The advent of digital photography has changed how we take photographs, but what about those boxes and albums filled with all the photographs taken years or even centuries ago? Scanning them and other large-volume collections (e.g., documents, art work, etc.) into digital format is the best way to preserve these visual histories for generations to come. As multifunction printers with scanning capabilities rise in popularity, it may seem that purchasing a dedicated scanner is no longer necessary, but that depends on your scanning needs. If those needs are more than the occasional document or collection of business cards, a dedicated scanner will produce greater quality digital images. Pronto’s Scanner Buying Guide explains the options so that when you go to buy, you already know what you’re looking for (see also Multifunction Printer Buying Guide).
For scanning large volumes of documents, photographs, negatives, slides and even artwork, standalone scanners provide better quality scans than those built into multifunction or all-in-one printers and they won’t break the bank unless you need to invest in an super high-end machine (estimated price range $125-1,000).
Most experts will tell you that unless the physical size of the hardware is driving your decision, you should invest in a flatbed scanner. They can scan a wider variety of objects and generally produce sharper images than sheet-fed scanners.
Optical resolution trumps interpolated resolution. The former is often called the scanner’s “true resolution” because unlike interpolated resolution, it’s not enhanced by software. Look for a minimum of 2400 dpi, even if you think you don’t need it. Be sure the scanner’s resolution doesn’t exceed your other devices’ resolution, especially your printers.
Contact Image Sensors (CIS) scanners are smaller than Charged Couple Device (CCD) scanners, use less power and are more stable. However, CIS don’t produce images quite as sharp as CCD scanners. If you’re a detail-oriented person, stick with CCD scanners. For casual or home use, CIS should be fine.
If you’re scanning documents you will need to edit. Look for optical character recognition (OCR) software that transforms the image into editable text. For photos and other graphical images, look for photo-editing software if you don’t have it already. If you’ll be scanning items that are old and perhaps flawed, some scanners come with built in or add on features that ‘erase’ imperfections.
Scanners “remember” a number of bits from each image pixel. The more bits the scanner remembers, the better the image. A minimum of 24 bit depth is recommended. For high end photography and graphics, go higher.
A method of changing the size, resolution, or colors in an image by calculating the pixels used to represent the new image from the old ones. It is also being used to increase bit-depth claims on scanners (as in "Enhanced Bit Depth" or "Enhanced Color").
Pixels Per Inch (ppi)The number of pixels captured per inch by a scanner. This is a more accurate rate term than dpi (dots per inch) when applied to scanners because scanners capture pixels.
Like printers, scanner resolution is measured in dots per inch (dpi) and sometimes pixels per inch (ppi). The higher the resolution, the better and more detailed the image. Evaluate your options based on this measurement versus interpolated resolution which is manipulated by software.
Optical character recognition. Many scanners come with software that lets you scan a document and turn the text into text that can be edited in a word processing program.
In a word, yes. Especially if you’re looking to convert a large, traditional photograph or document collection to digital format for preservation—with the casual, consumer focus on multifunction models, standalone scanner technology has gotten better, but that doesn’t mean you’re limited to pricey, high-end models. General use scanners, like the Epson Perfection V100 (est. $125), may not be the speediest scanners, but come with resolutions and bit depths high enough to produce quality digital images. These scanners are viable options for the home or casual user. For business users or digital graphics/photography enthusiasts, you may want to consider a more specialized scanner, like the Epson Perfection V750M Pro.
What determines which end of the range of scanners you should purchase from? The overall ease of use of the scanner of course, along with the variety of materials you’ll be scanning and additional features and/or software applications the scanner may or may not come with. If you’ll be scanning slides and film, for example, you’ll need one that comes with a transparency adapter built in or can connect to a separate adapter unit. If you’ll be scanning documents that you’ll later need to edit with a word processor, you’ll want a scanner with optical character recognition (OCR) that converts the image to actual text. One warning: not all scanners are compatible with both PC and Mac platforms, so be sure the one you choose is compatible with your machine.
The majority of scanners are flatbed scanners and if you’re going to be scanning a variety of items, a flatbed is what you want. Flatbed scanners are capable of scanning bulky items that can’t go through a sheet feeder (e.g., books, magazines, artwork or other three-dimensional objects). Flatbed scanners also feature the highest optical resolutions, but lower-priced models may have a maximum image size of standard 8 ½ x 11. If you need to scan documents larger than that, look for flatbeds with dimensions that meet your needs. Sheet-fed scanners can’t accommodate bulky items, so they’re less versatile than their flatbed counterparts, but they’re also smaller and take up less desk space. Some models are small enough to travel with you if need be. If you’re on the fence about which of these is best for you, it comes to image quality: flatbed scanners produce sharper scans because the scanning head moves past the item you’re scanning, hence why these types have the highest optical resolutions available. Experts say that unless size and/or portability are top concerns, buyers should choose a flatbed.
True scanner resolution is optical resolution not interpolated resolution. Interpolated resolution will read higher than optical, because it’s been enhanced by the software bundled with the scanner and that’s why manufacturer claims and advertising focus on it. Always base your decision on the scanner’s optical resolution capabilities. As with printers, the higher the resolution, the sharper the image created. If you’re scanning images for Web use or looking only to print small photographs (4 x 6 and smaller), you can get away with 100-200 dpi. For larger works, purchase the highest optical resolution you can afford, just make sure that, a) your printer’s resolution is as high or higher and, b) you have enough hard disk space to store and print the images (higher resolution scans produce larger-sized files). Look for a minimum of 2400 dpi, even if you think you don’t need it. You can’t add resolution later. For documents only, 600 dpi should be enough.
Resolution, however, has nothing to do with color. Scanners “remember” color from the original when they scan and how much color they “remember” is measured in bit depth. A minimum bit depth of 24 will be enough for most users, but some, like Pronto’s Pick, the HP Scanjet G4050 Photo Scanner, have bit depth as high as 96.
Scanners scan using one of two sensor methods: contact image sensor (CIS) or charge-coupled device (CCD). Scanners with CCD employ bright light that lights up the image and rows of pixels capture the image. CIS scanners create images by capturing the light from beneath the object being scanned. What does this mean to you? CIS technology is newer, smaller (and thus, CIS scanners are smaller) and uses less power than CCD technology, but can’t match the sharpness of CCD scans. Think about what you’ll be scanning and for what use. Home users will do fine with CIS scanners while professionals or sticklers for detail will want to stick with CCD.
All scanners come with the software needed to scan an item and transfer it to your computer, but most people want to do something with those images once they’re created. Some software bundles include features that can erase flaws from the original. If you don’t already have photo-editing software, look for a scanner that includes these kinds of tools. Ditto for documents: if you’re scanning now to edit later, you’ll need optical character recognition (OCR) capabilities that can turn the image into actual text.