What You’ll Learn

Effects amplify the impact of Lumen’s other video synthesis capabilites. In this guide, you’ll learn how to:

  • Use the Transform effect to generate feedback-based visuals
  • Use the Kaleidoscope effect to create geometric shapes
  • Use the Trails effect for light-painting and calming things down

Lumen’s Effects

Lumen has three built-in effects you can use for video processing. They are:

  • Transform: Scales, rotates, and translates entire video frames.
  • Kaleidoscope: A single-knob kaleidoscope that can also rotate video frames.
  • Trails: Uses a framebuffer to recreate the classic video trails effect.

As you remember from the Oscillators guide, the Lumen’s Effects section comes right before the output in the signal path for Lumen’s Default Patch. Let’s expand our architecture diagram here to contain each effect individually:

Lumen Effects Signal Path Diagram

The video signal from the mixer gets routed first to the Transform effect, then to the Kaleidoscope, and finally to the Trails effect. Let’s go through each effect individually and talk about some of the cool things we can do with them!


The transform effect can move, rotate, or scale video frames. Its controls can be found under the “Effects” submodule on the Knobs Panel:

Transform Controls Screenshot


The Offset X Knob and Offset Y Knob control the translation of the video signal. They are bi-polar knobs, meaning all the way to the left will offset the video halfway to the left or down, and to the right will offset halfway right or up. A middle value will produce no offset.

Pro Tip Remember that you can double-click to reset these knobs. In fact, you can do that with all knobs in Lumen, including the Scale and Rotate ones!

The Hall of Mirrors Effect

Let’s do something amazing with the Offset Knobs - we’ll create the Hall of Mirrors feedback effect:

Hall of Mirrors Translation Example

To do this, all you have to do is:

  1. Reset Lumen to the Default Patch (Command+N or File -> New).
  2. Mess with the Mod, Sync, and Frequency knobs until you get something interesting.
  3. Make sure that Oscillator A is in Phase Mod mode (it’s in this mode by default).
  4. Turn the Mod Knob up quite a lot on Oscillator A, but not all the way.
  5. Turn one or both of the Offset Knobs just a little bit.

Now You should see some great feedback artifacts appear like in the GIF above! Try it with the Rotate and Scale controls as well - remember, the effect is more noticeable when the Transform effect is applied judiciously.


Similarly to the Offset and Scale Knobs, the Rotate Knob is bipolar. Pretty straightforward, and the effect looks really good with the Hall of Mirrors patch above!

Keyboard Shortcut If you’d like to snap to multiples of 30° and 45°, hold down Shift while turning the knob. This also works for finding exact Offsets and Scales.


The Scale Knob is bipolar as well. Turning all the way to the right will zoom the video out to 25% magnification, and all the way to the right will zoom the video in to 200%.

Scale Example

Keyboard Shortcut Like all Lumen knobs, hold down Control while turning the Scale knob to select your values more precisely. Control and Shift at the same time will make the knob move exxxxtttttrrrraaaa slowwwwwllllyy.

You’d be missing out if you didn’t try the Hall of Mirrors patch idea described in the Offset section with the Scale knob.


Lumen’s Kaleidoscope (or “K. Scope” for short) is one of the parts of Lumen that we’re the most proud of. It lets you create a lot of video patterns that would be off-limits for traditional hardware video synthesizers, and it’s only got one knob:

Kaleidoscope Knob Screenshot

Unlike most knobs in Lumen, the K. Scope Knob is multi-turn, so you can actually turn it around 16 times before it reaches its end! Each turn both rotates the incoming video signal and increases the number of divisions.

Keyboard Shortcut To snap to exact numbers of divisions, hold down Shift while turning the knob. This works for all other knobs in Lumen too.

Kaleidoscope Example

Creating Geometric Shapes

Did you know? You can make shapes like circles, squares, triangles, and pentagons with the Kaleidoscope and one Oscillator in Key Mod mode. This comes in really handy when you start patching, but is still pretty cool even without that. Here’s the basic setup:

  1. Create a new Default Patch by pressing Command+N or selecting File -> New.
  2. Only show one Oscillator by turning the Mix Level down on the other two.
  3. Horizontally Sync that Oscillator by turning the Sync knob up to its middle position.
  4. Make sure the frequency is around 60hz (the default).
  5. Put that Oscillator in Key Mod mode by clicking the button that says “Phase”.
  6. Adjust the K. Scope knob to a specific value, listed below. Remember that you can hold down Shift to snap exact values and Control to fine-tune your setting.
  7. Adjust the Threshold of the Oscillator (where the Wave Shape knob usually is) to get the shape you want. If you increase the frequency, you’ll create concentric shapes, which is cool too!

Square: Kaleidoscope at 2.25

Screenshot showing how to make a circle

Triangle: Kaleidoscope at 3.5

Screenshot showing how to make a square

Circle: Kaleidoscope at about 14.45

Screenshot showing how to make a square


The Trails effect is another point of pride here at Paracosm HQ. Similar to the K.Scope, it’s only got one knob:

Trails Knob Screenshot

Turned all the way counterclockwise, the effect is not active. When you turn it clockwise, it combines the brightest parts of the current video frame and the previous one. It’s easiest to demonstrate with an example that uses the camera:

Light Painting Example

In this example, I’ve got trails turned up to about 80%, and am using the light reflecting off of my ring to do light painting!

The higher you turn up the Trails effect, the more time it takes the “trails” created by the bright parts of the video to fade away. Note that if you turn up trails to 100%, they won’t ever fade.

Science Time The trails effect works because we have implemented a framebuffer, which can store one complete video image. Each time a new video frame is generated, we save it in there. The trails effect uses this to combine the current frame with the previous one, by taking the maximum value of the two frames (per component) and outputting it. Of course, because this generated frame will be stored back in the framebuffer, this creates another type of feedback - feedback over time. FEEDBACK IS EVERYWHERE.

Calming Down Motion

Another handy use of the Trails effect (even when you’re not using the camera) is to calm down patches that have a lot of motion or flickering. Here’s a Hall of Mirrors patch that is a bit too flickery:

A patch that needs to be calmed down

Here’s the same patch after turning up the Trails:

That same patch calmed down with the Trails effect

It’s a bit tough to tell from the GIF, but it’s much better!

Nicely Done

Thanks for taking the time to dive into Lumen’s Effects. Next up we’re going to learn all about External Signal Processing, including how to create mind-expanding feedback effects using an external webcam. If you’re just too ambitious to bother with that now, feel free to skip ahead to the first Patch Panel guide, where the true power of Lumen awaits you.