The best 10 scanners in comparison

Scanners are a staple in nearly every office environment – whether it be at home or in the corporate world. And, much like any other electronic device, there is a wide range to choose from – offering a variety of features designed to fit nearly every budget.

The choice comes down to the type of documents you want to scan. Will you merely be scanning black and white documents? Or, will you be scanning documents in color and high-resolution photographs? Do you have a large volume of papers and need a sheetfed scanner? Or a compact flatbed scanner? And, which scanner offers the best bang for your buck? Canon vs. Epson? Well, to help you make an informed choice, we've put together some of the essential specifications and features you should take into account when buying a scanner.

Types of scanners

There are different types of scanners, some designed for home use, others for office use, some even meant to be used on the go.

Flatbed scanners

Most of us have used a flatbed scanner before. Perhaps it was in the office copy room, or at your local library. These types of scanners are particularly useful for scanning things that aren't well-suited for a sheetfed scanner. Some of the things that come to mind are pages of books or magazines, photographs, or fragile documents you don't wish to risk damaging by sending them through a sheetfed scanner. On our category page, you can search specifically for flatbed scanners.

Sheetfed scanners

While many of us have used flatbed scanners to scan a single sheet of paper, it's often a welcome relief to discover the sheetfed scanner, or Auto Document Feeder (ADF), when you have multiple pages to scan. Much like how a copier works, you simply slide the stack you wish to scan into the sheet feeder, and your documents are scanned quickly and easily.

There are two types of sheetfed scanners: simplex scanners, suitable for one-sided scanning, and duplex scanners, which can scan both sides of a paper. However, simplex scanners can do the job of a duplex scanner. You just need to insert the stack into the feeder to scan the first side, and, once completed, flip the stack to scan the other side. The scanner will interfile the pages correctly. This manual duplex feature is enough for the occasional duplex scanning job. Still, if you regularly scan two-sided documents and have to deal with high-volume scanning, you should consider a duplex scanner. These advanced sheetfed scanners are equipped with dual-scan elements, enabling them to scan two sides of the document at once, a real timesaver if you find yourself doing a lot of duplex scanning.

Photo scanners

Generally, flatbed scanners do a decent job scanning photographs for everyday use. Once you scan the photographs, you can use photo editing software to correct flaws and achieve the effect you desire.

However, professional photographers and advanced photo enthusiasts may find they desire some of the features that a photo scanner offers. Features include high resolutions, the ability to scan both positive and negative film, color calibration, and dust and scratch removal.

Portable scanners

Portable scanners are the fare of business travelers and individuals who are on the move and must transfer documents, receipts, and other paperwork into their computer or cloud-based storage while remaining mobile. These little scanners have come a long way from the handheld scanners of yore. They've been downsized for lightweight portability and beefed up to provide excellent scanning capabilities.

Specifications and features

When you're in the market for a scanner, it pays to do your homework. As we all know, it can get a little daunting when you're standing in front of a display of shiny, new scanners trying to decide which one will best meet your needs. So, let's look under the hood of a scanner and see what makes it tick.

Scan resolution

First, of course, is resolution. Resolution is generally associated with the quality of an image. There are two different types of scan resolutions - optical resolution and interpolated resolution.

Optical resolution is the actual resolution that the scanner is capable of capturing, and is the number you should find most important. If the scanner doesn't capture it, then that aspect of the image cannot be improved digitally.

Flatbed scanners usually come with a minimum of 300 x 300 dots per inch (DPI). The optical resolution is determined by the number of sensors on the CCD imaging array: the x-direction sampling rate, and the precision of the stepper motor or the y-direction sampling rate. However, the number consumers will see written on the scanner packaging might be something like 9,600 x 1,200 DPI. That number is a result of the interpolated resolution.

Interpolated resolution is, essentially, a digitally enhanced resolution achieved through post-production. Interpolated resolution can improve, to some degree, the image the scanner has captured. It creates extra pixels between what the CCD sensor scanned.

Bit depth

Among the specifications listed for a scanner, you will find something called bit depth. Essentially, it determines the scanner's ability to read and replicate the color spectrum of the information you scan.

Most scanners have a bit depth of at least 24 bits. That's 8 bits for each of the primary three color channels: Red, Green, and Blue (RGB). Each color channel offers 256 shades of its corresponding color, enabling the scanner to use a range of 16.8 million colors.

Scanners are also available in 30 bits. This results in a total color range of 1 billion colors – 1,024 shades within each color channel. Some of the best scanners offer 36 bits, which ends up being 68.7 billion colors – 4,096 shades within the three color channels.

Keep the bit depth in mind when considering a scanner and what its ultimate purpose will be. Scanners with a high bit depth will read and reproduce the best quality of detail, depth, and color.

Dynamic range

Dynamic range, measured in exposure value (EV) differences, is similar to bit depth, except that rather than the RGB color range, it signifies the scanner's ability to read tones from the whitest white (0.0 EV) to the blackest black at 4.0 EV. On low-end scanners, the dynamic range is generally 2.4 EV, which is suitable for applications where crisp color is not necessary. High-end scanners offer a dynamic range between 2.8 and 3.2 EVs and are ideal for demanding color jobs.

Scanning speed

If you're planning on doing a significant amount of scanning in a day, your first step will be to make sure the scanner can keep up with you. Among the wealth of information on the specification sheet, you'll see specs for page per minute (PPM) for black and white scanning, as well as for color scanning, both determined by the resolution you've chosen. When scanning at higher resolutions, the scanning speed decreases, as the scanner needs more time to capture all the fine details.

If that number looks suitable, the next step is to analyze the scanner's daily duty cycle. This is the maximum number of pages that the scanner can process each day. As a rule, the higher the daily duty cycle, the faster the scanner and the more expensive the scanner is. Another aspect to take into account when choosing a scanner is the feeder capacity. You don't want to keep being interrupted by having to jump up and feed the scanner.

Optical Character Recognition (OCR)

In a world that is working hard to become paperless, Optical Character Recognition (OCR) is one of the crucial features to look for in a scanner. OCR allows the scanner to convert images of text into actual editable text. This feature allows you to scan your paper documents and modify them easily in a document editor. It can also save you hours of retyping when you've accidentally deleted the digital copy but still have the hard copy.