What the best scanner has
- High resolution. Resolution is measured in
pixels per inch/dots per inch (dpi). Experts say that the scanner's claimed
optical resolution is the number that matters – mechanical and interpolated
resolutions are less important.
- Large scanbed size/scan read area. The
larger the scanning area, the larger the document or photo you can reproduce
(and the more smaller images you can scan at a time).
- High color depth. A measurement of how many
variations of colors the scanner can see, this number is generally not
important on document scanners -- but it is very important on photo scanners
and especially when scanning drawings. It's common for high-end scanners to have
48-bit color depth.
- Ability to handle duplex documents. Duplex
scanning is a feature found on more document scanners, which allows both sides
of the page to be scanned at once. These scanners can be expensive, however. If
cost is a concern, consider a scanner with an automatic document feeder (ADF) with
duplexing capabilities; it will only scan one side at a time but it still handles
two-sided scanning automatically.
- Large-capacity document feeder. Again for
document scanning, this feed tray allows you to set up a stack of pages and go.
The best scanners don't jam, stick or pull paper in crooked.
- High number of pages per minute. This figure is
tricky, PCMag.com notes, because higher resolution scans take more time. But
for document scanners in particular, you want those pages to go as quickly as
possible while still producing good results.
- Connectivity speeds of USB 2.0 or higher. The faster the connection to your PC, the faster your documents will
appear once they've been scanned. For quicker speeds, consider a scanner with a
USB 3.0 interface.
- High-end software packages. Software can
add a lot to the value of a scanner. Adobe Photoshop Elements, for example,
which is included on several models in our report, costs an estimated $90 if
bought separately. If you want to
convert scanned text into an editable document, you need optical character
recognition (OCR) software, which is included with many document scanners.
- A good warranty. Standard among all the
better-quality scanners in our report, a one-year warranty should be your
minimum bar for a new scanner.
Know before you go
What will you be scanning? What type of scanner you need largely depends
on what, as well as how often, you'll need to scan. Flatbed scanners are the
most practical for multipurpose use. They're generally more versatile and
cheaper than scanners geared toward a specific function. They're a safe bet if
you'll be scanning delicate material such as photos, film or slides; and
necessary for handling 3D objects or bound material like books and magazines.
Those who need to create digital copies of lots of loose pages and documents
should consider a sheet-fed scanner, which are designed specifically for this
task. High-end photo scanners are relatively expensive, but they're the best
for high-resolution scans of images.
What resolution do you need? If you're scanning plain-text documents or
documents with business graphics, resolution isn't a huge concern – experts say
200 dpi is adequate, and 300 dpi is plenty. New scanners typically have
resolutions of least 600 dpi, which is sufficient for images, as long you don't
enlarge them too much or zoom in too far. For the finest detail or printing
scans at a larger size, you'll need a scanner with a higher resolution – at least
4,800 dpi. Editors at PCMag.com note that you should take claimed resolutions
with a grain of salt, however; these specs are often inflated or are
bottlenecked by the scanner's optical hardware. Though, as a rule of thumb, scanners
with high claimed resolutions typically offer high real-world resolutions.