Q: What is a
scanner? A: A scanner is a device that analyzes
a flat object or 3D object and turns it into a digital image
file. It uses light reflected off of an object to a CCD
or CIS which converts the signal into a digital bitmap image.
Q: What is PPM? A: PPM is an abbreviation for pages per minute, or how many pages a scanner can process in 60 seconds. Flatbeds typically have the lowest PPM, production scanners the highest, with mid-range sheetfed scanners, predictably, somewhere in between.
Q: What is DPI? A: DPI, or dots per inch, is a measurement of scanner resolution. Most scanners have a resolution of at least 300 x 300 dpi. Higher resolutions are usually software enhanced or interpolated, meaning extra pixels are added between the pixels that are actually scanned to increase the perceived resolution.
Q: What is bit depth? A: Bit depth refers to the number of colors that a scanner can reproduce, in color and in grayscale. Most scanners support at least 24-bit color for photos, images, and color graphics. Some offer a higher dpi, like 36-bit, 42-bit or 48-bit color. For grayscale, most scanners typically support 8-bit or 16-bit.
Q: Are higher bit scanners better? A: There are 24-bit, 30-bit and 36-bit
scanners, which is better? 24-bit scanners produce 24-bit
scans. 24-bit scans will give everything you're looking
for in a scan, but if you brighten the image file, you lose
some of the mid-tones and shadow detail. 30-bit and 36-bit
scanners produce 24-bit scans. Confused yet? The scans produced
by the 30- and 36-bit scanners drop 2 to 4 bits of unneeded
information to make for a better image, preserving the look
of the original.
Q: CCD? CIS? What's the difference? A: CCD is now the standard device used
in today's scanners. It stands for Charge Coupled Device
and it works like this: The device accepts light, converts
it to electrical chargers that are then stored and manipulated
into digital images. CIS on the other hand used to be the
standard, but it has been mostly replaced by CCD. CIS based
scanners are heavier and slower than their CCD brethren.
Q: What kind of scanner do I need? A: The kind of scanner you need depends
on what you'll be using the scanner for. Flatbed scanners
will generally give you all the function you need for home
use and are the most affordable. Sheetfed scanners are good
for small to medium offices that do a moderate amount of
scanning. Production scanners are the most expensive, but
also offer the highest performance and a wealth of features.
They can scan 10-150+ pages per minute and are capable of
handling hefty scanning jobs on a daily basis.
Q: What is a flatbed scanner? A: A flatbed scanner, sometimes called
a desktop or photo scanner, is the most common type of scanner
for home or small office use. They're versatile, generally
inexpensive, and great for lightweight scanning jobs, like
bills and documents or for creating digital photos and records.
Q: What is a sheetfed scanner? A: Sheetfed scanners look like small
printers and operate similarly to flatbeds, except the document
is fed through the device while the scan head is immobile.
Some may require the user to manually feed the documents
one at a time. Others have automatic document feeders. Some
sheetfed scanners also offer flatbed scanning for added
Q: Can I scan more than just documents and
photos? A: Yes, a number of scanners also have
the capability to scan film, slides, negatives, transparencies,
business cards, and other items. Make sure you check the
detailed specifications and features to see what kinds of
media a scanner can accommodate.
Q: What is optical resolution? A: Optical
resolution refers to the number of pixels or dots per inch
(dpi or ppi). A greater number of pixels results in sharper
image quality. Resolution is typically quoted vertically
and horizontally. (300 x 300, 2400 x 1200, etc.) If
you want to scan detailed images accurately, accept no less
than a 1200 x 1200 optical resolution rating.
Q: What is interpolated resolution? A: Interpolated resolution is determined
by the scanner adding pixels in between existing pixels
using a mathematical formula to accurately improve resolution
based on the existing pixels. This isn't always the best
indicator of image quality, better to rely on the stated
Q: What is optical density? A: This is a measure of how well the
scanner can capture the tonal range of an image. Optical
Density is measured on a 0-4 scale, with the number representing
the the difference between the darkest and brightest optical
densities a scanner can capture. Most scanners carry an
optical density measure of 2.7-3.1, this is fine unless
you plan on scanning slides, transparencies or negatives,
which will require an optical density of at lease 3.2.
Q: Does my choice of software matter? A: The simple answer....YES. Your scanner
is only as good as the drivers and software that run it.
It's important to invest in a scanner that is bundled with
utilities and drivers that are compatible with your system,
as well as software that allows you to manipulate scanned
Q: How does a scanner connect to my computer? A: Most scanners on the market connect
through either a Hi-Speed USB cord or SCSI port. Some models
connect through FireWire or a parallel port, respectively
the fastest and slowest transfer methods.
Q: Can I attach my scanner to a network? A:This isn't very practical for a multitude
of reasons. The main reason is that scanners can only perform
one function at a time anyway. In addition, additional users
would have to walk back and forth to the scanner, annoying
not only them but the user who's PC is actually attached
to the scanner itself. It's a better idea to purchase a
dedicated scanner for each person who will need them frequently.
That being said, HP offers some high end scanners that come
equipped with an integrated network card.
Q: What does a scan imprinter do? A: An imprinter, whether it's
included in your scanner or bought as an accessory, helps
you keep track of scanned documents, which makes it ideal
for offices that scan a large number of important items.
The imprinter provides a unique number or alpha-numeric
code to each document scanned, printing the code on either
the front or back of the document. Imprinters come in pre-scan
or post-scan models.
Q: Do I need a transparent media
adapter? A: If you need to scan film and have
no other options for getting your images to digital formats,
then it's a good idea to spring for the TMA (transparent
media adapter). This will allow you to more quickly digitize
your film, without having to first process the pictures.
The TMA works by using a lamp above the film, projecting
the image onto the scanner, instead of using the main light
located below the glass.
Q: Do I need to buy a scanner from
the same brand as my computer or printer? A: The majority of scanners on the
market are both PC and Mac compatible, so you can select
the one that best suits your needs and budget without worrying
whether it will work with your computer. Scanners also come
with software to help you install and use your model easily.
Q: What if I need to replace the
lamp in my scanner? A: Eventually, you will have to replace
the lamp in your scanner. This can be postponed by making
sure to turn off the lamp anytime you aren't actively using
your scanner. SuperWarehouse offers a complete line of replacement
bulbs for scanners. Simply call one of our Product Specialists
at (800) 814-5410 for assistance.