Photo engraving 2 @SarbarMultimedia

Uploaded April 2023 | Updated September 2026, 1 week ago

Part 1 was all about the therory of digital graphics and how resolution and image size are intimately entwined. Dithered images are based on pixels but there are limtations on what size pixels can be reproduced with hobby laser macines. This part 2 is all about creating small dots with a laser machne to emulate pixels. It's not as simple as most users think. There are many factors that will ultimately affect the size of a burnt dot. These include the material, the lens type and its orientation, the intensity profile within a laser beam and the laser beam control system.

This session demonstrates that if you can create dots to match a pixel size, then you can do photo replication with no image "interference" or "preperation".

The little 254ppi bitmap test pattern used in this video can be downloaded with this link
https://workdrive.zohopublic.eu/external/b8320305cb514fb43bc42afdbba89c8e1518a86607a6084b005d0cf5057ea15c/download

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$RDWorks Learning Lab 246 SPHERICAL ABERRATION. Our New Best Friend I have made several videos documenting my discoveries about the relationship that laser beams and lenses enjoy. Normal optics is well established for telecopes , cameras and microscopes etc These products use glass lenses to focus regular light images. Laser light obeys all the same laws of refraction that govern lens design but the non-uniform intensity profile within a laser beam sets it apart from normal light and the age-old predictions of lens theory about what happens after a focal point are no longer valid. For laser cutting, the beam stops at the surface of the material (usually the focal point) and light energy transforms to molecular kinetic enegy to effect material damage. There is no after the focal point as described by normal lens theory because we are not transmitting IMAGES. I have spent several years experimenting with lenses and laser beams in an attempt to understand the mechanism that allows cutting to happen below the focal point when conventional logic predicts otherwise. I reached an understanding of the basic cutting mechanism several months ago, but recent research into spherical aberration has allowed me to fully understand the many damage profiles and unanswered details I have obseved during my test work. I feel I have now fully masterered the many interwoven factors that allow this cutting miracle we all take for granted. I have created a PDF document called The Dark side of Lenses that is the basis of this video. it is a synopsis of my 3 year journey searching for this mechanism of cutting that I was unable to find described elsewhere. Hopefully it explains and demonstrates the many jigsaw pieces that build to a final picture. That PDF file can be seen and downloaded from https://laseruser.com/dark-side-of-the-laser-lens/ or www.rdworkslab.com The aberration simulator player: https://support.wolfram.com/topic/wolfram-player/download-installation The aberration simulation is : https://demonstrations.wolfram.com/SphericalLensAberration/$

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