Dithering help needed - config, troubleshooting steps included

I’ve been struggling to get an acceptable image engrave for months with little success so I’ve broken down and resorted to asking for help. Below, I’ve done my best to outline the problem, the setup I’m using, the testing & troubleshooting I’ve done and the results. Please help!

Problem: Picture engravings come out in a blotchy mess.

Setup/Config:

  • K40, brand new tube (used K40 rec’d in “basket-case” condition
  • SKR v1.3 mainboard running Smoothieware (config)

Troubleshooting: (tests performed between 50%-100% power, 20-30mm/s)

  • Focus test - Looks good
  • New Interval Test in LB (overall) (focus on 0.07mm)
  • Vector engraving is fantastic
  • Calibration is spot-on in both X, Y (1mm=1mm, 10=10, 100=100, etc.)

What other testing can I do and what am I doing wrong?

Are you using the ‘adjust image’?(right click image and select adjust image)
Easier to use than ‘preview’
Adjust gamma to 0.650
Contrast to +7
Go from there, slight adjustments, hope you have scrap practice pieces.
Let it run for a couple of minutes and pause, if it looks wrong, adjust and use preview to start laser from…(uses a lot less material and time)

Well, those suggestions have granted me more progress in 24 hours than I’ve been able to make in several weeks - thank you! I’ve still got a ways to go before I’m able to achieve the results I see others attain, but the two biggest things that helped me were the contrast that high, and OMG the right-click → Adjust Image is a lifesaver. Thank you!

I’ll post anything significant if I run across anything in hopes it may help someone in the future.

Had mine since dec 2020.
Not had what i would call a great picture yet(passable) :thinking:
Not had the time for lasering but loving the learning from the peeps here on the forum.
Best of luck.

With the hours of troubleshooting I’ve done, I’ve come to the conclusion that the PSU may not be switching fast enough, which is why I can’t get anything but continuous lines on the dot test. With no oscilloscope to test, I bit the bullet and ordered a new PSU which should be here tomorrow. I’ll post results, but given the poor condition this thing was in when given to me, I’m thinking this is a safe bet. If nothing else, I’ll have a spare.