Expressions: Working Smarter in Adobe After Effects

What it actually teaches

Jake Bartlett's course is built around a narrow but well-chosen set of expressions rather than a broad survey. It opens with linear(), which remaps one range of values to another, and spends real time on it: rotating a shape based on its x position, then converting that into a proper linear() call with input and output minimums and maximums. From there it moves into arrays (how position and other multi-value properties are addressed with square-bracket indexing), Expression Controls (Slider, Angle, and Point effects that expose editable values in the Effects panel), variables for cleaning up increasingly dense code, and then wiggle(), random(), seedRandom(), and posterizeTime() for controlled randomness. The back half applies all of it to a single project: a sushi tray that lifts, hovers, wiggles, and rotates back into place, all sourced from four keyframes on one percentage-based slider.

How it's structured

The course follows a deliberate arc: concept, then control, then application. Each expression is introduced in isolation on a simple shape before being folded into the class project, so by the time the sushi tray animation starts, the vocabulary is already familiar. The project section is where the course earns its keep. Watching one animation slider, driven by nothing more than a linear rise from 0 to 100 and back, cascade through position offsets, wiggle-driven hover, and layered turbulent displace textures is a genuinely persuasive demonstration of why expressions matter for professional workflows. The Copy with Property Links and Copy with Relative Property Links segments near the end extend the same idea to layer styles and effects across dozens of layers at once, which is a detail many After Effects users never discover on their own.

Strengths and limits

The course's biggest strength is that it teaches a mental model, not just syntax. The recurring emphasis on treating a null object as a control panel, building sliders for every input rather than hardcoding numbers, is the kind of habit that changes how someone works long after the specific expressions are forgotten. The pacing is also honest about complexity: expressions get visibly harder to read as the project progresses, and the course addresses that directly by introducing variables at the exact point the code becomes unwieldy, rather than front-loading that lesson before it's needed.

Where it falls short is scope. Anyone hoping for a broader catalogue of expressions, loops, time remapping, expression-driven text, or JavaScript fundamentals beyond what's needed for this specific project, will find the course narrower than the topic list suggests. It is also unapologetically project-specific in its second half. Someone who doesn't care about food photography or hover-style animations still has to sit through the sushi tray build to see the techniques land, since the concepts and the project are never fully decoupled. The pacing occasionally accelerates too, particularly once property links and layer styles are introduced, moving faster than the earlier lessons.

For an intermediate After Effects user who has never written an expression, this is a focused, well-sequenced 96 minutes that builds real, transferable habits rather than a grab-bag of tricks.

What you will learn

• ·How to write and structure the linear() expression to remap one property's range of values onto another, including across mismatched units like pixels to degrees
• ·How to build custom UI controls with Expression Controls (Slider, Angle, Point) so expressions can be tweaked without editing code
• ·How to use variables (var) to make long expressions readable and maintainable, including nesting variables inside other variables
• ·How to combine wiggle(), random(), and seedRandom() to create controlled, non-repetitive random motion instead of jittery chaos
• ·How to drive an entire multi-layer animation from a single set of four keyframes using a percentage-based 'animation' slider
• ·How to use Copy with Property Links and Copy with Relative Property Links to control effects and layer styles across many layers from one null object