Originally Posted by glintid  All laser engravers are two bit, ie. bitmap devices similar to a fax when it comes to outputting non-vector images. The laser can be on or off at a specific power level. I think that the power level is varied by varying the pulse frequency too. so, we rely on software to convert multi-bit images to and convert them to 2 bit images. Some more expensive lasers have the ability to convert in the driver. Rabbit lasers (I have the 6090SE) requires the user to convert the image in a software program like Photoshop or Photograv or other image editing program. Typically, the image is converted to a half-tone made up of black dots of varying sizes and spaces to estimate the "grey scales" of the original image. This enables the laser to burn the image into the substrate.
The problem I had at the beginning is that I used a speed that was too great. The result was that the laser didn't have enough power, or didn't linger in one spot long enough to create the dark shadow areas of the image. The result being that the highlights and the mid tones of the images werefine but the areas that were supposed to be dark were mid tones or appeared solarized (reversed from their original tone). The solution is to adjust the speed and the power down until you get the shadow areas to read correctly. I found this by trial and error, it's not mentioned in any literature.
First, create a sample of grey shades from 5% to 95% and process it in your software and convert it to a 2 bit image. Then try varying power/speed combinations for each material used to get results that reproduce the sample as accurately as is practicable. You'll learn a lot from this exercise. I know I did and, I quickly found that the max speed quoted for the 6090SE is severely limited by the laser power.
This phenomenon I found is not always linear. In other words, the 5% to 80% shades are accurate but the 90% is not reproduced.
Experiment, experiment, experiment, that's all I can suggest and , record your results for future reference. |
That's what I figured. Try and error. Sometimes the only way to learn.
Ive done a couple of test now and I still cant figure out what the "scan gap" and "expand scale" boxes do? It would of been nice if somewhere in their stupid manual it explained the differences.
Anyways, Thanks for your advice!