Focus ?

[Bert Kemp]

I often read to get a darker burn or contrast to take the laser out of focus a little. Does it make any difference which way you move the table. Do you get a better contrast moving closer to lens or further from lens. Or does it matter at all?

[Gary Hair]

As far as I know, the beam is hourglass shaped so it shouldn't matter. That said, I always move it up - for no reason other than consistency.

[Bert Kemp]

LOL you got me You move the lens up further from the table or you move the table up closer to the lens ? LOL

As far as I know, the beam is hourglass shaped so it shouldn't matter. That said, I always move it up - for no reason other than consistency.

[Gary Hair]

you move the table up closer to the lens

This is what I do

[Robert Schmiede]

I have a ruler,part there of, glued to the frame of the machine between the up and down table so I can bring the table up closer to the lens to my prefered out of focus height. Ruler is vertical.

[Dan Hintz]

It generally doesn't matter, but I choose to move the table farther away from the lens. Darker lines = more smoke, so more distance between said smoke and my precious optics is always appreciated.

[Chuck Stone]

Personally, I never cared for the softer focus. Slowing it down a little gives me
the deeper color without sacrificing the sharpness.

[Bert Kemp]

Very neat Idea TY

I have a ruler,part there of, glued to the frame of the machine between the up and down table so I can bring the table up closer to the lens to my prefered out of focus height. Ruler is vertical.

[Bert Kemp]

That makes good sense too

It generally doesn't matter, but I choose to move the table farther away from the lens. Darker lines = more smoke, so more distance between said smoke and my precious optics is always appreciated.

[Bert Kemp]

Yes but doesn't that make the engraving deeper my material is 3mm so I don't want to go thru.

Personally, I never cared for the softer focus. Slowing it down a little gives me
the deeper color without sacrificing the sharpness.

[Chuck Stone]

Yes but doesn't that make the engraving deeper my material is 3mm so I don't want to go thru.

Sure .. a bit deeper. So I back off on the power a little
to compensate.

I'm not sure I'd do this if I did heavy engraving all the time, I'm
sure the extra time would add up. But as it is, on a full bed
engraving that might take 30-40 minutes or so, I don't notice it
taking longer. If I were a busy shop I might pay closer attention.

[Keith Colson]

When you engrave out of focus the engrave does not go as deep, it just gets a lot darker. I have a 22 hour job I am running which starts tomorrow. It would be 38 hours and unaffordable if I did it in focus but slower. The trick to doing it out of focus is to compensate for it in the artwork. I still get a sharp edge, its like colouring something in with a marker versus a pencil. No pencil lines and much faster. I will try and post a photo when this job is complete, the customer took the sample. Its almost black in colour. I got the job due to my quicker and lower price and he like the burnt look better too. I still billed the customer 3.5 hours @65 for the out of focus artwork and test sample.

Like Dan I put the bed further away to keep the optics clean. You also have more travel in this direction too.

[Bert Kemp]

Thanks to everyone I have a pretty good Idea nowof which way to go and how much and a ruler attached to keep track. I don't engrave a lot but I would like more contrast on what I do do thanks for all the good info.

[Keith Colson]

I completed my out of focus test run today, here is a comparison of the job done in focus by my competitor and the out of focus burn I did. These were both done in low resolution e.g. density 2 in the universal's 1 to 7 choice.Higher densities would have killed the job on hours. The focus was set 10mm out. The grain really pops out nicely.

compare.jpg

[Bert Kemp]

Yes really does stand out.