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Paul Anthony
10-11-2007, 9:46 AM
We are experimenting with photos on glass and can't seem to get any detail. Most everything we do comes out all frosted and the face is undistinguishable. Any suggestions? BTW we tried overlaying wet newspaper and it didn't help.

Frank Corker
10-11-2007, 10:21 AM
Paul it helps to supply details of what type of laser you are using. Most of the problems that you are encountering are probably to do with the dpi setting of your photograph.

There are a number of problems and a good read of the forum will probably help you. Here is a picture of my neice Lucy, have a look at it and try engraving it at the recommended glass settings for you laser.

If you are still having problems, PM me and then email me the picture that you are trying to engrave so I can see your problem

Frank

Paul Anthony
10-11-2007, 10:30 AM
Sorry about leavibng out that we have an Epilog 60

Darren Null
10-11-2007, 1:05 PM
If all you're getting is silhouettes, try dropping the DPI to 300 (first) and a bit lower (maybe 150) if 300 doesn't work. Depends on your machine and the glass, but what's almost certainly happening is your higher dpi is overburning bits of the glass and killing the detail.

Peck Sidara
10-11-2007, 6:24 PM
Paul,

Attached is a sample I did on cheap replacement glass panes from Home Depot. Engraving was done on a Mini 24, 35Watt. Settings are as follows:

40% speed
70% power
200DPI

Photograv and its glass settings were used.
Some adjustments to brightness, contrast & intensity were done to the image in CorelDraw as well.

Image was submitted as a jpg.

DPI was the main factor. Black anodized was place behind the glass for contrast.

HTH,

Stephen Beckham
10-11-2007, 10:10 PM
Paul,

One other thing I would add to the DPI issue is Contrast. If you have greyish colored people on a greyish background - not going to work. I cut most of my people out of the image and paste a black background in the image before using photograv. It forces a vast contrast between the people and their outlines.

I also like to double my DPI when burning - if using a 300 DPI image, I etch it at 45 speed/100 Power at 600DPI. (I'm using a 45 Mini 24 for power reference). When using a 200DPI, I use 35 speed/100 power at 400 DPI. Although it sounds backwards, the more detail in the photo, the lower I change the DPI to force Photograv to distinguish between the different shades.

One last note - I've never been able to distinguish more than three shades of grey with the naked eye on the glass. If you image is too detailed with a lot of shading changes, the divits will mesh and create one big blur... One thing you can do is make up a grey scale chart and burn it to glass - see where your detail breaks up between percentage of greys. It won't help with photos, but it will give you the opportunity to see what the difference is between the divit spacing.

Larry Bratton
10-12-2007, 8:42 PM
We are experimenting with photos on glass and can't seem to get any detail. Most everything we do comes out all frosted and the face is undistinguishable. Any suggestions? BTW we tried overlaying wet newspaper and it didn't help.
Paul:
Engraving on glass creates a huge amount of dust that sticks to your focus lense. Be sure you clean it often. I recently did several pieces with glass and I literally had to clean the lense after 2 pieces or my quality suffered. A dirty focus lense will really mess you up, so it's important to watch it.

Bill Cunningham
10-13-2007, 12:21 AM
Wipe the glass down with a layer of dish soap first.. Even when dry, it seems to congile and keeps the glass dust from hitting the lens.. I laser thousands of pieces of glass every year, and none of it sticks to my lens.. Of course, I also have a 750cfm blower attached, so not much flys 'up' anyway..