Related to Discussion: 0.5" focus range not achievable

[leahgee2]

thanks again…
question: if you believe the acceptable range is only 40%± of 0.008", how would you explain the many successful “prints” on warped material, or curved surfaces? such as this one, where the user assumed continuous autofocus was already implemented:

Autofocus saves the day

Didn’t notice how warped this piece of Proofgrade Maple ply (actually two are twist warped a fair amount). So put this in without noticing, and fired off one of the sheets of puzzles. I was sort of glancing, but not really looking too close, until I realized parts were dropping during the cut phase by over 1/4", and a few weren’t falling down completely so were at a tilt as they wedged against other pieces!!! I was standing like a hawk after that waiting for the fire as the beam defocused. Pfft.…

and many more, including ipads, rat’s skulls (!!!) etc…
(which brings up the point that the term “acceptable” is definitely up to interpretation…)

the fact that the failure of many “prints” have been attributed to warped material might have to do with a weakness in the 1-point autofocus system, which - since as you explained uses the camera to estimate distance- might grossly miscalculate distance because of parallax -compounded displacement (again, I don’t yet have a GF, so I have not seen it work)