PDA

View Full Version : Has anyone tried this with Photograv? Secret!



Jason Smalling
05-21-2008, 12:04 AM
Hello, everyone! I have been using photograv and been using the settings they suggest. I have a pinnacle m series laser and it has a print driver. The setting options are black and white, manual color fill, 3 d and stamp mode. The raster tab pops up only when the black and white option is checked. It then has halftone, stucki, jarvis...etc. Photograv suggests having it on black and white, then on the dithering option and jarvis or stucki selected. I always wondered why since photograv is putting the picture into a dithering format to begin with. It is like having dots within dots. So I tried manual color fill option with the photograved picture. So everything black would be lasered. Like the black dots, instead of dots being broken up by other dots. The photo turned out beautifully. 1000% better than the black and white mode. Tried it on several materials and it works better on all. Anyone else found this little tip...your thoughts and suggestions welcomed! Thanks everyone!

Darren Null
05-21-2008, 12:10 AM
I have a GCC Mercury- same thing. I tried the black and white mode once when I got the machine, and it was so crap it's been set to manual colour fill ever since. Never thought to mention it though. Good one!

Rodne Gold
05-21-2008, 3:02 AM
Photograv does what the driver does , it converts everything to black and white dots , does the correct dithering and so on , so if you use photo mode , all you are doing is Re processing the correct file.......zoom in in Corel on your photograv bitmap , you will see it is NOT shades of grey and thus using photo mode for any machine is totally counterproductive.

Vicky Orsini
05-21-2008, 11:01 AM
Thank you for posting this! I've been wondering if it's just me, being Photograv-challenged. I'll give this a shot before putting my copy of Photograv on E-bay. :D

Darren Null
05-21-2008, 11:44 AM
What's the problem? I've got a generic routine that works quite well for pretty well everything:

1) Open the image in a graphics editor. Photoshop in my case. Crop to get it the shape you want.

2) Remove any bits you don't want. If you're doing a portrait of someone, for example, the background is often distracting and unnecessary.

3) Resample it to the size you want. The actual size it's going to be on your object at 300dpi (150dpi for glass)

4) Save the file s an 8-bit (greyscale) BMP file.

5) Import the BMP into photograv. I just use the cherry setting for everything. Seems to work. Run it through and save the engraving file. Ignore the preview.

6) Import the engraving file into coreldraw. Speed & power suitable for the material; set your driver to 'manual' (ie, don't do anything to the picture...manual colour fill on mine it may be called something different on yours).

7) Burn.

Hope there was something useful in there.

Vicky Orsini
05-21-2008, 12:16 PM
Darren, it's step 6 - the part about "set to manual" - that seems to be causing the problems. I'm going to give it a shot this afternoon using the manual setting, instead of the system's default settings.

Question: How do you keep an almost-white dog from looking washed-out?

Darren Null
05-21-2008, 2:00 PM
The set to manual bit is on the laser machine print driver (for me, anyway). Not the Corel print settings. My driver has a couple of different options: 3D; stamps; black and white (adds dithering, but badly); manual colour fill. the latter is the 'just leave it alone and burn what I tell you to' setting.

Question: How do you keep an almost-white dog from looking washed-out?

If you're just working on the photo, try:
Contrast up, brightness down.
Removing the background.
Unsharp Mask (although Photograv will do this too, so don't overcook it)

If you're taking the photo, try turning the flash off and lighting from another angle, if possible. Better yet, take a few photos outdoors.
White dogs and flashguns are a bad idea, because the light is coming straight back at you and you lose all the detail...also, your camera will be trying to take a balanced whole image, and a big white blob in the middle will tend to wash out. If your camera has a manual override, you can look through the viewfinder; see what your camera wants to take the photo at and then either use less aperture or less exposure time (on full manual so your camera doesn't compensate for your adjustments).

Outdoor pics are easiest. Slightly overcast day would be perfect if it's a bright white dog. Flash off and lighting from the side will work too. If you have a white wall, photograph the dog against that. That'd work too.

John Bowden
05-21-2008, 2:07 PM
I rarely bother with cropping the image to shape.
For the granite 5 x 7 ovals I did lastnight...
I resampled the picture in photograv to the size I needed (5 x 7).
In Corel Draw I made a 5 x 7 ellipse and vector burned it on to a piece of cork.
Then I placed the piece to be engraved inside the vector shape on the cork.
I Imported the bitmap, moved the ellipse to the front, and change the properties of the ellipse to color: white and line width: 24 point (or 16 pt depending on the material's edge properties).
NOTE: DONĒT MOVE THE ELLIPSE!
Itís fast, easy to align, and it leaves a nice clean edge (no engraving on the bevel). And the cork template is cheap and reusable. It's always worked for me.

Ray Rouleau
05-21-2008, 6:25 PM
Jason would it be possible to post some side x side pics, would be interesting to see the difference. I'm also having some difficulty with photograv, but I'm also very picky.

Richard Rumancik
05-21-2008, 10:45 PM
To clarify this thread, Jason and Darren both have GCC Mercury/Pinnacle machines. I am not sure how Jason's comments apply to other machines as the drivers may be quite different.

For the GCC style machine, you can pick "Black and White" or "Manual Color Fill" mode (plus a few more). These terms are a bit confusing. "Black and White" is used when you have a COLOR or GREYSCALE clipart/image and want the laser to do the conversion to B/W behind the scenes. You have a few choices as to how it converts.

If you already have a Black and White image (PhotoGrave, or created in Paint) then you want to use "MANUAL COLOR FILL" mode.

This is what the manual says:


A-1 B/W (Black & White) Mode‑
It is useful to activate this mode when using ClipArt or drawings with several colors, shades of gray, or many outlines. This mode will create a laser output similar to that of a laser printer. The entire selected image will be engraved using a single pen, black one (power & speed setting). The Mercury driver will interpret colored and shaded areas as different shades of gray / halftone areas will be a collection of dots. The resolution and depth of these halftone areas can be adjusted with the DPI, the B/W mode dithering settings from 2x2 to 8x8, error diffusion, and pattern type Experiment with these different settings to get the results.

A-2 Manual Color Fill Mode
Each power and speed setting can be linked to certain color on the layout. Totally 16 color settings are available. The desired color can be adjusted by changing the ratio of Red, Green and Blue. If the speed or power is set to 0, the corresponding color area or vector line will be invalid.
In the older Mercury manual they seem to admit that you will get better quality by doing b/w conversions in Corel PhotoPaint than by letting the laser do it. I don't use the B/W mode for my Mercury at all. I do all my conversions in Paint or PhotoGrav (then use Manual Color Fill mode).

There MIGHT be a parallel to these settings for Epilog, ULS, etc. But the original post refers to a specific option in the GCC driver, not a setting in Corel or PhotoGrav.

Darren Null
05-21-2008, 11:48 PM
Yes, it was all a bit machine specific. Thanks. There's also a 'photo mode' on whatever Rodne is running that you shouldn't use if you've photograved. Same thing presumably.
Maybe we should compile a list of full manual modes for this thread. Settings to use with Photograv (or whatever dithering we happen to be using at the time)

GCC Mercury/Pinnacle machines= 'Manual Colour Fill' in the Machine's print driver dialogue.

Rodne Gold
05-22-2008, 3:24 PM
Im using a GCC , but photograv only gives you black dots , so whatever you would use to engrave black text or black graphics on your machine is what you use for photgrav output.

However , considering there is no greyscale on a photograv output file , you shouldnt actually see in difference (in theory) if you do use a photo mode as there is nothing to convert to halftones , where you might see a difference is the way the photo mode sees a black square (the photograv "dot" , it might try to round it or if you reduce resolution as it would perhaps choose to clump discrete dots

In practice , the driver might decide to do other funny propriety type stuff.

Mark Cline
05-01-2017, 9:19 AM
Just wondering... if you have to do all of that what would be a good reason to get photograv. I have been looking to purchase it.

Tim Bateson
05-01-2017, 9:38 AM
Just wondering... if you have to do all of that what would be a good reason to get photograv. I have been looking to purchase it.

Depends - without a signature, I don't know which machine you are using. If Epilog don't waste your money. Any other laser - may help to some minimal degree.