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View Full Version : Photograv looks terrible...can someone please walk me through it..?



Garrett Nors
07-06-2009, 12:14 PM
:(

So I got Photograv a while back (before the new one came out) but since the day I've had it I have had no luck with it at all.

I don't know what I'm doing wrong...if the parameters are set incorrectly or what. I always do Interactive (that's what everyone says to do) but no matter how much I tweak it just never comes out well.

In fact, it looks better for me to put a grayscale image directly into CorelDRAW and send it as-is than it is to run it through photograv and then pop it into CorelDRAW.

I always resample my images to match the DPI that my substrate calls for. I always try to get nice, contrasty images that won't bleed out (even though they always do). I always try different parameters in photograv and different speed settings and power settings on the laser but it never works!

Would someone be so kind as to walk me through this? I should be a big enough boy to walk on my own but sometimes you just gotta fall on the floor and cry like a baby :D

All I really need is a starting image (off google or whatever), then the modifications you would do to the photo, etc, till it hits the engraver. Every little step helps.

I have a 45 watt Epilog Helix if that helps.

Thank you! :p

(Also, I have searched this fairly exensively but I can't find a full tutorial of sorts)

Tim Bateson
07-06-2009, 12:18 PM
Since you have an Epilog & I'm assuming using the latest drivers, then use the Dithering options built into the Driver You'll find you have very little use for PhotoGrav.

However if you insist then... 1st rule - NEVER resize even a smidge after PhotoGrav. Stick with the Cherry settings. Set your engraving DPI a little lower then your PhotoGrav DPI.

Garrett Nors
07-06-2009, 12:32 PM
Since you have an Epilog & I'm assuming using the latest drivers, then use the Dithering options built into the Driver You'll find you have very little use for PhotoGrav.

However if you insist then... 1st rule - NEVER resize even a smidge after PhotoGrav. Stick with the Cherry settings. Set your engraving DPI a little lower then your PhotoGrav DPI.

If I didn't have to use PhotoGrav again I wouldn't be dismayed. :D

Dithering...I'll check that out.

Thanks Tim.

Shaddy Dedmore
07-06-2009, 12:47 PM
Which part doesn't look good... just the image, or the final engraved product?

If it's just the image, try actually engraving it to see the true result. I tend to let my laser do the work on marble and lasertiles, but use Photograv on wood and granite.

Shaddy

Garrett Nors
07-06-2009, 1:01 PM
I have spent many hours and many tiles/wood sheets/plastic sheets/metal sheets trying to figure it out and the final product never looks good to me. It's always very washed out and faces are unrecognizable...

Larry Bratton
07-06-2009, 2:34 PM
Garrett:
The secret to getting good results is to start with a high resolution file. By high resolution I mean 300dpi. The old adage "garbage in-garbage out" applies here. A low res image of 72-96 such as downloaded files prepared for the web never give good results.
I normally use Photoshop in conjunction with Photograv to change the contrast and the like. Once I have done that, I change it to a greyscale image before sending to Photograv. And, as Tim said, once you import into Corel, it's OK to move the image around, but don't stretch it or tinker with it at all.
Hope this helps a bit.

Richard McMahon
07-06-2009, 10:10 PM
Hi Garrett,
Check to see weather you have your machine settings right in the "file" drop down menu at the top of the screen. When I first set mine up I stuffed up the machine specifics in the setup right at the start of the installation of the program. This is where you set up the software for each specific machine you may have and the power, dots per inch, beam width and turn time (whatever that is). it took me a few months before I finally figured out I had not set this up properly and felt disgruntled.

I use beam width of 0.004" and dots per inch of 300 and laser power of 30 watts (which is my 30 watt ULS laser tube)
This should get you in the ball park. You may have to uninstall then reinstall the program to do this. Then just resubmit your serial number to register again. It's nice to start off with a clean install sometimes to get back on track.

Set your file size to 300 dpi and what size you want to engrave at. This is actually best set in your processing program like GIMP, Photoshop, Corel Paint etc before you import into Photograv.

After you have loaded your picture and set it's quality/size select "Cherry with light vertical grain" in your "materials" selection drop down menu. Most people seem to use this for all their settings then adjust the sliders to suit the picture.

Then go to the interactive mode and play with the "Extent" slider and the "gray scale" slider on the left adjusting the gamma slider to suit (the middle one). Some people also set the right most slider to about 195 but I don't seem to worry about this too much favoring the gamma slider for most of the adjusting and setting between 3-4. Experience will dictate this.

Your picture should look really washed out and very light if you are engraving on wood, glass etc so zoom in to see individual dots on a face to check what it will look like and alternate between "engraved" and "simulated" screens using the buttons at the top of each screen while in split screen mode.

If you engrave on Granite then it should look really dark. You will have to set this up yourself for the best look and this is where your experience will come into it.
Above all......read the instructions that came with the program and this will help to get you up to speed. Also check out the Photograv forum for more information.
Come back to the creek if you have any more questions.
Hoping this helps.
Rich.

Gary Hair
07-07-2009, 7:41 PM
I always do Interactive (that's what everyone says to do) but no matter how much I tweak it just never comes out well.


I have NEVER used interactive, always automatic and my images have been very acceptable. As someone else mentioned, you must adjust the image first to get lots of contrast - it won't look right this way but it's what PhotoGrav needs, lots of contrast.

1. Open image in PhotoPaint
2. Convert to grayscale
3. Adjust contrast
4. Save as .bmp
5. Auto process in PhotoGrav
6. Import into Corel Draw
7. Print (laser)
8. Collect your money...

Contrary to popular belief, you can edit the resulting image from PhotoGrav and you can resize to some extent. Don't rotate or skew it though. If you want to see the results all you have to do is resize it in Corel Draw and look at the dots - they change size, that's all. If you have a .003 dot and you enlarge to double size, they will be approx. .006. Whether this will damage your image depends entirely on the image.

I had an image that I was testing last week - I lasered it once without any changes and then at double size. The image looked identical, just twice as big. If you need the image twice as big you would be better off enlarging it before PhotoGrav, but it will work either way.

Gary

Bill Cunningham
07-07-2009, 11:20 PM
Photograv also includes a number of sample files.. try those.. as has been said, you need a high res grayscale photo at least 300 dpi if the sample photo is not 300 but rather 400, then re-sample down to 300 for the epilog using photopaint and save as 8 bit grayscale.. Then just process the file using the cherry setting in automatic, save, (it will now be a 300 dpi mono file) import into corel and engrave 'do not change the size' after processing, and for a 45 watt machine, try 35-40 sp 100power 300 dpi (for darker burn use 600 dpi) into any birch ply and see what you get when using the sample bmp's that come with photograv.. If they burn ok, then your problem is in the original photo, before processing.. If they don't burn OK, then you may have an alignment or focus problem, or inadvertantly somehow converting it back to a grayscale from a mono or something weird like that.. Photograv is like a automatic transmission input the right fuel (picture) and step on the gas..

Garrett Nors
07-08-2009, 12:29 AM
Thanks everyone, this thread has been a really big help, I'll be testing like whoa this weekend.

Thanks again!!

Miguel Pinho
07-08-2009, 4:55 PM
When you set the image on corelpaint, use sharpen tool in the maximum (97 to 100) and than do unsharpen mask tool to the middle...save as bmp and import the image to coreldraw to do the layout. See the results and post a photo here so i can see the results.
You can use also GAMA tools on corel paint (1,4 or 1,5 maximum).
When opening the image on corelpaint set the image for 300DPI and resize it proportional.
I use laser power 30% with CAMTECH L5.
Try it
I use this settings when i engrave on black granite tiles.


Hope to help

Regards

Miguel Pinho