Frequently Asked Questions

Large Format Scanners

What is the difference between CCD (Charged Coupled Device) technology and CIS (Contact Image Sensor) technology used in large format scanners, and which is best for my application?
CCD Imaging (Charged Coupled Device):
This method of scanning involves capturing images through the use of a series of cameras that are spread out across the scanning area. These scanning systems use a fluorescent light source and a series of mirrors to reflect light from the surface of the document and pass it to the camera array. The number of cameras will vary depending on brand, model, and scanner width. These systems are also very sensitive, and require calibration from time to time as atmospheric and environmental factors can throw the camera alignment off. The main calibration that needs to be performed is a stitching calibration which aligns the areas where camera fields intersect. Color and white point calibrations generally required for these scanners as well.

CIS Imaging (Contact Image Sensor):
This method of scanning involves capturing images through the use of light reflected off of the surface of the document on to a silicone light sensing array. The silicone sensors are divided into individual sensing cells, and the size and density of these cells determines the optical DPI of the Scanner. The illumination for these Scanners is produced by Light Emitting Diodes (LED) pulses that are directed along surface of the document, and then on to the sensor. Color CIS sensing is produced by rapidly pulsing red, green and blue LEDs. Because there is no color filter used, the color gamut (range of the color spectrum that the scanner can capture), is generally somewhat less than that of a CCD scanner. One big advantage to these Scanners is that they do not require a warm up period like CCD scanners do.

Which Technology is right for me?
This question is somewhat dependent upon the application that the scanner is being used for. A good way to make this determination is whether you need to capture color at a high resolution and with a wide and highly accurate color gamut. If you really need high end graphics resolution, then a CCD Scanner is what you should be looking at. If you primarily scan line drawings, blueprints, or any other document that does not require high end graphics resolution, then you may want to consider a CIS Scanner. CIS Scanners require less calibration, will maintain calibration longer, are very effective and accurate machines for most scanning applications.

What is DPI, and what is the difference between optical DPI and interpolated DPI?
What is DPI?

Dots per inch (DPI) is a measure of the resolution of a scan or print. In other words, it is a measure of a scanner or printer’s accuracy based upon how many individual dots can be read, or printed within a one square inch area. There are two main ways that DPI is used in the industry, and the difference between them can be very important. There are other considerations that weigh into a machine’s DPI capabilities such as scan/print speed, and other various driver settings. Optical DPI (or true DPI) is a measurement of how many dots per inch a scanner/printer is capable of handling without digitally changing the scan and/or print.

Optical DPI:

Optical DPI is generally considered to be the most accurate measurement of a scanner or printer’s capabilities. Most large format scanners and printers will have a DPI range from 96 up to 600 DPI.

Interpolated DPI:

Interpolated DPI is a measurement that refers to images that have been re-sized. When an image that is 600 optical DPI is blown up, the DPI needs to be interpolated by software in order for the image to retain integrity. This means that the software will expand the image, and then go through the image and fill in the white space that is created between the dots when the image is expanded. Interpolated images, while a good concept in principle, lack the accuracy and definition of non interpolated images. Interpolated DPI is often what manufacturers list as the product’s DPI in order to make the product appear more capable than it really is. If you are unsure as to which DPI information you are looking at for a particular product, we can help you accurately assess the machine’s capabilities.

DPI and Scanning Speed:

Scanners usually list the speed capabilities of the machine in their sales materials. Generally, scans that are conducted at higher speeds will see a reduction in resolution quality. However, this does not mean that using the slowest setting will necessarily give you the best possible result. Most scanners will have an optimal threshold that will produce quality scans. We are happy to make recommendations as to optimal operational parameters based upon the scanner, scanning technology, and documents being scanned. Generally, the best way to determine the proper settings for your scanning needs is through trial and error.

Tips for Scanning and Printing at Optimal DPI:

  • Avoid interpolating the DPI.
  • Scan at a lower speed when scanning.
  • Bring your white and black points in a little.
What is V3D Technology?
V3D stands for visual 3D, and is a feature of the SMA Versascan flatbed scanner series. This is a new technology that produces results that look 3D. Different lighting scenarios is the base for the process, where one area of the object is being lit by several different lighting angles, and the scanner captures those different instances. The software within the scanner then combines the separate images into one master image. As a result, paintings and other artwork that are scanned using the V3D technology offers almost perfect reproduction of nearly any surface. To learn more about this technology, please visit our page on versascan products on our website by clicking here.
Can my large format scanner be moved for different lighting conditions?

A remarkable and important feature of the SMA Versa Scan flatbed scanner is that it can be easily moved around. It is built with a unique rolling mount that makes it easily transported to any part of a room or building.

What types of scanners would work best for libraries?
When choosing a scanner for your library that will be used by the general public, students, and library staff, you need a scanner that will give you the most benefits for the lowest cost. So should you get an overhead book scanner or a regular flatbed scanner? Ideally, your library could purchase both types of scanners. A less expensive flatbed scanner would do for most libraries that are only scanning simple documents, and the more expensive overhead book scanner would be good for scanning most types of books.

If you can only afford one scanner though, you will need to consider the different types of documents your library will be scanning the most of. If your library will be mostly scanning books with fragile spines, the book scanners are the way to go. Yet be aware that keeping the book open at 180 degrees can cause a lot of wear and tear on the spine. Also, you must consider the user-friendly features of each scanner. Generally, most people are more familiar with flatbed scanners, which makes them more popular among the general public. Plus, flatbed scanners typically scan at a faster rate than most overhead book scanners. Yet with a little demonstration, anyone can learn to operate an overhead book scanner. Ultimately, the type of scanner you purchase comes down to who will be using the scanner and what types of documents you need scanned.

What types of scanners would work best for state and local agencies?
State and local agencies bid or make contractual agreements to meet all statutory requirements for competitive pricing on either eventual purchasing, their best value to provide professional digital services, or to manage their documents. In this fashion they can establish the most cost effective solution to meet their needs.
What types of scanners would work best for museums and historical societies?
Museums & historical societies look foremost for clarity in a scanner and ease of use. Since more than one person operates the equipment it should have a user friendly format. The flatbed type gives both flexibility and ease of use. A computer program interface that is not overly complex is a plus with staff who will train to use the product purchased. A high optical resolution is also required in order to produce high quality results.

Some scanners can scan in an upright position and they work well to duplicate and provide maximum preservation. A really good option to look for is if scanners have an option for adjustable height or can be moved to different a different location.

Large Format Scanner Maintenance and Cleaning

What maintenance is required for the scanners?
Proper maintenance will help prevent any issues or problems with the scanner. If you are experiencing any hardware issues, cleaning the scanner can help resolve those problems. If the issues persist even after maintenance and cleaning, we advise you to call a professional for assistance.
How can I tell if the scanner requires cleaning?
If the scanner is consistently jamming once a day or even several times a day, it would be a good idea to clean it. Also, if the scanner is grabbing multiple sheets of paper at once, or if the scanner is squeaking or making any unusual noises. Lastly, if the scanned pages have visible lines appearing over the scanned images, that could be a sign that your scanner needs to be cleaned.
What happens to the scanner if I forget or refrain from cleaning it?
Most notably, the scanner will under-perform if it is not properly cleaned on a regular schedule. Refer to the question above for ways to tell if your scanner requires cleaning.
What if I clean my scanner regularly, but it still has issues and problems?
At this point, it would be best to call and talk to a professional about the issues you are experiencing. Contact us today to see how we can help!
Do I need to calibrate my Bookeye scanner?
If properly set up, your scanner should not need much calibration. Yet if you notice a degradation in the quality of your scans, a calibration may be necessary.
How do I calibrate a Bookeye scanner?
The Bookeye scanner allows its operators to perform most calibrations directly from the touchscreen. Within the Scan2Net application, access the setup menu by quickly tapping the time and date field 10 times or more in 10 seconds or less. Now the set up menu should be displayed.

Within the setup menu, you will see a few different tabs and options. The first option should be ‘white balance’. Follow the instructions to complete the white balance calibration. The white balance calibration is most likely the only calibration that you will need to perform from time to time.

Follow the instructions on the screen to undergo the white balance calibration. The calibration process takes around 30 to 40 seconds, so be patient with the machine. After the calibration is finished, the results will be displayed on the screen. If you see any red text, we suggest attempting the calibration a second time. You can also try deleting the white balance data in order to remove any old calibration data that is not relevant anymore. This can be done by pressing the ‘remove white balance data’ button.

If you still continue to see any errors or issues, call your local tech support. Make sure you give them as much information as possible about the issue, and include any screenshots of the display for reference.

For more information on calibrating your Bookeye Scanner, click here to view a calibration tutorial video.

Digital Preservation and Archiving

What Is Digital Preservation?
Digital preservation for archiving involves creating a plan that will outline the method to preserve the original documents, converting them to a digital format, and developing strategy for ensuring the digital archives are properly stored and maintained.
Do the documents contain personal or confidential information?
There are storage requirements and code of practice which involve rules that will limit access and places restrictions on storing certain types of confidential data. You should review all options that are available.
Do you have recommendations for managing the digital documents over time?
It is recommended that digital archives be saved onto new storage platforms every two to four years as technology and digital access changes over time. Also recommended is that digital archives should be stored in multiple locations on multiple storage devices to ensure that failure in one does not result in loss of the documents.
Are there guides for storing archives?
There are specific guidelines to the preservation of our digital heritage. Visit www.digitalpreservation.gov for more information.

There should be a sound development of strategy and policies for storage with complete review of options available.

Digital documents should be stored in multiple locations in case of any natural disaster. Storage rooms should be kept clean without chemicals or water and kept secure through proper locks and secure entry system.

Storage conditions should be properly maintained to ensure the safety of the digital archives. Low temperatures and low humidity ensure the best environment for storing documents. High temperatures and high humidity speeds up degradation. Avoid natural light from within the storage area.

How should I list and catalog my archives?
Just as documents have meaning in relationship to other documents and information, the same is true of digital documents. Maintaining proper cataloging and records will help preserve the relationships to other information to maintain the full meaning and impact of the photos and records stored digitally. This will facilitate quick access.
How should I preserve the original items?
Storage options are significant to maintaining original documents. Archival envelopes and boxes that meet the Photographic Activity Test (PAT) and set by the International Standards Organization (ISO) are best for long-term storage of photos. Refer to the PAT for best practices on storage options.
How many backups of my archives should I keep?
Multiple backups of digital archives are recommended. One storage place for daily usage, and another copy stored on-site as a duplicate. There should also be one or more backup storages kept off-site in case of any natural disaster.
How should I organize and name files within the archives?
Utilize a system where each project is stored in its own folder. It’s often useful to create sub-folders within a project to organize the project. Sub-folders can be used to store date specific archives, or archives by person or family.

Within separate historical time periods, create different folders for different mediums, including photographs, documents, and audio files, under the main folder.

How can I protect my old, fragile, torn documents and books during the scanning process?
Carrier sheets are a great way to protect your documents when using a large format rollfed scanner. White-backed sheets are best for most applications and to reduce light reflection. Black-backed sheets are for specialized applications, including template scanning and tracing patterns for the apparel and upholstery markets, as well as semi-transparent originals printed on both sides (such as newspapers and double-sided maps) – to prevent backside image appearing in the frontside scan.

Benefits of carrier sheets:

  • Protect fragile, dry, aging and valuable materials.
  • Protect scanner glass from documents contaminated with storage debris and dust.
  • Scan documents in badly torn condition or with missing edges.
  • Scan lightweight or oddly shaped originals, including upholstery patterns.
  • Scan transparencies more effectively and minimize light reflection.

Depending on the condition of the documents being scanned, each carrier sheet can last for hundreds to thousands of scans before it should be replaced. To extend the life of your carrier sheets, you can apply a product called Rain-X – with a new formula designed to be used with plastic. Normally this is done to protect glass from wear and tear, but it also works great for scratched carrier sheets.

Please visit our Carrier Sheet page to place an order.

Scanner Rental Information

Which scanners are available for rental, and how does the rental program work?
Large Document Solutions is one of the few companies in the United States that rent large format scanners. To be successful renting scanners, we rent the best scanners available on the market. The characteristics of these scanners include: the most functional software, ease of use, ease of setup, and most important very durable. We rent 42” Contact Image Sensor (CIS) color and monochrome scanners because these are the most flexible scanners for the rental market. Our rental price includes shipping round trip.

Every scanner is thoroughly checked out before it goes out on a rental:

  • The document hold-down unit and image sensors are checked and adjusted, then tested and re-tested.
  • The paper sensors are tested to make sure the scanner is in excellent working order.
  • The glass is examined and cleaned.

Some of the scanners we rent are out for up to 6 months at a time. During those rental periods, the scanner could scan 35,000 to 50,000 documents of any size, shape, and material. Customers use our scanners to scan mylar and paper, old and new. Mylar is a very abrasive material to scanner glass. Before we send a scanner out for rental, we clean the glass with a fine razor then with our own glass cleaner exclusively used for scanner glass. After all the repair and adjustments are complete, the scanner is calibrated. Calibrating your scanner insures the scanner scans what you see on-screen and what you print are all the same.

For more information, please visit our Rental Page.

Plotters/Large Format Printers

What are the differences between pigment-based ink, dye-based ink, and LED dry toner?
Pigment Inks, Dye Based Inks & Dry Toners:
When shopping for a plotter, the question of which types of ink are appropriate for your application is one that can be confusing, and is often a deciding factor in which machine to purchase. There are a few main factors that should be considered when looking at plotters.

Essentially, there are three main options that we offer in plotters that should be taken into consideration; pigmented inks, dye based inks, and LED based printing technology.

LED Printing:
LED (Light Emitting Diode) technology can be a very effective method of printing for black and white applications. LED printing is similar to laser printing in that light is projected on to an electrostatic drum, thereby allowing toner to be attached to the drum in the areas that have been charged by the light emission. The toner is then transferred from the drum to the paper where it is pressed and heated in order to bond it to the paper. LED printers tend to be very effective for black and white renderings, and tend to have great longevity. There is only one toner to deal with, and no print heads that can clog and need to be replaced.

Dye Based Inks:
Dye inks are just what they sound like, ink that dyes the paper or other medium. The potential advantage of these inks is that the end result gives a smoother surface layer on the medium which will result in a more even light refraction. This in turn can, in theory, deliver more consistent color interpretation. This theory does not, however, take into account the light refraction properties of the surface of the paper or other medium. The potential disadvantage of these inks is the bleeding of one color into another as the wet ink is laid into the paper.

Pigmented Inks:
A simple description of a pigmented ink would be crushing a berry and using the crushed pulp to color a medium. These inks have come a long way since the days of cave paintings. Canon’s current line of pigmented inks have a smaller drop size than that of the competition’s dye based ink. Additionally, the Canon Pigment inks have been chemically formulated to prevent the different inks from mixing, so that there is no bleeding of one ink into another. This allows for precise printing of one color over another. The potential disadvantage of these inks is that the pigment particles, as they dry, leave a slightly rough surface, that affects the light refraction properties of the ink, which can effect color interpretation. However, the roughness of the surface of the ink can be effected in different ways by the surface properties of the printing medium, and in our experience has shown no noticeable adverse effects in regards to color interpretation.

Ink Longevity:
There have been numerous tests performed on the longevity of dye vs. pigmented inks. Most of the data points to pigmented inks as being able to last longer than dye based inks. There are many factors that play into this. Under artificial lighting conditions, the two inks generally perform similarly, but under natural light, tests have shown that pigmented inks do generally hold up better. The tests suggest that the time range that these inks will withstand light depredation is in the range of 80 to 100 years. If you desire greater longevity for your plots, there are spray sealants that can extend the life of your plots.

Do Print Heads clog faster when using pigmented inks?
There is no evidence to suggest that print heads will clog faster when using pigmented inks as opposed to dye based inks. With Inkjet printers, the inks are distributed through print heads that have thousands of tiny holes, or jets in as little as a couple square inch area. With both dye and pigment based inks, the ink is suspended in a liquid medium that evaporates away, leaving the dry ink on the paper. After printing, ink that remains in the jets can dry, and clog the jets. The technology is designed so that when new ink enters the print head, that the dry ink in the jets can be re-dissolved in the suspension medium, thus clearing the jets. The best way to prevent clogged print heads is to print regularly. When a print head is stagnant for too long, the ink in the jets can dry to a point that it can not be entirely re-absorbed into the print medium, thus clogging the print head.