Full Version: LaserSketch - Expectations?
From: Cody (BOBTNAILER) [#28]
1 Jul 2005
To: Shaddy [#27] 1 Jul 2005
Actually, all I do is resample and change the color mode in Photo-Paint. I don't do any of the sharpen/tune/contrast stuff - but only because I am not sure of what they do. I'm pretty ignorant about doing photos, so it's kind of ironic that we've been so successful with them.
Once we have a picture sized correctly (with resample), we change the color to 8-bit greyscale. That's all for Photo-Paint.
In PhotoGrav, I simply pick the material (sometimes I use the "stock" materials, and sometimes I use some parameters that others have sent to me). I only use auto processing. Again, I don't know what effect the other stuff will have on my final product, and I'm not willing to use a bunch of engraving stock to play with the settings.
Ours is a VERY simple process. However, we don't get NEARLY the results that you've shown us with your oval piece!
From: Ken D. (KDEVORY) [#29]
1 Jul 2005
To: Cody (BOBTNAILER) [#28] 1 Jul 2005
Cody,
Yes, you need to engrave a lot of photos to get a good feel for some of the settings/adjustments, but that does not mean using a lot of material.
If I'm printing a gray scale its .3" high by 6" long. For a pet memorial with a photo of a cat I used a 1.5" square from the photo. This contained most of the face and some of the body. One 12"x12" tile can hold up to 64 of these small squares. If you add labels under them, describing the settings, 56. I only engraved the full photo after I liked my settings.
To me buying two tiles, for 100+ test images, is just part of the "school fees". When I have a job, I work on it until I'm satisfied. Each one goes faster and easier. (I do try to have one good test image before taking a job using a new substrate.)
From: Cody (BOBTNAILER) [#30]
1 Jul 2005
To: Ken D. (KDEVORY) [#29] 1 Jul 2005
That makes very good sense.
Do you find that your setting change when you change picture sizes?
I have.
For example, I'll engrave a 2" x 4" acrylic paperweight at 100% speed and 80% power. The picture is actually about 1.5" x 3"
For the same photo on a 5" x 7" acrylic block, I use 100% speed and 60% power. Any more power than that, and the picture looks "washed out". This pic will actually be about 4" x 6".
I attended one of the PhotoGrav seminars in Vegas this year, but didn't learn enough to move me forward. I would LOVE to get some good hands-on training from someone who knows how to do this stuff, AND (just as importantly) knows how to relate it to me.
EDITED: 1 Jul 2005 by BOBTNAILER
From: Ken D. (KDEVORY) [#31]
1 Jul 2005
To: Cody (BOBTNAILER) [#30] 1 Jul 2005
No, I don't change any settings.
Its the same material, same photo, same dpi...
That said sometimes you need to compensate for variation in material. Harvey's numbers: double the power, 20% darker image; worked on one piece that was giving me problems, but I already had the base settings worked out.
Only difference is engraving the whole picture vs. a smaller, but representative, part of it.
If you change the engraved resolution the speed/power will also change.
If you change the magnification level additional photo manipulation may be required to optimize clarity of detail. (This is part of getting a feel for it.)
I am attaching a test pattern I've used on occasion. Engrave at a dpi that matches the image. Change the dpi to scale, don't resample. I'll print it at various speed/power levels, at each dpi, to help get a feel for a new material. Again it's small so it doesn't use a lot of material. I then use a 12x or a 30x magnifier to view the results. Its interesting how much detail you can't get.
From: Cody (BOBTNAILER) [#32]
1 Jul 2005
To: Ken D. (KDEVORY) [#31] 1 Jul 2005
Very interesting...
I just tried one at 600 dpi, and another at 300 dpi. The 300 dpi image lost a little bit of detail, but not much.
Something else that I may have to play with is my scanner settings for dpi. I hadn't even thought about that until now, but it will probably make some difference, too.
Do you scan at 300 dpi when you engrave at 300 dpi?
From: Ken D. (KDEVORY) [#33]
1 Jul 2005
To: Cody (BOBTNAILER) [#32] 1 Jul 2005
As a general rule I try to avoid resampling. I will usually scan at the desired output resolution, or do the math so when it is scaled to the desired output dpi the size will be what I desire. I feel this is more important with error diffusion than it is with pattern/halftone dithering.
At 300 dpi there won't be much overlap among the dots, so your power/speed needs to create a "full dot".
At 600 dpi there is overlap, so each spot is covered by multiple overlapping dots/pixels. For a good grayscale it should be "fully engraved" when all overlapping dots are on; a subset of overlapping dots should partially color it. This method will be very sensitive to having the power set too high. (In some respects this approach is similar to using the driver's 3D function when it is properly calibrated.)
From: Cody (BOBTNAILER) [#34]
1 Jul 2005
To: Ken D. (KDEVORY) [#33] 2 Jul 2005
Sorry...you lost me on that one.
I have no idea what error diffusion is. I am familiar with dithering only in the respect that it "pixelates" images as they are resized.
Can you give me an example of the "math" that you mentioned? I'm completely ignorant about that.
Perhaps this is the stuff that I need to find a good class in.
EDITED: 1 Jul 2005 by BOBTNAILER
From: Ken D. (KDEVORY) [#35]
2 Jul 2005
To: Cody (BOBTNAILER) [#34] 3 Jul 2005
Cody,
Check out thread # 942.1 "Halftone vs. Error Diffusion" in the Laser Engraving folder. You can enter 942.1 in the bottom of the left column under the folder list.
scan resolution = (engrave resolution x engrave dimension) / scan dimension
600 DPI scan = (300 DPI engraving x 2 inches engraved) / 1 inch scanned
150 DPI scan = (300 DPI engraved x 1" engraved) / 2" scanned
From: graniteman (MGARCIA) [#36]
8 Oct 2006
To: Ken D. (KDEVORY) [#1] 21 Feb 2007
hi Ken.
sorry to hear about the mishaps. im mark garcia, wholesaler of granite plaques. we are new suppliers but have a very good product to sell. if your interested i can email you a price list. our web-site is nearly complete but you are welcome to take a look at it. www.artistic-laser.com
we started our business plan with customer satifaction as our primary goal. so we hope to hear from you.
thanks,
mark garcia
From: graniteman (MGARCIA) [#37]
8 Oct 2006
To: precisionlaser [#6] 8 Oct 2006
hi Mark. im Mark Garcia of artistic-laser. we are a new granite wholesaler located in redlands, ca. (so-cal) we have a very good granite that you may be interested in. soon we will have hard black marble for sale. we are still waiting to move into our warehouse. but we are able to ship out product at this time. so we hope to hear from you soon.
thanks,
mark garcia
www.artistic-laser.com