Hi! New user here! I’ve watched the basic videos and done some research but I’m having difficulty determining if my contrast and brightness settings are correct. I’m testing two versions of an image, a bitmap BW and a straight grayscale image. Both are pictures of a dog. When I upload them they look fine in the editor. Once I process them, they look really dark. When I generate the G-code they are even darker. Which one is it going to look like when it’s finally engraved? I’ve tried changing the contrast and brightness but on my first test print, the engraved images looked much lighter than what was on my screen. Help!
I think at some point Luban stops showing you the power when it renders, and instead anything that is a motion of the machine is just black. I wouldn’t worry about the gcode render being black.
Haven’t used the process section of Luban, but maybe that’s related.
The bigger issue is the settings have very little to do with what it will look like, as it would be impossible for the software to know how dark the laser will etch the material at a given speed and power. You need to do some material tests with various power settings and speeds to figure that out, and then set the process parameters based on that. Snapmaker has some starting points on their site.
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Preview in luban as @brent113 said doesn’t tell you much. Have to do tests.
Take a small section of the image, say 10mm x 10mm. Choose a section that has a good range of contrast/detail. Use that as a sample and import it into Luban. You can then duplicate that sample image and set a range of settings to try. (I usually do 5-10) I would start first with leaving any image settings at default, set work speed to 400mm/m (seems to be a good starting point for me) and try changing power settings. Pick the power setting you like best. Then it’s really just deciding if you want/need to do more tests. You can try changing image settings. Try changing speed/power relationship. (100% at 400 vs. 50% at 200)
Every type of wood (and even piece of wood) is going to react slightly differently.
You may also need to adjust your contrast in a program like Photoshop or GIMP that gives you more control over your image than Luban does. You do need a fairly contrasty image.
-S
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I will grab half his face and print that a few times at different speeds and power. Does it make a difference if the image used is a standard grayscale jpeg vs. a bitmap? Thanks so much!
Never used bitmap.
Usually prefer PNG over jpeg because I find compression better.
But a high quality jpeg should be fine.
Someone calculated that the laser resolution is equivalent to ~230 dpi on an inkjet printer.
(If I remember correctly, could’ve been 260, somewhere around there)
-S
I could just say, trail and error is what you have to do.
If I want to engrave a large object I do at least 4 miniatures of this as a trail to get finally big.