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Rags Alan Ragland
02-16-2009, 10:41 PM
Hello creekers,
Does anyone know of a site that will "Prepare photos for rastering on marble. I see some of the work you guys/gals do on here and I cannot get close to that level. I have 12 photos I need to put on 6 x 8 marble.
Any ideas as I am in immediate need. All the photos are studio portraits but my ineptness to prepare them is great.
Dr. Rags

Ricardo Gomes
02-16-2009, 10:50 PM
you can use photograv for that ;)

Steve Clarkson
02-17-2009, 12:17 AM
Hello creekers,
Does anyone know of a site that will "Prepare photos for rastering on marble. I see some of the work you guys/gals do on here and I cannot get close to that level. I have 12 photos I need to put on 6 x 8 marble.
Any ideas as I am in immediate need. All the photos are studio portraits but my ineptness to prepare them is great.
Dr. Rags

Alan,

In 6-8 months I'm hoping to be good enough to hang a shingle for processing other people's photos. Can you wait that long?

Actually, if we can convince Dr. Frank to stop lasering and open "Frank's Fotos"........

All joking aside......I would love to be able to e-mail a picture somewhere and have it sent back ready to engrave.

But I have been practicing alot lately, so if you want to e-mail a few of them to me, I'd be happy to run them through photograv for you.....then you can "owe me one". Besides.....I'd rather practice on your stuff than mine!

Rags Alan Ragland
02-17-2009, 3:10 AM
I have photograv but am not as much of a fan as everyone here seems to be. Have run two of them through and am not impressed at all.
I tried to follow Frank's posting of Rodneys system but got lost at "convert to bitmap using 125-150 ppi and a diffusion pattern. (huh)
Dr. Rags

Frank Corker
02-17-2009, 6:03 AM
Rags if you are still running your Epilog Legend EXT36 75W, might I suggest the following. Size and convert your picture to 8bit black and white. Make it a negative. Import it into Corel. Engrave it at 100sp and 30 to 40 power, without processing it through anything. I think you will find you can produce an excellent picture probably even better than through photograv.

Mike Null
02-17-2009, 8:28 AM
Rags

There's a magic tool in PhotoPaint called a tone curve under the effects menu. Play with it for a while and I think you'll find you can work wonders.

Rags Alan Ragland
02-17-2009, 11:25 AM
Frank
Thanks that is exactly what I am doing except at 100sp 30-40 I get a nice white blob. On marble I get a good rendering at 100sp and 8-12p. But I cannot get the defination I see everyone getting.

Mike
Thanks I will play with the "tone curve" as you suggested. When I master it I'll try to post pictures of my results.

Again,
Thanks all of you
Dr. Rags

Stephen Beckham
02-17-2009, 12:13 PM
Dr. Rags,

Pleaseeeee - I don't mean to insult by asking, but are you sure you've got Marble and not Granite?

I've been told I'm crazy, but I can take the same exact photo and put it on black marble, but then I get a big white blob when I put it on granite with same settings.

The little monicle that lasersketch.com sells is invaluable. If you look at your work and see chips versus seeing divits - you've got one of two problems (as I understand) - too much power or dots too close together. I'm not sure of the correct term, but I call it blowout where the power disperses sideways and causes unetched sections between two or more etched dots blowing out as a chip. It will happen in glass, marble and especially in granite.

My 2 cents....

Frank Corker
02-17-2009, 12:25 PM
Frank
Thanks that is exactly what I am doing except at 100sp 30-40 I get a nice white blob. On marble I get a good rendering at 100sp and 8-12p. But I cannot get the defination I see everyone getting.

Mike
Thanks I will play with the "tone curve" as you suggested. When I master it I'll try to post pictures of my results.

Again,
Thanks all of you
Dr. Rags

If you are just getting a blob, decrease the brightness by quite a bit and try again. It will become clearer

Dan Hintz
02-17-2009, 12:39 PM
Also make sure your final image resolution is the same as the one you're engraving at... that was my problem. Even though the image on the screen looked like it had good contrast and detail, the engraved image would come out either washed out or seriously lacking detail. Once I religiously moved to 250 dpi (or whatever you want to use) on both the image and the print driver, the images started to pop.

John W. Love
02-17-2009, 4:31 PM
So, you use the exact same dpi in the image and the engraving? Not just a multiple of? For example, I've been processing my images at 300 dpi, but I've been lasering them at 600 dpi because when I tried them at 300 my nice white background came out with like a halo effect

Dan Hintz
02-17-2009, 8:12 PM
You got it... I haven't done a controlled run of settings yet, but 250dpi seems to work quite well, so I'll stick with it until I have some free time :rolleyes: to try other settings. Make sure you resize and resample (i.e., change the dpi) your image as one of the first steps. If you do so after you've sharpened it, you run the risk of softening the image with an "I'm smarter than the user" resizing algorithm.

Bill Cunningham
02-17-2009, 11:12 PM
Theres black stuff out there thats being sold as 'marble' and it ain't... Real marble is just about goof proof, does not need photograv, and requires high power and low speed.. If you have any doubt, put a drop of acid (sulfuric/battery or muriatic is fine) if it's marble the acid will mar the surface immediatly. If it's something else, it will have no effect on the polished surface and you can wipe it right off.. Even a weak acid will etch marble, I have a piece here with a lovely hand print left by someone eating a orange:mad: If you want to compare, go get a piece of brown marble from H.D. and laser a gray scale 'negative' photo onto it.. (30-40 watts = 30-40 sp/100%pwr) The results should be pretty good, you can tweak it from there

Steve Clarkson
02-17-2009, 11:56 PM
Size and convert your picture to 8bit black and white.

How do you convert to an 8 bit black and white? Is that something you can only do in Photoshop?

By the way, I have Photoshop Elements.....does that count as a watered down version of Photoshop? I've never used it.

Scott Erwin
02-18-2009, 4:32 AM
How do you convert to an 8 bit black and white? Is that something you can only do in Photoshop?

By the way, I have Photoshop Elements.....does that count as a watered down version of Photoshop? I've never used it.

Not sure about PS-Elements, I have PS CS4, sorry, but here are a couple of options for you....

In Corel, import your picture, select it, goto BITMAPS, and select CONVERT TO BITMAP, then goto BITMAPS, and select MODE, select GREYSCALE (8-BIT). This will get you by in a pinch. You now have an 8-bit picture. --

In Photoshop, open your photo, goto IMAGE, and select MODE. Here you will see two parts to the list. The lower one has a choise of three selections to choose from:
8-BITS/CHANNEL, 16-BITS/CHANNEL, and 32-BITS/CHANNEL.
Select the 8-BITS/CHANNEL, this will put a check mark next to it. It will also close the menu.
goto IMAGE, and select MODE again. The upper part of the menu will have upto 8 options. The first option is BITMAP. The second option is GREYSCALE. I use both.

Frank Corker
02-18-2009, 8:03 AM
Steve, you have photograv. Open it in photograv, then save the original as greyscale without any processing.

Steve Clarkson
02-18-2009, 9:01 AM
So when you said "8 bit black & white" you actually meant "8 bit greyscale" ?

In PhotoPaint my choices are "1 bit black & white" and "8 bit greyscale"......I thought that maybe there was some option in Photoshop that allowed you to make an "8 bit black & white".....if such a thing is even possible.

Frank Corker
02-18-2009, 10:02 AM
Steve I meant greyscale. There is 1 bit black and white but you would only be doing that on a flat image. Greyscale is what your laser uses to make a picture. Personally I thought that was a given explanation.

Steve Clarkson
02-18-2009, 10:05 AM
Frank, I hang on your every word.