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View Full Version : Laser Tiles and photograv



Jim Brodkorb Jr.
09-02-2007, 4:42 PM
I have read some threads on the laser tile and people using photograv and others saying that you don't need to use photograv. If you use photograv, what have people used for the material in photograv? I've tried the white corain and it seemed to turn out ok. Also if you don't use photograv and just convert the pic to grayscale, do people leave it as a jpg file or save it as a bmp file?

Thanks again for all the advice.

Jim

Darren Null
09-02-2007, 8:03 PM
Photograv is best. Basically, the program uses quite a sophisticated algorhythm to convert an image to a 1-bit (ie, black and white NOT greyscale) image. Also, it'll give you a reasonably accurate (I believe) preview of your image as it'll look on a variety of materials.

There are other methods of turning an image into 1-bit including a couple of photoshop filters; boiling the image down into a GIF; using CorelDraw's native 1-bit conversion (floyd for preference); or your laser's driver probably has dithering methods too.

Greyscale is various shades of grey; which means that there is further work that needs to be done before you output it....a laser either creates a pit or it doesn't. It can fake greyscale by a choice of dithering methods, but can't actually do it.

Photograv, then, turns your image into a particularly laser-friendly 1-bit image, and from the outputs I've seen, leaves other methods behind.

If you're using CorelDraw to feed layouts to your laser, turn your image into a TIFF. CorelDraw doesn't like JPEG or PNG formats, but works with TIF and doesn't seem to mind PSD (Photoshop native format). BMP may well work too.

Scott Shepherd
09-02-2007, 8:45 PM
I'd like to respectfully disagree with my friend Darren. I believe LaserTiles do very well in greyscale. The sample images they give as well as the images they sell are not photograv images and they are razor sharp and have various shades of grey. I tend to think of LaserTiles in the same category as AlumaMark. I think both do very well with non-photograved images. I don't have Photograv and just in messing about with it, I have burned some nice looking images on both laser tile as well as Alumamark.

I've also not have any problems using JPEG's in X3 at all. Maybe it's a driver issue for Darren, but I've not had any issues with images (knock on wood).

Of course, I could be completely wrong on all of it. Wouldn't be the first time (nor the last).

Bill Cunningham
09-02-2007, 11:12 PM
If your not sure what to material to profile in photograv, choose the vertical grain cherry.. Thats the swiss army knife of photograv and works with just about everything..

Darren Null
09-03-2007, 5:26 AM
On the subject of respectful disagreement...
=8-)

I may have given the wrong impression- I wasn't saying that you can't use greyscale...you can give the laser a full-fat colour image and it'll cope. You will get a better idea of the final output with greyscale because you don't get colour with laser (until somebody coughs up one of their super-secret methods). But greyscale isn't what you get as a final output. What you end up with is a 1-bit image dithered to fake greyscale.

Whether you leave this final-stage conversion to 1-bit to your laser driver, or whether you choose to do it yourself (using Photograv or a wide variety of other methods); the fact remains that the final output is going to be a 1-bit image for most materials.

As to trouble with CorelDraw and JPEG, it's in this thread:
http://www.sawmillcreek.org/showthread.php?t=64540
...it might just be JPEGs from Photoshop, but there is definitely an issue there. If you use TIFF or PSD images you're not going to encounter the problem. Just trying to save somebody else the same headache I had.