Getting a clean photo engrave in Light Lane: image prep, DPI, and algorithm

DPI too high is the most common mistake. More dots per mm means more overlap between adjacent burn spots. On wood, overlapping burns produce a darker, less detailed result rather than a sharper one. Start at 254 DPI (Light Lane's default), which gives you 10 dots per mm. On very fine-grained materials like MDF or leather you can try 380 DPI. Going above 380 DPI on most diode lasers produces burned-together dots that look darker and muddier, not sharper.

Wrong dither algorithm for the image type is the second common issue. Floyd-Steinberg distributes error to neighboring pixels with a serpentine diffusion (7/16 right, 3/16 down-left, 5/16 down, 1/16 down-right) and produces smooth tonal gradients. It is the right starting point for most portraits on wood. Atkinson uses a lighter diffusion that preserves highlights better, which works well for high-contrast subjects with bright areas. Bayer uses a fixed geometric pattern that looks mechanical on natural subjects but can work for graphic or stylized images.

Power too high for the DPI is the third issue. At 254 DPI with 70% power, you get a particular energy level per dot. If you then increase power to 90% without changing anything else, the dots get darker and start to merge in the midtones. The solution is to use the Material Test Grid to find a speed and power combination that produces a clean mid-gray at your chosen DPI, then use that as your base.

Image preparation also matters. A portrait for wood engraving often needs more contrast than a portrait for screen. Boost contrast and reduce brightness slightly before importing. Light Lane's image adjustment panel has contrast and brightness sliders. Additionally, increasing sharpness slightly before converting to dither produces crisper dot edges.

The AI Engrave Assistant in Light Lane can help with image-specific setting adjustments for a selected photo. Select your image on the canvas, then open the AI assistant panel. Describe the issue: "the portrait is coming out too dark in the midtones" or "I want more contrast in the shadow areas." The assistant analyzes the selected image and proposes changes to DPI, dither algorithm, brightness, contrast, and processing settings. It shows you a settings diff before anything changes. You hit Confirm to apply, or Dismiss to leave settings as they are.

The AI Engrave Assistant does not control speed or power. It handles image processing settings. To find the right speed and power for your material, use the Material Test Grid first. Once you have confirmed speed and power from the test grid, open the AI assistant and tell it to respect the existing speed and power values while optimizing the image settings for your specific photo.

These are two separate tools used in sequence, not interchangeably.