Z offset when cutting

[Bob Marino]

Is it best to use Z offset when cutting material?

For example,
Focus is 5mm from Tip of laser
Wood Material is 3mm thick

Should i use an offset of 1.5mm?
What about for 6mm material? 3mm Offset?

What is best practice?

Thanks

[Gene Uselman]

I don't really take that into consideration unless the material is approaching the limit of my laser- then sometimes it is helpful. I have a lot of power- your results may vary.

[sebastien laforet]

for 3mm material, the difference will be barely visible, unless you use a very short focal length.

with a 1.5" focal, and 6mm material, it begins to be useful to lower the head by 2mm. in my experience, it is not the best to target the exact middle of the material.

with a 2,5" focal, this makes no difference offsetting the head for such a small distance.

[Gene Uselman]

Russ has been exploring this lens focus question in a lot [a lot] of detail... I am not sure he has any conclusions yet

[Bob Marino]

Thank you both for your comments. I will use your opnions to guide me.