Photograph Issues

[Sylvia Mossbrucker]

I am using an epilog 120 watt laser and just started using the photograph setting vs. the clipart setting and on all the photos I try to laser onto lasertile im getting a terrible result on the parts of the face that are more washed out. It looks like peeling. Not even anything close to what it should be. anyone have any ideas why this is happening? Im lasering at 50 power 100 speed and 300 dpi

[Darren Null]

If you have a results photo, that'd help with diagnostics. I don't know about Epilog, but the GCC photo/bw setting sucks hugely. I use the full manual setting on the machine and let photoshop/photograv do the number-crunching on the photo.

I *suspect* that the photo setting is only capable of differentiating between a certain number of tones, so if you have areas with continuous gradients -like faces- it's splitting the face into areas with a "that bit's tone 1, so we'll use this pattern of dots; that bit's tone 2, so we'll use this slightly different pattern of dots"...and so on. Thus giving you a 'paint by numbers' effect.
If that is the case, the cure is to run the image through photograv and set the machine to 'don't touch the graphic, I know what I'm doing'.

Without a photo it's difficult to tell though. Just guessing.

[Peck Sidara]

If you have a results photo, that'd help with diagnostics. Agreed, would be very helpful.

A few notes/suggestions:

The better the quality image is to begin with, the better the results.

Photograv and its settings may be useful here.

Try adjusting brightness, contrast etc. thru Corel.

Photograph setting in driver is helpful, it changes the dithering pattern of the image to help enhance the look. However, it's not a magic button.

300DPI is ideal for photos, what happens if you decrease the power?

Post a pic, I'm sure we can offer suggestions at that point.

[Sylvia Mossbrucker]

well i have tried a number of times to get a descent photo from photo grave also and can never seem to have it look descent. what am I doing wrong with photograve because everyone suggests using photograve and photoshop however im just not that experienced in either. any photo ive done in photograve has looked like a drawing or etched photo it doesnt look realistic at all. so if there is any suggestions on that you can give me i would really appreciate it.

[Sylvia Mossbrucker]

i tried to get the pic to show how the nose and forehead are just weird looking and I assume its becasue they are lighter areas hope this helps

[Darren Null]

Right. The first thing you need to be doing is to make sure that you're feeding the program a decent quality photo. If you're burning, say 5" by 3", then you want your input image to be 5"x3" at 300dpi. So your image would need to be (5" x 300 = 1500) x (3" x 300 = 900) so 1500 pixels by 900 pixels. For that size, as long as you have an image that is 1500 pixels by 900 pixels, there'll be enough photo information to give you a good burn.

Into Photoshop. If you're using Photograv, there's not a lot to do in Photoshop; just crop until you're happy with the size, delete bits of the background that you don't want; that sort of thing. Save as an 8-bit BMP file (for Photograv v2.11...not sure about V3).

Into Photograv. Assuming that you've filled in all the bits about your machine, just use the cherry setting and press 'go'. That works for most applications. Save the 'burn' image (I don't bother with the 'preview' image).

Into Corel. Put your graphic where you want it, switch your laser driver to 'manual', get your power and speed right and press 'go'.

Et voila.
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EDIT:

That is quite strange. Can you put a crop of the original nose up? It's hard to see what is going on there. The only thing I can think of without the original; is the original image being awful and that's the laser's impression of JPEG artifacts. Either that or the girl chases tennis raquets for a hobby. It's quite smooth around the eye and the mouth, but seems to be going horribly wrong where the highlights should be.

[Scott Shepherd]

I can't speak for all, because some have good luck, but my problems with Photograv are that the image (on granite) can look like total crud up close, like you're looking at it in the photo. In my opinion, it seems to be more for images that will be viewed from some distance. Take a few steps away and see if you still feel the same way.

Of course, I have seen some amazing Photograv stuff, but most of the amazing stuff was done with a 1.5 lens, or the High Density Optics System on the ULS.

I've never been happy with anything I burned on granite, up close.

[Bob Perdue]

I believe you are using too much power. I have a 30 watt and laser photos on marble at 100 speed and 40 power. With you using a 120 watt laser I would cut the power way down.

[Sylvia Mossbrucker]

if I cut the power down the image doesnt show up at all im using 50 power now and anything less whites the image out completely and im not lasering marble im lasering lasertile (ceramic)

[Sylvia Mossbrucker]

****why Does Everyone Use The Cherry Setting In Photograve?*** Do You Even Use That Setting For Marble, Granite And Ceramic Tile???****

[Darren Null]

Me? Because it seems to work on everything I've tried so far and I'm too lazy to try every single setting. Marble, tile, granite, yep.

EDIT: Does the original image have 'wrinkly bits'? I've deliberately saved this image badly, so you can see what I mean. The wrinkly bits are JPEG artifacts, caused by saving a JPG file with the compression on too high. That could be what your problem is. The only other that springs to mind is that -having processed the photo with Photograv- your laser driver is giving it another unnecessary processing and causing an interference effect. From what I can see of the results, JPEG artifacts are still my best guess.

[Frank Corker]

yep! Definitely jpg artifacts. They are a nuisance at the best of times. Some noise suppression programs such as 'PureImage' will remove those without too much problem.

[Mark Winlund]

I haven't heard andromeda's software yet mentioned. Their screening software is quite useful, and is used with photoshop. I have been impressed with what I can do with it. No need for photograv at all. PhotoGrav has eliminated traditional screen patterns in favor of stochastic screening (they don't mention this in their advertising!). (Stochastic = same size dots, random positioning to simulate grey scale). The andromeda products provide a full range of patterns including the traditional halftones.

Mark

[Darren Null]

Mark,
a while back, we did a (limited) comparison between a few ways of rendering an image down to black and white (not greyscale!). Tested were Andromeda's Etchtone, Photograv, the Graphic Pen filter in Photoshop and Flaming Pear's India Ink.
http://www.sawmillcreek.org/showthread.php?t=79496

I don't have screens installed, and the demo didn't want to co-exist with Etchtone. If you'd care to add a Screens version of the test graphic, I'd be very interested to see how it stands up.

So far, Photograv is in the lead.

[Bill Cunningham]

I can't speak for all, because some have good luck, but my problems with Photograv are that the image (on granite) can look like total crud up close, like you're looking at it in the photo. In my opinion, it seems to be more for images that will be viewed from some distance. Take a few steps away and see if you still feel the same way.

Of course, I have seen some amazing Photograv stuff, but most of the amazing stuff was done with a 1.5 lens, or the High Density Optics System on the ULS.

I've never been happy with anything I burned on granite, up close.

The generic granite setting from photograv seems to give good results.. You can download it from their website.. The attached stone is a 6x10x2" lasergrade abs. black done with the photgrav granite setting..

[James & Zelma Litzmann]

****why Does Everyone Use The Cherry Setting In Photograve?*** Do You Even Use That Setting For Marble, Granite And Ceramic Tile???****

We do not use just the Cherry settings in Photograv, it depends on if when something is engraved, is it going to turn black or white. We come closer to using the "White/Black - IPI Laser Plastic" or "Black/White - IPI Laser Plastic" for most of our jobs, but we do more photographs on mirrors than anything else with Photograv. We have tried granite but we haven't been able to get our setting right either. Not that I was any help at all, just to say, try some of the different settings, you never know which one will work for you & your laser. Good luck.

[James Mooney]

.. The attached stone is a 6x10x2" lasergrade abs.

Hi Bill
Where do you source these blanks?

[Daniel Cline]

I use the "Generic Black Granite" or the "Black Granite 300dpi" param and the black painted acrylic, just remember to say no to reversing the image.

It seems your problem is the image going in though. Etching on black granite is simple as long as the imput image is good.

Herer are a few of mine.

[Bill Cunningham]

Hi Bill
Where do you source these blanks?

Sorry for the delay in answering this, I've been Out and about on the boat!

The stone itself comers out of China, But I bought this particular piece from Richwood In Elora Ontario Canada
http://www.richwoodline.com (http://www.richwoodline.com/)

Don't know if they ship to Ireland though!