Help needed for lasertile&epilog

[onur cakir]

Hi everyone !

First of all merry Christmas and happy new year to all.

I'm a newbie on laser business and expert on decoration business

Here is my problem; i'll be on a decoration fair in Istanbul 2 weeks later and i'm prepearing 31" wide and 55" height wall panel from a Bouguereau artwork.

My settings are

Epilog mini24 45W ( brand new )

Speed : 65
Power : 60

400 DPI / Stucki mode (i had problem adjusting B&W balance on 600 DPI but image is quite good on 400 DPI )

Lasertile 8" vision series birch white

I get some strange lines while engraving image parts formed by large black areas. You can notice them on attached jpg files.

I have no idea how to correct this and as i live in Turkey / Istanbul i already paid a fortune for getting my lasertile pack I cant easly buy new ones to replace those and my amno is limited.

Thank you

[Margaret Turco]

Hello Onur, Have you tried changing to maybe 80% black in those areas? Are you talking about what looks like horizontal banding? I sometimes have to slow the speed down to avoid that. Good luck, and I hope you will post a picture of your finished project!

[Frank Corker]

Hello Onur and welcome to Sawmill Creek. I'm sure the answer to your problem will be discovered here. You do seem to have a 'banding' problem and the answer might be being caused by the way that you are processing your image. The banding might also be caused as a direct result of the image of the painting that you have and may be a Moiré effect - see here (http://www.mathematik.com/Moire/). Because the workpiece you are doing is going to be huge by anyone's standards, I suspect it will be the graphic itself. If the graphic has been 'blown up' to meet your required size 31"x55" then it is likely that during the processing the program that you used to do it has caused the banding. It may appear to be obvious on the large canvas and not so obvious on your video screen.

I am a big fan of William Adolphe Bouguereau, finest painter that ever lived in my opinion (of which I am entitled to have). His works are amazing. The one that you have there; A la fontaine is beautiful. From your input it would appear that you are just putting the image directly through without using one of the more popular methods such as 'Photograv' or other image processing system. I make that assumption because you have not made reference to it.

I have included in the attached file the same image, with a height of 8" the A la fontaine painting which I have processed using Photograv. I realise that you are doing a much larger version of it, but by doing the full image on one 8" file and comparing it to what you already have, the answer might be immediately apparent.

Either of these two images can be imported directly into Corel and are ready for engraving. You must not resize them in anyway, shape or form. If you do, then my efforts will be wasted as the included images have been specifically done for your size (8"), material (laser tile) and machine/wattage. So import, place and engrave only.

The program tells me that for our machines (45w Eplilog) that the image can be run at 100 power 100 speed, but the latest version does tend to throw out some odd readings. So I have included in this zipped file, one which I have marked 100power x 100speed and I have also included one using the settings that you have originally chosen to use, 65 speed and 60 power. They do look identical but rather than risk there being a difference I have done both, I'm sure that you will find one of them to your liking.

Try these and see if they work for you. I have never been able to get hold of one of these laser tiles so you will have to trust in either your own settings or the ones given by Photograv. Please let us see the results for the benefit of all the members here on the Creek.

[onur cakir]

Hi, thanks for replies !

Well at first try i had a bigger horizontal banding problem on S75 and P60. Than i slowed down to S65 and banding dissapeared a little. In order to keep same B&W contrast i think as i reduce speed i have to reduce power as well. I wonder if there is a direct proportion like if i reduce speed %10 i have to reduce power %10 as well.

Frank you're right. I dont use photograv. To be honest main reason is lasertile is brand new for Turkey market. So it will be presented for the first time on decoration fair and i dont know how architechts will respond to this new decoration component. So i didnt want to invest more $350 before i check the reaction.

Second reason is, for black granite engraving i use gold method. But lasertile is something different (maybe i'm wrong). It acts like a photopaper on a inkjet printer so i think we dont have to change images to 1 bit bitmaps like photograv or goldmethod do. I guess unlike black granite, that special coating they use responds well to laser beams for shades or gradients on 8 bit grayscale images.

I tried to raster with checking 3D settings on advanced tab. On epilog's manual it has been informed that the 3D settings responds to grayscale on images and beams automaticaly different watts for different points to give more grayscale tone change. But it didnt worked well

But sure i will try your files too because i never tried 1 bit bitmaps on lasertile (because i dont have photograv).

The process i'm using is quite simple for image processing. First i open the image on PS CS3 and use black&white tool in image->adjustments and i use "natural density" in default settings. Than import the image to corel x3 and tile it into pieces.

First i thought i'm experiencing a mechanical failure but it looks like Moiré effect now.

Also i had banding much more when i tried to engrave images on 600 DPI. That proves Moiré effect too because as i increase DotPerInch that effect will be much more visible.

So as a result, besides photograv solution i guess i have to use 300 DPI with low speed and power for grayscale balance. I'll let you know the results on both photograv and 300 dpi.

By the way i'm a big fan of Bouguereau too My top three artists are ( besides DaVinci etc. ) Bouguereau, Alphonso Mucha and an Iranian painter living in USA....the great Mahmoud Farshchian, persian miniature master painter http://www.farshchianart.com/farshchian.htm

Attached you will find other parts of A La Fontaine and my other DaVinci panel 31"x39"

You can download bigger size images from :
http://www.decodepo.com/depo/1.JPG
http://www.decodepo.com/depo/2.JPG
http://www.decodepo.com/depo/3.JPG
http://www.decodepo.com/depo/4.JPG
http://www.decodepo.com/depo/5.JPG
http://www.decodepo.com/depo/6.JPG


Thank you

[Lee DeRaud]

Because the workpiece you are doing is going to be huge by anyone's standards, I suspect it will be the graphic itself. If the graphic has been 'blown up' to meet your required size 31"x55" then it is likely that during the processing the program that you used to do it has caused the banding. It may appear to be obvious on the large canvas and not so obvious on your video screen.

What he said.

FWIW, I've been using PhotoZoom Pro (www.benvista.com) when I need to generate very large images: it has some algorithms built-in that seem to work a lot better at high magnifications than the ones in Corel PhotoPaint etc. Even at moderate magnifications, it does some truly miraculous cleanup on things like scanned B&W negatives, in a single pass vs massive twiddling with settings and multiple filters on other software.

(Don't know why they do it this way, but it's actually cheaper to buy their entry-level 'PhotoMagic' program and then upgrade...you can do both in the same order.)

[mike wallis]

Hi everyone !

First of all merry Christmas and happy new year to all.

I'm a newbie on laser business and expert on decoration business

Here is my problem; i'll be on a decoration fair in Istanbul 2 weeks later and i'm prepearing 31" wide and 55" height wall panel from a Bouguereau artwork.

My settings are

Epilog mini24 45W ( brand new )

Speed : 65
Power : 60

400 DPI / Stucki mode (i had problem adjusting B&W balance on 600 DPI but image is quite good on 400 DPI )

Lasertile 8" vision series birch white

I get some strange lines while engraving image parts formed by large black areas. You can notice them on attached jpg files.

I have no idea how to correct this and as i live in Turkey / Istanbul i already paid a fortune for getting my lasertile pack I cant easly buy new ones to replace those and my amno is limited.

Thank you

Hello Onur, I'm on my forth year of full time laser photo engraving with my Mini. I currently have the same model as you except I have a 35 watt. The photo you've posted initially from my experience is a classic horizontal banding issue. The main cause is power fluctuations in the laser tube itself. Most laser tubes have some amount of power fluctuation, some more some less.

Now to analyze the picture that was posted. Notice how the banding starts with tighter patterns at the top then as it goes down the patterns get wider. I've found it's a matter of what temperature the tube is at the time. If the tube is cold or the first job of the day you will most likely get the tight bands as found in your image and as the tube warms up the bands spread further apart. If the laser has just run a job for 15-20 minutes then the banding will most likely look like the bottom of the image with the wider banding. This is less noticeable to the eye because the are spread further apart.

Over the last few years I've learned a few tricks that can minimize the power fluctuations. I call it "Getting the tube in the mood". First I'll run a vector file at 100% power for about five minutes, this will get the laser tube up to tempiture quickly. Next I'll send the job over to the laser that I'm actually going to engrave on the piece and run it without the material in the machine "Dry Run". Make sure the power and speed is the same as what you will be using on the tile itself. I usually only run it for about the first 4-6 minutes. At this point the laser tube temp is at the level it needs to be to run the actual piece. The first vector file got it up to temp and the second leveled out the temp to what will be engraved on the piece.

Please note that this process is only needed when engraving certain midtones. Solid black and lighter shades are not usually an issue. That is why some images have an issue and others do not.

Give these a shot and they will most likely do the trick.

God Bless,
Mike W

[onur cakir]

Lee, you're right about generating big images, i'll compare it with PS CS3

Mike, thats a good idea !!! Almost the same method that i "warm" my bass guitar amp's tubes

My laser works in a cold area, in a balcony fully covered with thick glass and its winter in Istanbul. I guess that can be another issue too..

Thank you !

[Bill Cunningham]

It also maybe something as simple as engraving at a different dpi or odd multiple of the photo dpi if the photo is 300 or 600 dpi, and your engraving it at 400, you can expect some banding particularly at the large sizes you require..

[onur cakir]

It also maybe something as simple as engraving at a different dpi or odd multiple of the photo dpi if the photo is 300 or 600 dpi, and your engraving it at 400, you can expect some banding particularly at the large sizes you require..

At this point i have a basic question ! I set my image to 400 DPI and place image into tiles by powerclip. Than set the laser setting 400 DPI too. Everything is ok but as i check "file->document info" it says 300 DPI !!!!? So am i sending the image on 300 DPI or 400 DPI ??

[Bill Cunningham]

If you are generally working in 400 dpi, you may have to to go into the Corel options and set your working dpi to 400.. Corel defaults to 300 out of the box.. If you are powerclipping the bitmap, Corel may be resampling to 300 so its 300 you would be sending to the laser..You can engrave 300 at 150, 300,600,900,etc.. But 400 would be a odd res. and could be the basis for your problems..

[onur cakir]

If you are generally working in 400 dpi, you may have to to go into the Corel options and set your working dpi to 400.. Corel defaults to 300 out of the box.. If you are powerclipping the bitmap, Corel may be resampling to 300 so its 300 you would be sending to the laser..You can engrave 300 at 150, 300,600,900,etc.. But 400 would be a odd res. and could be the basis for your problems..

so here is another problem i cant change document resolution...its dissabled ! any ideas ? see attached file

if i'll setup a market for lasertile i'll hire a graphic artist first thing

[Phil Garcia]

One thing to remember about the operating temperature for your Epilog Laser. I spoke to the factory about this and they told me to be sure to warm up the laser before firing it if the temperature is below 40 degrees. They recommend running the machine for about 20 to 30 minutes before doing any firing of the laser so that the hot beam would not hit a cold lens which could cause a crack in the lens. You may want to place a space heater near the Epilog for an hour or two if you housing the Epilog in a cold place. Just a FYI..

[onur cakir]

One thing to remember about the operating temperature for your Epilog Laser. I spoke to the factory about this and they told me to be sure to warm up the laser before firing it if the temperature is below 40 degrees. They recommend running the machine for about 20 to 30 minutes before doing any firing of the laser so that the hot beam would not hit a cold lens which could cause a crack in the lens. You may want to place a space heater near the Epilog for an hour or two if you housing the Epilog in a cold place. Just a FYI..

oppps.....ok, thats another thing to remember. Thank you. By the way 40 degrees celcius/Fahrenhayt ?

[AL Ursich]

Nice web site !!!!! Some really GREAT Projects. A inspiration to ALL.

I visited Istanbul in my Navy Days in the 80's. Great Place !!!!


AL

[Dave Johnson29]

oppps.....ok, thats another thing to remember. Thank you. By the way 40 degrees celcius/Fahrenhayt ?

If it is cold, use a night-light on an extension lead. It was 8F degrees (24 below freezing) here at 9:30am the other morning.

During Winter, I have a 5-Watt night light inside the laser cabinet and I was able to start straight up and run yesterday. Costs around $0.07 per week to run. I have them in the control cabinets of the CNC machines too. Either that or I leave the computers running in them.