Prepare a laser engraving photo without guessing depth

Converting a photo to grayscale preserves brightness. A depth map tries to preserve structure. Those are different inputs. A bright forehead and a bright wall can share the same gray value in a photo even though only one is closer to the camera. The workbench estimates relative depth and then lets you decide which end should engrave darker or deeper.

That decision depends on the material and the laser mode. On wood, a darker burn usually means more energy; on coated metal, the coating changes the result. The file does not know your power, speed, focus, line interval, or number of passes. It only gives you a controlled grayscale field to test.

Use the invert control to create both interpretations of the same subject. Open the file in your laser software and check the preview at the final size. A reversed field can look plausible on screen and produce a mirrored face on the material. Confirm the direction with a small test before the final burn.

Raise the black point to quiet the background and lower the white point if a small near region is compressing the face. Contrast separates the midtones, but too much contrast turns skin into a poster. Make one change at a time and keep the source visible so a soft error does not become a hard edge.

A laser cannot resolve detail smaller than its beam and line interval. Fine eyelashes, jewelry, and fabric texture may disappear or turn into noise. The manufacturing check reports a detail figure against the beam size so you can reject a source before the burn. If the detail is below the beam, simplify the image or accept a softer result.

Tonal slices matter too. A shallow material or a low-power job cannot reproduce every level in a busy depth field. Smoothing the map and reducing the number of competing features often produces a cleaner engraving than preserving every highlight. The goal is a readable portrait, not a histogram.

Speed, power, focus, interval, air assist, and passes belong to the material test, not to the depth map. Cut a small sample from the same batch, engrave a test strip, and inspect the darkest and lightest areas. If the result is too dark, change the power or speed; if the shape is wrong, change the map.

Record the file, the material, and the settings together. When a customer asks for a second plaque, you want to reproduce the result, not rediscover it. The free preview and the paid production bundle give you a documented image input; the machine recipe remains yours.