Can't get good lens calibration after following all the instructions

[Dannym (Danny Miller)]

Moved discussion over to prior thread, plz delete this thread if you like

Aruducam 16MP calibration

(I had this posted as a new thread, I think it’s better here. I can’t delete the other thread though. Still need help!) Been working to get better lens cal in my 16MP Arducam. Great camera! But my first cal was a bit dicey- you can adjust the X/Y offset/width to dead nuts on any 2 points on the bed, but other points were often 2-3mm off due to limitations in the lens cal. Much more so near the edge. Glued the card to wood, no wrinkles, focused camera, covered the honeycomb. This is with the …