Photo Engraving on Metal

High-resolution image work on the fiber. The 70mm lens is the right tool, the small spot resolves dither patterns cleanly.

Image prep

1. Start with the highest-res source you can get (ideally 600+ DPI at final size).
2. Crop and convert to grayscale.
3. Adjust levels: black point and white point should match what your laser can produce. On stainless: black = full anneal, white = bare metal.
4. Apply unsharp mask. Dehaze if outdoor photo.
5. In Lightburn: image layer, set DPI to match line interval (e.g., 0.02 mm interval = 1270 DPI for raw-stainless photo work), choose dither: Jarvis or Stucki for photographs.

Settings (photo on raw stainless, 70mm)

0.02 mm is the standard photo line interval on a 70mm lens (~20 µm spot size, finer hatch produces overlap without quality gain and roughly doubles runtime). For pure black-on-stainless oxide-layer marking (a different technique), the same 70mm lens uses tighter 0.01 mm overlap on purpose to grow the oxide layer. See Black Mark on Stainless Steel.

Anodized aluminum photos

Easier than stainless for photos because the contrast is white-on-color. Same dither, but pulse 8-15 ns and power 30-40%. Very forgiving.