User talk:AndyE: Difference between revisions
From London Hackspace Wiki
no edit summary
No edit summary |
No edit summary |
||
| Line 27: | Line 27: | ||
If we wanted to get the same resolution we'd need to pick out 256 shades of grey to laser, or better still hack the laser software to allow us to control the burn strength per pixel. | If we wanted to get the same resolution we'd need to pick out 256 shades of grey to laser, or better still hack the laser software to allow us to control the burn strength per pixel. | ||
Ah, did the test image on my laser at home. | |||
Didn't think to upload the file anywhere alas. | |||
The first test I used all 8 images starting at a speed of 500 and strength of 15 and doubling each layer | |||
This blew all the way through the MDS and left a delicate filligree of utterly burnt wood in a barely recognisable cake shape. | |||
The second test I used only the last 4 images | |||
Speed, power | |||
500, 15 | |||
500, 30 | |||
500, 60 | |||
250, 60 | |||
That produced the depth relief I uploaded a photo of. | |||
I've not tried acrylic so far, but I suspect that 5mm opaque acrylic will give better for 3D and that for greyscale on wood we need a different approach for the thresholding. | |||
Rather than the successive burn binary approach a simple 8 layer light-> dark threshold should work, though some cleverness is going to be required to get the banding right. | |||
Something akin to this will give us 10 files picking out 10% brightness bands for burning at different strengths. | |||
Darkest | |||
gm convert -type grayscale -colors 10 -white_threshold 10% -solarise 10% -black_threshold 0% -negate -black_threshold 99.9% (infile) (outfile)_1 | |||
Next darkest. | |||
gm convert -type grayscale -colors 10 -white_threshold 20% -solarise 20% -black_threshold 10% -negate -black_threshold 99.9% (infile) (outfile)_2 | |||
etc | |||
I'll have a fiddle come lunchtime | |||
