Adobe After Effects ACP common mistakes
Adobe After Effects ACP · Understand the traps and how to avoid them.
Creates every new composition from the Composition > New Composition defaults (1920×1080, 25/29.97/30 fps) instead of matching the source footage, then animates and renders at a frame rate and duration that do not match the media.
The New Composition dialog opens with the last-used or default preset, and the frame rate and duration fields are easy to skip while concentrating on name and size. The mismatch only surfaces later as stuttering playback, duplicated frames, or an animation that is cut off.
What to do instead
Select the footage in the Project panel and use File > New Comp from Selection so size, pixel aspect ratio, frame rate, and duration are inherited, then confirm them in Composition > Composition Settings. Alternatively, read the Frame Rate column in the Project panel before typing values manually.
Imports a layered Photoshop or Illustrator file with Import As set to Footage, then finds there are no individual layers to animate.
The 'Import As' drop-down remembers the previous choice and often still shows Footage, which flattens the artwork into a single item. Candidates accept the default because the file name and location are the focus of the dialog.
What to do instead
Re-import and set Import As to Composition (or Composition – Retain Layer Sizes), choose the layer-style and merge-footage options deliberately, and delete the flattened footage item so it is not accidentally used later.
Imports an image sequence or a clip with an alpha channel and leaves footage interpretation untouched, so the clip plays at the wrong speed or its transparency renders as a black box.
After Effects guesses frame rate and alpha type from the file. PNG/TIFF sequences default to the project frame rate rather than the capture rate, and straight versus premultiplied alpha is frequently misread.
What to do instead
Right-click the footage item > Interpret Footage > Main, set Assumed Frame Rate to the real capture rate, set Alpha to Straight or Premultiplied to match the source, and only apply pulldown removal when the footage actually carries it.
Selects all keyframes and presses F9 (Easy Ease) across the board, or leaves default Linear interpolation, when the task requires a specific ease in/out, a custom velocity, or a Hold keyframe.
F9 is the shortcut candidates memorize first, but it applies both Easy Ease In and Easy Ease Out to every selected keyframe, wiping out the intended timing and any Hold keys planned for stepped animation.
What to do instead
Select only the relevant keyframes and use Animation > Keyframe Interpolation to set Temporal and Spatial interpolation explicitly. Use Ctrl+click on a keyframe (or Toggle Hold, Ctrl+Alt+H) for stepped values, and refine velocity in the Graph Editor rather than relying on F9.
Scales or rotates a layer without repositioning its anchor point, so the layer swings around an off-centre pivot, or parents layers after animating them and the motion doubles.
The anchor point defaults to the centre of the source, not the visual centre of the artwork, and parenting preserves the child's existing keyframes while stacking the parent's transform on top of them.
What to do instead
Move the anchor with the Pan Behind (Anchor Point) tool, or use Layer > Transform > Center Anchor Point in Layer Content. Parent first and then animate, or delete the child's duplicated transform keyframes after parenting.
Draws a mask with a shape tool selected and ends up with a separate shape layer, or applies a mask to one layer and expects it to hide or reveal the layers below it.
With no layer selected, shape tools create new shape layers rather than masks, and masks only affect the pixels of the layer they belong to, never the rest of the stack.
What to do instead
Select the target layer first and draw masks with the Pen tool (G). To use one layer's silhouette to affect another, set a Track Matte (Alpha or Luma) on the layer above, or pre-compose the layers together, before animating.
Applies effects to an adjustment layer placed below the layers it should affect, or expects an effect to operate after the layer's transform.
Adjustment layers only affect layers beneath them in the same composition, and within a layer the render order is masks, then effects, then transform. An effect on an adjustment layer cannot reach layers above it or pixels inside a pre-comp.
What to do instead
Drag the adjustment layer above its targets, or move the effect onto the individual layers. Re-order effects directly in the Effect Controls panel, and pre-compose (Layer > Pre-compose) when an effect must act on already-transformed pixels.
Animates a text layer's Position and Opacity by hand for per-character reveals, or keyframes the layer transform when the task asks for one specific shape group to move within a shape layer.
Text Animators with Range Selectors and shape-layer Contents groups each carry their own transform and properties, and the layer-level transform is the wrong handle for these tasks, producing the wrong motion and uneditable stacks.
What to do instead
For type, add an Animator (Animate > Position/Scale/Opacity), animate the Range Selector's Start and End, and set Advanced > Shape to Square or Ramp Up for stagger. For shapes, expand Contents and keyframe the group's Transform or the shape's Path instead of the layer's Transform.
Creates a camera or adds 3D lights while layers are still 2D, so nothing responds to the camera, or leaves vector and PSD layers un-collapsed so they pixelate when scaled in 3D.
Whether a camera or light affects a layer depends on that layer's per-layer 3D switch and on the composition's 3D renderer. Continuously rasterized footage only re-renders at full resolution when Collapse Transformations is enabled.
What to do instead
Enable 3D on every layer that must live in 3D space, choose the renderer in Composition Settings (Cinema 4D for extrusion and bevels), drive the camera from a 3D null, and switch on Collapse Transformations for Illustrator and vector layers that get scaled up.
Adds the comp to the Render Queue, accepts the default Best Settings and Lossless output, and delivers a huge uncompressed file, or a file with an unwanted alpha channel, instead of the requested H.264 or ProRes deliverable.
The Render Queue defaults to Lossless, and switches to Lossless with Alpha whenever the comp has transparency. Candidates press Render without opening the Output Module, so codec, channels, and output path are never verified.
What to do instead
Click the Output Module's template name before rendering and set the format and codec explicitly (QuickTime with ProRes 422 HQ, or H.264 through Adobe Media Encoder), set Channels to RGB unless alpha is required, confirm the output path and frame rate, and check Render Settings for Best Quality with motion blur and frame blending enabled as needed.