How Do I Manually Focus A Laser Correctly?

A Step-by-Step Guide to Manual Laser Focus 

Proper laser focus is one of the most important (and overlooked) steps to getting clean, consistent cuts and engravings. If your laser isn’t properly focused, it won’t burn efficiently—no matter how much power you use.

This guide walks you through how to focus your laser correctly, including tips for thicker materials.

What Does “Focusing” a Laser Mean?

Laser focus is the point where the laser beam is narrowest and most intense—this is where it does the best job cutting or engraving. When your laser is too far or too close, the beam is wider and weaker, leading to:

• Incomplete cuts

• Blurry or thick engravings

• Burn marks or melted edges

What You’ll Need

• Your laser machine (diode or CO₂)

• Focus tool (usually a metal or plastic spacer)

• Calipers or a ruler (for thick material focus tricks)

• Safety goggles (always!)

How to Focus Your Laser (Standard Materials)

Most home lasers focus manually using a fixed lens height and a focus spacer/tool.

For Diode Lasers with Focus Spacers:

1. Lower the laser head until it touches the material.

2. Place the manufacturer’s focus spacer (e.g. 2mm block) under the laser head.

3. Raise the laser head just enough so the spacer slides out snugly.

4. Tighten the head in place.

You’re now focused at the surface of the material, which is ideal for engraving or cutting thin stock (2–3mm wood, acrylic, etc.).

For Adjustable Focus Lasers (Like Ortur, Atomstack, xTool D1):

1. Loosen the laser module on the Z-axis.

2. Slide it up/down to match the recommended distance (e.g. 20mm from lens to surface).

3. Use built-in rulers or a spacer tool to get it just right.

4. Lock the module in place.

How to Focus for Thicker Material (5mm+)

When cutting thick materials, the ideal focus point is halfway through the thickness. This allows the laser to concentrate energy more evenly through the cut.

Option 1: Manual Focus Midway

1. Measure your material thickness (e.g. 6mm).

2. Divide it in half (6 ÷ 2 = 3mm).

3. Place a 3mm spacer under the laser head instead of the usual 0mm/surface spacer.

4. Re-focus the laser 3mm above the surface.

Option 2: Focus Shift + Multiple Passes

• First pass: focus at surface

• Second pass: raise Z-axis by 1–2mm

• Third pass: raise again

This method simulates a progressive cut, which works well if your laser lacks Z-axis automation.

Bonus Tips for Sharp Focus

• Clean your lens regularly—dust reduces beam sharpness.

• Use thin scrap wood or paper to test focus:

  • A properly focused laser will burn a thin, crisp line.

• Listen: a well-focused cut often crackles or hums lightly.

TL;DR

•  Use your focus spacer or manual measurement to set the beam at the material surface.

• For thick materials, focus halfway through (or use stepped passes).

• Always double-check before every job—focus can shift from vibration or transport.

• Clean optics = better focus = cleaner cuts.