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Lenses, Corrections & Calibration

FocuZ keeps correction and focus settings per lens (L1–L8), so swapping lenses doesn't mean re-tuning. This section covers selecting a lens, distortion correction, the work-coordinate offset, focal height, and aligning the mark to the part.

Lens management

  • Pick the active lens (L1–L8) from the lens selector. Each lens carries its own field size, correction, work offset, and focal Z.
  • Selecting a lens shows a short summary of its settings.
  • When the lens needs a known Z reference, FocuZ may prompt to home / jog before marking (see the homing gate).

Distortion correction (the Corrections dialog)

Open Corrections from Device ▸ Lens Corrections (it applies to the currently selected lens), or during Device Setup. It has two modes for correcting galvo/lens distortion, and remembers settings per lens:

Load the .cor correction file your lens uses — the same file format EZCad2 and LightBurn use. The file supplies the distortion map and field size. You can optionally fine-tune Scale and Angle on top of it. (Manual-only fields are greyed out while a .cor is loaded.)

With no .cor, enter correction values directly:

  • Scale X/Y and Angle
  • per-lens Field size X/Y (mm)
  • Bulge, Parallel, and Trapezoidal correction (X/Y)

Or import them from a markcfg7: From device markcfg7 reuses the file the device was configured with (no file picking needed), and Choose markcfg7… imports from any file. Either way, if the file carries a different work offset, FocuZ asks whether to bring that in too.

Field size may be left empty — that means "not set for this lens", and the grayed number in the box is the device value FocuZ will use instead. Setting it correctly matters: field size scales every mark, so a wrong one makes everything the wrong size. From device markcfg7 is the quickest way to get it right, because it brings in the field size and the scale together.

Round at center, distorted at the edges?

That's a distortion-correction issue — load the correct .cor for the lens, or tune the manual values. See Troubleshooting.

Marks come out the right shape but the wrong size?

That's field size, not distortion. Check the Field size on the lens card — it shows the value in use and where it came from (.cor file, set for this lens, or the device default). With a .cor loaded you can trim the remaining error with the Scale boxes, which fine-tune on top of the file: multiply the current scale by target / measured.

WCS (work coordinate) offset

The WCS offset shifts the work origin so the mark lands where the part actually is. It's stored per lens. Set it from the lens's WCS control (it opens the Corrections dialog for the active lens).

The canvas origin (0,0) is the WCS reference point: artwork placed at 0,0 marks at the work origin, and moving art +20 in X marks +20 from that origin. The offset itself applies only when marking and tracing — changing it never moves artwork on the canvas.

Focal height (Z) per lens

Each lens has a focal working distance. Set it on the Lens screen (top menu), in the Motorized Positional Z section:

  1. Jog Z to the optimum focal distance.
  2. Enter an Offset (the distance between the baseboard and the top of your test material).
  3. Click Save Current Z to commit the focal distance + offset to the active lens.

The Offset can be updated later without re-finding the focal distance. The section's Instructions button repeats these three steps in the app.

Motorized Positional Z shows its controls only when a FocuZ compatible controller is connected and the Z axis is enabled (Device ▸ Connection). Until both are true the section says which one is missing — without a motorized Z there is nothing for FocuZ to save a focal height against.

The Info section below it lists the active lens and everything stored against it: the correction source, field size, angle, WCS offset, and the saved focal height + offset. The screen's title names the active lens too — Lens L2, for example.

Then Home & Jog to Lens 0 (on the Jog window) gets you straight back to focus for that lens.

Finding focus: the Z Focal Distance

The Z Focal Distance (Sequencer ▸ Calibration) finds the optimum focal height empirically: it marks a row of numbered tick marks, stepping the Z height between marks — the sharpest mark is your focal height.

  1. Add a Z Focal Distance action. In Setup, set the number of 5-Mark Groups, Mark Spacing, Mark Height, and Label Height — the pattern on the canvas updates as you type.

  2. On the sublayer, set the Z Distance per mark and pick the mode: Motorized (FocuZ jogs Z between marks — needs the FocuZ:grbl controller connected and Z homed) or Manual (FocuZ prompts you to move Z between marks yourself).

    Stacked (Setup checkbox) marks every line — number included — at the same spot (the pattern's Location) instead of in a row, so the material must move to a fresh spot between marks. Checking it adds a second sublayer that advances the material along X: on Motorized (offered when the X axis is enabled) FocuZ jogs X by its Distance between marks — no prompts needed; on Manual FocuZ prompts you to move the material before each mark (in Manual Z mode the prompt covers moving Z and the material together). Useful when the surface only offers one good marking spot, e.g. a narrow or curved part. The canvas still shows the laid-out row; the Preview shows the stacked output as it will mark, one line at a time. 3. Run, then inspect the part for the sharpest, cleanest line. 4. Motorized — enter that mark's number when prompted and FocuZ jogs straight down to its focal height; save it to the active lens via the Lens screen. Manual — move Z down by that many of your steps, then save the same way.

Aligning the mark to the part

  • Calibration ▸ Offset (a Sequencer action) lets you mark or trace a target, drag it on the canvas to where it actually landed, and apply the difference as the work offset. The layer header's Apply Offset (Lx) button names the currently selected lens right in its label, so you can see whose offset will be updated before you click. The Return to 0,0 checkbox next to it (on by default) snaps the target back to the design origin after applying — with the drag absorbed into the offset, that's where it now marks, so a re-trace lands on the same spot on the material. Untick it to keep the target where you dragged it instead.

  • Red Light Trace (Device menu, or the Red Light button at the bottom of the Corrections dialog) helps align the red pointer to where the IR beam fires (they have a small fixed parallax). The red-light offset, scale, and trace speed are stored per lens — like the other corrections here, they apply to the lens named when you open it — while repeats and durations are device-wide. The window is organized into Calibration (red light toggle, per-lens offset and scale), Locate (move the pointer to a position or the field center), and Timing (per-lens speed, plus repeats and durations). An Import markcfg7 button at the top loads a file's red-light offset, scale, and speed into the boxes — nothing commits until Save.

    To dial the alignment in, the easiest route is the Calibration ▸ Red Light sequencer action: it marks a centered reference square (default 90% of the field, always a square at the field center, work offset ignored so it lands truly centered), then opens this window ready to go — the square size preloaded and the red-light square already tracing. Walk the red square onto the burn with the jog pad (each press nudges the offset by the Distance step) or by typing offsets directly; the square moves live. When it sits exactly on the marked square, Save commits the calibration to the lens. The same Square button works any time you open the window yourself, against any square you've marked.

Per-lens actions confirm the target lens

Actions that change per-lens calibration apply to the currently selected lens and confirm which lens before applying — double-check it's the right one to avoid mis-calibrating another lens.

See also