Photo Lasering 101

The original image before scanning with PhotoGrav.

Copyright © 2004 by Davis Multimedia, Int'l. All Rights Reserved.
As Printed in April 2004, Volume 29, No. 10 of The Engravers Journal.
By Mike Fruciano

     The multi-billion dollar photo industry recently entered the digital age and now it has entered the world of laser engraving. Human nature is to remember the good times and great people in our lives and photography has been the preferred medium for capturing family and friends in all kinds of settings. Our closets are filled with the memories of our childhood, school days, weddings and so many other important events in our lives.
    Customers frequently ask us the question of why they should purchase a new laser system. The answer is a simple one. Modern lasers are profitable because they are very flexible and can work with so many materials. Creating unique products for your customer is a path to success. A photo of a loved one laser engraved on a keepsake has tremendous value to your customer. Think of this old adage, if a picture is worth a thousand words, how much is a photo laser engraved on marble worth?
    The Eastman Kodak Company has become a household name and George Eastman is thought of as the father of photography. Eastman didn’t actually invent photography; however, what he did was create a whole industry by simplifying the process of recording our lives on film. Eastman introduced the Brownie camera in the early 1900s and the world became fascinated with capturing the events of our lives on film to share with others. Today, photography is easier than ever thanks to digital cameras and desktop computers. Our digital snapshots can be sent via the Internet (or even our cell phone) around the world in seconds using powerful computer technology.
    This same computer technology allows us to scan color or black & white photos or to take digital photos and then laser engrave these images on various materials such as marble, wood, leather, coated metals, acrylic and so much more. The process of laser engraving photos is easier than many people realize and can open many new business opportunities that you may not have imagined.


 

The photo after it was scanned as an 8-bit grayscale bitmap. The dpi setting of the scanner should match the dpi you plan to engrave with (i.e. choose 500 or 600 dpi). After the PhotoGrav magic happens. The computer adjusted the variables in the photo and delivered a ready to engrave image.

The Right Tools
    Having the right tools for the job always makes the task easier and our computers are just imaging tools. Working with photographs can require moderate computing power to perform tasks quickly without a lot of waiting. Part of the issue is with slow processing times and with the software used to edit digital photographs.
    Image editing programs like Adobe Photoshop or Corel Photo-Paint take considerable computer resources to operate and can take their toll on a computer’s performance.
    Two rules of thumb apply to speed up a computer crunching on images: the first is having lots of memory available. Editing programs need plenty of swap space (virtual memory) on your hard drive for temporarily storing data as well as Random Access Memory (RAM) for faster display updates and image data storage. The virtual memory settings are best set to “maximum” for optimum performance. The actual value of virtual memory is dependant on the amount of free space available on your hard drive.
    RAM memory is something you can never have enough of in your computer system. Most new computer systems come with 256 MB of RAM which is barely adequate; 256 MB should be the minimum and the optimum range being 512 MB or above. Adding more RAM memory is an easy upgrade to older systems with an immediate performance increase.
    The second rule for fast processing of images is that there is nothing better that pure horsepower in the form of a fast processor chip. High speed computers are now the norm in the 21st century with clock speeds over 2 GHz (two million clock cycles per second) available in computers from your local retailer. Providing your system has plenty of memory, a 1.0 GHz computer system is capable of timely computing processing while a 2.0 GHz or higher system will have no problem with the largest of file sizes.
    The next key component is the scanner, which will be a large factor in determining the final image quality. A major brand name flat bed scanner with a 600 x 1200 resolution will be capable of just about anything you’ll ever need to reproduce. Some computers now support USB (Universal Serial Bus) communications for easy connections and fast data transfer. Having USB capability is an excellent feature for a scanner, making it both easy to install and to operate.
    Other scanners interface using a parallel cable which hooks up to the printer port on your computer. This can sometimes cause interference with other devices like your laser printer or laser engraving system. Most of the computer equipment manufacturers like to keep things interesting by making older systems obsolete, so if you’re shopping for a new scanner for an older computer system, verify that the scanner is compatible with the operating system.




The completed PhotoGraV image engraved on a black marble plaque.   Applying CerMark Metal Marking Solution to a tile.

Lasering Photos
    The laser engraving system works like a regular black and white printer, so preparing a photo for engraving is almost identical. However, several variables exist in the process of laser engraving photos. To achieve the best results, consider all of these variables and try to reduce their impact on your engraving work.
    Start by considering the original photo you’re scanning. The best photos to scan have detail in the dark areas (shadow) and in the light areas (highlight). Since all photos are scanned as a black & white image, it doesn’t matter if the original photo is color or black and white. Typically, you won’t find the photos supplied by customers that have good tonal range and some adjustments will need to be considered.
    Next, consider the resolution settings and lens on your laser system. For best results set the dpi resolution settings in the print driver to a mid-range of 500 or 600. Engraving photos at any resolution setting below 500 or 600 dpi will result in too many jagged pixels and the engraving won’t have smooth gradations between dark and light areas. Be sure to use a focus lens with a focal length of 1.5 or 2 inches. These lenses will generate a small laser spot size needed for clear, defined engraving.
    Selecting the material to engrave on may also have an effect on the quality of engraving. The most dramatic results for a photo use a material that will have excellent contrast when the laser engraves. Some materials that work well for this application are acrylic, marble, wood, leather, coated metals and anodized aluminum. All of these materials react differently to the laser and some adjustments to the scanned photo may be necessary to achieve best results.
    The final variable is deciding the type of dot pattern to engrave. The two types most commonly used for this application are Diffusion and Halftone patterns. A Diffusion pattern is a variable dot pattern that produces a photo realistic result. A Halftone pattern is a series of larger or smaller dots that create the look of a photograph. The Diffusion pattern generates a pleasing look on almost all materials whereas the Halftone pattern looks best when lasered on wood with deep engraving.
    Based on these production variables, you can consider which process to use when engraving: the Manual Process or the Automatic Process.



A completed plaque with a Shuttle image created with CerMark Metal Marking Solution and TechLine stainless steel.   The Tile Marking Solution can be applied to any tile (not just tiles specifically for laser engraving) to create a very permanent black marking.

The Manual Process
    The Manual Process of lasering photos is a good one and uses the print driver of your laser system to generate the halftone or diffusion dithering patterns. Start with scanning the photo at 300 dpi as a black and white photograph. Scanning the photo can be done using the “Acquire” function in DRAW or Paint or by using the standalone scanning program that comes with the scanner. Most of the time I scan several photos at once and prefer the simplicity of using the standalone software. The scans are automatically saved in my Temp folder and later I will put them in the Recycle Bin, after the engraving has been completed.
    After scanning, open the photo in Corel PhotoPaint or Adobe PhotoShop to resize or customize it for laser engraving. A quick method to scale the photo to the correct size is to use the “Resample” tool. After selecting “Resample,” enter the finished engraving size needed and the program will adjust the size. Adding a vignette look to the image will add a professional looking flair to the finished engraving. Select the “Circle Mask Tool” and draw an oval around the subject. Adjust the “Feather” feature to 20 for a nice blended edge effect. If the photo is to be engraved on the back side (second surface) of acrylic you can use the “Mirror” tool to modify the photo so it’s right-reading from the front side of the acrylic piece. Some acrylics also have a painted surface so you may need to use the “Invert” function so the image views as a positive. Now save the modified image area as a new object in a special folder and you’re ready to engrave!
    Import the enhanced photo into CorelDRAW and print it to the laser as you would a normal graphic or text. The print driver settings vary from make and model but in general the laser will see the photo as a bitmap. The print driver will convert the bitmap into a dithered image for laser engraving. A dithered image is one that simulates gray tones by spacing black and white dots. A quick reference to your operator’s manual will confirm the exact print driver settings for your specific system. Set the dpi setting in the driver to a mid-range value of 500 or 600. Using a higher dpi setting will create a small increase in the visual quality of the engraving and an increase in the run time of the job.
    The final step is to adjust the power and speed settings, which should be set in the print driver for the black color only. Use the normal power and speed settings as if you were engraving text or other graphics on the specific material. Load the material to be engraved into the laser system and check for correct focus.
    Most of the time the engraving quality will be excellent. In case the quality of engraving needs improving, try modifying the tonal range of the scanned image. Usually the most difficult photos to engrave have low shadow and highlight detail. The laser engraving process adds contrast to the photo and results in blocked in areas that don’t look like a photo. Your editing program (PhotoShop or PhotoPaint) has a tool called “Tone Curve” that can adjust the shadow and highlight areas for improved engraving quality. After adjusting the Tone Curve of the photo, engrave it again and compare the results.


 

 

 

The finished tile created with Tile Marking Solution.
 

The Automatic Process
    Since “necessity is the mother of invention,” a new process for laser engraving photos was developed several years ago to improve the productivity of the manual method of processing. The idea was to create a software product that removed all of the variables in the process and was simple to operate. The result is a software product called PhotoGrav, which is designed by laser engraving experts for laser engraving. Our customers rave about the results using PhotoGrav software and it’s always a main topic at our Laser Workshops. The automatic process of engraving photos is as simple as 1-2-3.
    Step one is to scan the photo as an 8-bit grayscale bitmap. The dpi setting of the scanner should match the dpi you plan to engrave with (i.e. choose 500 or 600 dpi). Use the automatic controls in the scanner to adjust for an overall good brightness. Size the image to the final engraving dimensions. Apply a vignette oval or any other special effect to the image at this time.
    The next step is to open the scanned bitmap in PhotoGrav. Now select the material to be engraved from a list of 19 different materials. Click on the “Auto Process” button and watch the magic happen. Your computer is now adjusting for all the variables in the photo, the laser system and the material to be engraved. After a short processing time, you can save the processed image in a special folder.
    Finally, import the processed image into CorelDRAW and you’re ready for engraving. If you chose a material in PhotoGrav for second surface engraving, the processed image includes all of the modifications needed. This is a great feature, as I usually forget this step when I use the manual process and have to engrave a second piece to fix my mistake.
    Based on the results from customers around the world using this product, we can safely say that almost every job processed using PhotoGrav will give first run results. What really makes this program so effective are the processing modules that calculate far past the capability of any laser system print driver. These detailed modules have advanced processing for generating highly accurate diffusion dithering and halftone patterns, gray shade mapping for highlight and shadow detail enhancement, and even a simulation mode to see the enhanced image before engraving. These and many other features operate automatically when the Auto Process button is clicked. Each module has adjustable features for detailed tweaking of the features for top performance.
    Many customers successfully use PhotoGrav software in a production environment by standardizing the photo engraving process. For instance, a group of photos are scanned without special attention to each one and then stored in a folder on the hard drive. Each scanned photo is opened in PhotoGrav where it’s processed for the specific material to be engraved and then saved into another folder. These processed images are imported into CorelDRAW and either laser engraved individually or as a group for maximum productivity.
Expanding Your Products
    Surely, your customers ask you the same question every year, “What’s new?” Each year you go to the trade shows to see new products and machines so you have an answer for those customers. Continually having new products is a key to having customers return year after year and is a proven method of success in business.
    A personal photo is a memory of lifetime that we all would like to preserve and now it is feasible and profitable to bring these products to your customers.
    This year when customers come into your shop, you can show them a product that really is new, laser engraved photographs.


 

 

 



Materials for Laser Engraved Photos

 

 

 


Acrylic
    Cast acrylic is an excellent medium for laser engraved photos. It’s available in sheets and shaped products for unique gifts or plaques. Painted acrylic makes photos look deep and high quality.
Anodized Aluminum
    Simple and easy to work with, anodized aluminum provides excellent contrast and detail for photo engraving. Sheets of aluminum can be easily sheared to standard photo sizes for inserting into photo frames.
Coated Metals
    Lacquer coated brass makes an elegant material for photo engraving plaques. Polished or brushed stainless steel creates a unique look when laser engraved using Cerdec Metal Marking Solution.
Engraving Plastic
    Cost effective and easy to engrave or cut using the laser, engraving plastic sheet stock is a natural for detailed photos.
Leather
    Light colored leather looks rich and elegant with old family photos engraved creating a unique family heirloom.
Micro Surface Plastics
    Materials such as Spectrum Lights are ideal for finely detailed photos and have a self-adhesive back for application to many base materials.
Marble
    Jet-black marble creates beautiful contrast when laser engraved and will make a lasting gift when personalized with a photograph.
Wood
    Woods such as cherry and alder laser engrave with outstanding detail and create an interesting natural look when engraved with wildlife and portrait photos.

 

 

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