If you just need a simple, everyday document scanner, then picking the right one is pretty easy. But if you want to have more options and need to scan photographs or even film negatives, then making the right choice can be more complicated. Consider both document and flatbed scanners, along with other specialty types, to ensure you have a model which works for all of your needs. When it comes to image quality, you want to look at the color depth, the element or image sensor, and optical resolution to ensure you get as good a scan as possible. Below are some additional things you should consider before making a purchase.
Different Types of Scanners
While there are quite a few different types of scanners out there, the two most common ones are document and flatbed scanners.
Document scanners
Document scanners have a feed or tray where you place a sheet or small stack of paper which is then pulled into the machine to scan each page. Some of these models have to be loaded manually with one piece of paper at a time, while others can handle multiple pages at a time. Document scanners are usually the best choice if you just plan on scanning in sheets with text and similarly-sized pages.
Flatbed scanners
A flatbed scanner has a flat piece of glass onto which you place a sheet of paper or object to scan it. Flatbed scanners often provide better image quality and are preferable for working with mediums such as photographs and illustrations.
Special Types of Scanners
There are also several specialty scanners to consider if you have some different or unusual objects to scan. Some devices are marketed as dedicated photo scanners, usually with a small bed for traditional photographs or film negatives. If you're looking for a scanner that has print, copier, and fax capabilities as well, then check out the best all-in-one printers for some great options.
Slide scanner
One specialized type of scanner that is very useful is a slide scanner, which scans images from photographic slides. Most flatbed scanners cannot capture these kinds of images very well, so a special model is a wise investment if you have many slides you want to scan and save digitally.
Pen scanner
Pen scanners are great for portability and individual lines of text. This is especially helpful if you need to scan from a large, bound book that can’t work with a document scanner and would be unwieldy with a flatbed model. These are especially helpful for notetaking as you can save notes almost instantly instead of rewriting passages by hand.
Different Types of Element Types/Image Sensors
The term “element” is typically used when looking at document scanners, while flatbed scanners often use the term “image sensor,” but in both cases, it refers to the technology used to pick up light and create the scanned image.
Charged coupled device (CCD)
A CCD image sensor offers the best picture quality and detail, so choose a flatbed scanner with CCD if you want the best-scanned image possible.
Contact image sensor (CIS)
CIS is not quite as good as CCD, but still provides good quality and is lightweight. Choose CIS for a document scanner or if you don’t need the level of performance offered by CCD.
Complementary metal-oxide semiconductor (CMOS)
CMOS is the lowest in terms of quality, but also more affordable. This type is a decent choice purely for document scanning where you don’t need high resolution or image quality.
Features to Look for in the Best Scanner
Maximum optical resolution
The resolution of an image describes its width and height of it in terms of pixels. More pixels mean better image quality, so choose the highest resolution available for what you need. Optical resolution refers to the scanning resolution, so the higher the value the better the captured resolution.
For document scanners, look for about 600x600 or 600 dpi. This isn’t exceptional but is more than sufficient for text and low-quality images. If you want a flatbed scanner for photographs or illustrations, then you want a much higher resolution. Choose a flatbed model with a resolution of at least 2400x2400 or 2400dpi, though 4800x4800 or 4800dpi is a much better choice. If you need incredibly high resolution for professional photography or illustration, you can even go up to 6400x6400 or 6400dpi.
Maximum document size
The maximum document size compatible with a scanner depends a lot on how the device is designed. Document scanners have a slot that can only fit paper of certain sizes, while flatbed scanners have a piece of glass that limits the size of the object or page that it can scan. The maximum size you need depends a lot on what you will be scanning, but there are a few things to keep in mind.
Most document scanners can handle pages 8.5 inches wide, with varying lengths, and legal pages up to 8.5 x 14 inches are usually compatible. If you need to scan 11x17 inch ledger pages, then look for a model with a wider paper feed. Flatbed scanners are likely to be large enough to handle up to 8.5- x 14-inch pages, but you will probably need to pay more if you need a large model that can handle ledger pages due to it requiring more glass and a wider bed.
Color depth
Color depth, also called bit depth, refers to the amount of data, in bits, used for each pixel in a scanned image. More bits mean more data is used, which means you get better image quality. So, choose a model with as much color depth as possible for pictures.
If you’re just looking to scan text documents and similar items, then a color depth of 24-bit should be sufficient. For photographs, you want to choose a scanner with at least 48-bit color depth for great image quality. There are some scanners available with 96-bit color depth, but that is pretty unnecessary.
Additional USB ports
Just about every scanner on the market connects to your computer through a USB port, though there are some wireless models available. If your available USB ports are getting a bit limited, then consider a scanner that has USB input ports as well. This lets you connect other devices to your scanner, which then connect through it to your computer. You can pretty easily find document scanners with at least one available USB port, but they are less common in flatbed models.
Manufacturer and warranty
Since scanners are electronic devices with a lot of moving parts and sensitive components, it is important to choose a model made by a reliable manufacturer that covers the device with a good warranty. Companies like Epson, Canon, HP, and Fujitsu all make excellent scanners that work well and provide you with very good scanned images. You can also look at Brother, Kodak, and Xerox for good, reliable machines. A one-year warranty is pretty standard for scanners, but you may be able to find some models, especially professional ones, with longer protection.