the separate spill suppression parameters further down after you have gone through step three.

Step Three: Screen Matte Controls

It is very unlikely that you will not have to refine the matte. To do this go to: the Screen Matte Controls.

The Screen Matte Controls can help you refine the key by increasing the contrast in the matte. For example by increasing the Clip White setting you will solidify the interior matte within the foreground figure. Clip Black will remove areas of unwanted foreground from the background. These two controls adjust the white and black point, increasing contrast as you change the threshold of what becomes pure black or white. Clip Rollback will then prevent the “bloom” on the edges of the matte or bring back areas around the edges of the matte, like hair or motion blur. In addition you have softness controls if the matte is jagged. Screen Softness blurs the matte after the key has been pulled. The Despot controls remove isolated pixels of black or white from the matte. Replace Method: these controls add back screen color if you have eroded the matte. Select the background color as your replace color and you will see that this color is added back into the foreground image using the method of your choice (hard or soft). It is unlikely that you will use this feature.

Step Four: Other Options if the Screen Matte Controls are not working:

Screen Gain and Screen Balance Other controls that function very much like Clip White and Clip Black are the Screen Gain Controls. These controls are more aggressive and represent a second choice. Screen Gain: Controls how much of the screen color is removed to make the matte. Increasing the value will key out more background color. Increasing it too much will start to key out areas of your foreground. Screen Balance: controls the hue to be keyed or how pure that hue is.

Change View back to Final Result to see how the key is progressing. At this point it may be useful to put in your background. Screen Pre-Blur: apparently helps with noise problems on Mini DV video clips. Screen Softness in Screen Matte controls seems better. But why are you trying to key Mini DV video anyway?

Inside and Outside Mask Controls

When you create a mask with AE you can choose to use it in Keylight. Outside and Inside refers to what will be made transparent. If you choose to use the Mask in Keylight then the composite mode on the mask in the AE comp must be “None”. Normally it is “Add”. Inside the Keylight controls for the masks a color can be removed using hard or soft light.

Step Five: Foreground or Edge Color Correction in Keylight can be used to clean up spill from the green screen. Reflected green light on your foreground figure may be noticeable even after you have a good matte. If there is a noticeable tint in your foreground from your green screen you can use the Color Suppression controls. The other controls will help you to match your foreground to the new “keyed in” background. You don’t have to use these color controls. They are fairly basic. You can do a better job of correcting color by adding the separate Curves effect after Keylight.

Part Four: Warp Stabilizer

Apply the effect to the clip on the comp. The same Warp Stabilizer effect is found in Premiere as well. The basic option under Stabilization, Result is to smooth the unwanted motion or to have no motion (as if the camera was on a tripod). No Motion is not an option if the video has too much movement, you will get an error message. If other effects are applied to the clip before stabilizing, then PRECOMP the clip into another composition and apply the warp stabilizer to the precomp. Precomping is exactly as it sounds: place one comp into another.

The Warp Stabilizer also has “Rolling Shutter Ripple” correction under the Advanced parameters. Don’t expect miracles. Part Five Tracking Tracking an Object in Motion

05 A Tracking Target Track Tracking involves plotting the movement of an object on one layer and then applying these coordinates to another layer. In this first comp we must have two things to start with: the layer to be tracked and the layer to which the tracking information will be applied. Open the Window/Tracker In the Comp highlight the layer you are tracking.

In the Tracker Window: in Motion Source select the layer. This will open the layer window in front of the comp window. Tracking is performed in this layer window. Select Track Motion in the Tracker window.

Current Track is the name of the tracker (you can have multiple trackers on one layer)

Track type specifies what type of tracker this is. Transform is the basic motion tracker.

Motion Target is the layer onto which the tracking information will be applied. It will automatically select the layer above the layer you are tracking.

On the layer that you are tracking, define the object to be tracked. There is a small box inside a larger box. The small box identifies the object. It should be a distinct object (high contrast is good). The larger box is the search region. If the object moves out of the search region it can no longer be tracked. The cross hairs designates how that tracking information will be applied to the other layer. If you wish you can “offset” the track with this information. Put the playhead at the start and then analyze forward. If the tracking is lost at some point, you can erase keyframes, adjust your tracker, and then continue to analyze forward. Keyframes can also be individually adjusted. When satisfied, Apply the tracking information to the appropriate target layer (the Apply button in the tracking window). You can apply X and Y coordinates information.

Corner Pin Tracking

05 B Tracker Corner Pin

A Corner Pin tracker is a different selection in the Track Type part of the Tracker window. Instead of having one track point to track an object, you will have four track points. This is ideally suited to placing a four-sided object into a moving image. The process is the same as described above. 05 B Tracker Corner Pin continued

In the example I give, the frame in which I am placing my image starts to move off camera. When this happens the matte must be moved by hand. Keyframes must be generated manually for the remaining part of the clip. 05 D Corner Pin offset

In this example, you can see that the tracking points can be offset. This means that the information about the movement of the frame can come from coordinates different than those into which the target layer will be placed. Part Six Color Finesse

Color Finesse is a professional color grading tool. Like the time warp tool it is a plug- in from another company that has been purchased by Adobe. Apply the Color Finesse effect to the layer and when you open it, make sure to type in the name of Concordia University to initialize it. You do not need to register. When working with color finesse, make sure that you have defined a color working space in the After Effects Project Settings. For NTSC HD video choose HDTV (Rec. 709) as your Working Space.

This also needs to be set in the Color Finesse Preferences/Video System/Video Color System/HD 720/1080 ITU.R BT.709. SD video is 601. The window I use the most is the CURVES. Checkmark the Curves option to see the changes that you make. Although the controls in Color Finesse are simple the results are very subtle in comparison with the Three Way Color Correction tool in Premiere. The other window I use is Secondary color correction. Secondary isolates a specific color to correct. The left side of the window is where you define the color be changed. The right side with the color wheel is where you make your color adjustment. Because it is unusual for a color to be completely isolated in a video frame, it helps to make a mask on a layer that you applying secondary color correction to and then adding the duplicated unmasked clip underneath.