Is this the best I can do?

[Pete Thomas]

A question for the experts and years of experience I've seen in this forum. I've been trying to engrave a picture of one of my dogs into a lacqued piece of cherry. Attached below is my result.

The question is this the best I can do. I feel that I should be able to get a better looking result. I started with a picture at 200dpi and converted to grayscale and then processed using photograve, selecting cherry as my material and using all the defaults.

My system is a ULS 60W, I used settings of 100pwr 60spd ppi=500 ID=2. I also applied a liquid black shoe polish which helped alittle.

I've attached my grayscale as a jpg as there is an upload limit on the .bmp file sizefile, the filename is begin.jpg. The photograv output file is new_1_16_pge.bmp. The final result file is result_72.jpg.

I have also been trying various black&white setting to dither the image in photoshop & Corel, but so far have gotten the best result from photograv.

I hope that I supplied enough info in hopes that someone might help me improve my final result.

Thanks to all for any comments,
-pete

[Lee DeRaud]

You can probably do somewhat better, but the main problem is that the original picture is low contrast. By the time it gets through a process that basically reduces the dynamic range to one bit, there's just not much left to work with.

The last black dog I had, she was almost impossible photograph well: anything except a color photo in bright sunlight might as well have been a silhouette.

[Pete Thomas]

Lee, I purposely dropped the contrast down by raising the gamma in Photoshop/Corel. I was trying to minimize lasering everything away where the black was and trying to achieve a good contrast. I have seen in the past that the image in Photoshop may look very poor but final result came out very good. An example of this was when I worked 6 hours on a dog image that was engraved in some granite. It really amazed me how the image on the screen looked as compared to the final output. Having the image inverted for granite did have quite an impact, but if I recall reducing the dynamic range really helped pop the image out of the granite.

-pete

[J Porter]

yep... tuff photograph. You might try the Brightness/contrast control in Corel. On the original .bmp file, increase the brightness about 15 points and reduce the contrast by a like amount. You actually want the .bmp on your screen to appear a bit lighter than you would like it to be.
Then process it with Photograv.
Probably the only other thing that might help is to use a 1.5" lens (I'm assuming yours is a 2").
I have no idea if the laquered finish would affect the outcome. I usually laser on bare wood and then apply a finish afterwards. When I do laser a finished surface, I add a few points to the laser's power than what Photograv suggests to get through the coating.
I have, on occasion, seen a photo like this that turned out much better when I lasered the inverted picture..... just an idea.

[Barbara Buhse]

I do a lot of pet pictures... there is always very little contrast. Pet hair does not reflect light like human hair does. Try using a photo editing program (I use a simple one, Microsoft Picture It). There are a few things you can do before Photograv... change to Black and white BEFORE these steps, so you can better judge the results.
1) Lighten the brightness, and then increase the contrast.
2) Use the "emboss" filter... The picture will look very strange with the embossing filter, but you'll definitely see a difference when you photograv it. Sharpening does not always work with pets.

Hope this helps... if you don't have an editing program, e-mail me the picture and I'll see what I can do.
pesce@aol.com

Barbara

[Rick Maitland]

I also think your power setting is to high for a 60 watt laser. I get great results using your same settings but with a 30 watt machine. To much power can engrave away much of the detail.

[Ed L Miller]

Hi all,

Here's a little tip that will certainly fix poor quality engravings. First of all I've found ( after creating tons of firewood )that when performing photograph engraving, you only want to skim the surface. Some types of substates will require deeper engraving that will make the image *POP*; however, most hardwoods ( Alder, Maple and Cherry ) are best engraved with no more than about .025" depth.

Of course, if you have a photograph that doesn't cooperate, you'll have to get a bit creative and that's what I'm going to share today. :)

FIRST STEPS ( preparation ):
I first scan the image in at 300DPI full color.
If I have to do any edge enhancements or balancing as well as removing the background, etc. I use Paint shop pro. Try to avoid increasing the contrast too much, the output won't look nearly as nice as it does on your monitor.

Once I have the image just right, I import it into CorelDraw. I size the image and typically apply a vignette to it.

I then export the image as a Greyscale bitmap and load it into PhotoGrav or something similar ( I can't tell you what that is right now ).

Anyway, if we're dealing with PhotoGrav, I then will load in the Cherry params or a customized one that I've modified. Considering I'm using a ULS VL200, I have PhotoGrav set for 500DPI.

After I've performed the auto processing, I save the image and import it back into CorelDraw.

I then proceed to engrave the product. I'm using a 30Watt machine; therefore, I typically run the following settings for Alder and Cherry. I will increase the power to 75 if the wood has been clear coated with 2+ coats.

Power: 65
Speed: 100
PPI: 600
Density: 500DPI

By running the settings shown above, I usually wind up with pretty good results; granted the image was good to begin with.


Ok, so here's what I do if things don't turn out as planned.

This will only work if you have a flat piece of wood ( Plaque, box top, etc. ).

I run the product through my surface planer, making sure to only take a small shaving each time. After removing a few 1000th of an inch, you'll have a very nice looking engaving that looks quite nice.

Once I'm done with the planing, I will apply a couple of coats of hand rubbed Bulls Eye shellac. After the first coat I use 600 grit aluminum oxide to smooth any raised grain. You want to be careful not to get any shellac in the engraved area; therefore, don't wet your cloth too much.

I've managed to save a good deal of plaques and box tops by this approach. Hopefully I've helped some fellow woodworkers/engravers out there. ;)

-Ed

[Rodne Gold]

The image you have posted is a lousy image for engraving , its not sharp (looks like there was bad camera shake or double blur) and is very low in contrast and has no detail , I would be surprised you get acceptable results with it no matter what you do. I dont think it can be at all salvaged and wouldn't bother trying. You might get slightly better results by using an unsharp mask of 400% with a radius of 1 pixel , but even when I tried that it was bad.
Just as an aside , ppi (pulses per inch) is not relevent in raster engraving , it's only used in vector cuting.
Rather scan at 600 ppi (pixels per inch) if you can , you can reduce the ppi later , but you cannot retrieve detail if it doesnt exist in the first place(a low ppi/dpi scan)