The Best Guide For A Scanner

So you have decided to go for a scanner but have no idea how to go about it. Before we give you some suggestions throw this fallacy out that scanners are for big spenders or rocket scientists.

How will you be putting your scanner to use? Once you answer this, selection of a scanner will be easy. You need to take a good look at the technology that enhances your scanners performance. Always make a careful study of the rated specifications, design, performance, components and applications bundled while going for a scanner.

In simple terms, a scanner is a device that captures images from photographic prints, posters, magazines and similar sources for computer editing and display. When translated into numeric language, a scanner is a device that converts light into binary characters (1/0) and changes analogue data into digital information.

So how does a scanner function? With the help of small electronic components called CCD (charge-coupled device) or PMT (photo-multiplier tube) as their eyes, a scanner records the amount of light that is reflected off an item being scanned. This is then reported to the computer. Which means that the image is not captured as a single component, it is divided into grids.

The scanning head with its row of eyes records the light reflected from each location. The picture emerges as one digital form from the computer that takes in all the data. Pixels or picture elements refer to each cell in the grid. The number of pixels and the actual process of scanning decide the output of a scanner.

Formerly everyone did not purchase scanners. However, its ability in sending photos across the net and storing documents electronically made it a saleable idea. To help you decide on your particular kind of scanner here is a categorisation of the common user types and the scanner type they should go for.

If you have pictures undocumented and lying around, a scanner will do the needful. They store images and depending on the softwares attached, they could also edit pictures for you. Moreover you save on a digital camera too. Flatbeds, Sheetfed, Photo and Film scanners are just made for you.

Do you have no idea where to store the pile of documents with you ? Then flatbed, sheetfed or a hand held scanner is just the answer.

The flatbed, photo and film scanners would be useful for those who store slides and negatives. Make sure the scanner you buy has a transparency option which is needed for such scanning.

For all of you on the move, smaller versions such as sheetfed, a Photo, a Business card and a hand held are available.

Types of Scanners

Flatbed Scanners

This scanner similar to the copy machines, is the most common available. With a flatbed you may scan documents and photographs. In case it has a transparency attachment it will scan slides and negatives. Price varies within flatbed scanners. The low cost ones cannot match the optical density of the expensive ones. A user-friendly model with an external start button and an USB or a parallel port hook-up is preferable for day to day use. Flatbeds cannot however scan odd-sized documents.

Sheetfed

A sheetfed scanner is a compact unit that gives ample possibility to scan odd-sized documents such as newspaper clippings and legal-sized paper. Resolution of 300 dpi allow for plain text documents. Resolution a 600 dpi is recommended for photos.

Photo

If you scan photos, you may go for this. They are however costly and can scan just standard sized photos, even 5" by 7 " is not accepted by a photo scanner. Slides and negatives can also be scanned.A good substitute for a digital camera.

Film

High-end photo scanning can be done although the scanning is limited to negatives. They have resolutions as high as 2400dpi. Frankly, a flatbed with a transparency option should be preferred.

Business Card

Its use though little is great for those who need to get rid of their mess of business cards. Once scanned into your desktop or PDF you may access the information from there.

Hand held scanner

This ideal device for business travellers can scan quick bytes of information. The more costly models, with their software functions, can straighten and stitch together scanned blocks and fix scanned documents line by line. However they can scan only a few lines at a time.

What to look for in a scanner?

Specifications rarely throw light on any other aspect other than the quality of the output. Softwares, drivers, installation and system requirements are the ones to watch out for when buying a scanner.

The overall appearance may vary from product to product. What is more important are the following attributes.

If a scanner has a resolution of 600 by 1200 DPI, the first number has to be kept in mind. Such a scanner has 600 sensors across its scanning head. A scanner can pick up more details with more sensors. A resolution of 300 DPI is required for text and 600 DPI for graphics. Software algorithms are used for interpolation resolution like 9600 by 9600 DPI which compromises on the quality of the output. Bear in mind that what can be achieved by an interpolation resolution can also be achieved by an image editing software.

An image is studied and recorded pixel by pixel and then translated to a digital form. The amount of information that can be recorded (which is the bit-depth) differs from scanner to scanner. While a 24-bit unit may capture 16 million colours, a 36-bit unit may offer billions of colours. Always keep this in mind: most graphic software confine themselves to 24 bit scans.

Dynamic Range

A dynamic range is the wide range of tones a scanner can record. The count begins with 0.0 (perfect white) to 4.0 (perfect black. Extreme values cannot be guaged by most flatbeds. A flatbed scanner may also miss the subtle difference between dark and light colours at the either end of the range. They usually have a dynamic range of 2.4. Dynamic range is usually cited to make the product more appealing, which in any way does not vouch for better scanning results.

Scanning Area

Always ensure the size of the image this device can scan. For example sheetfed scanners can document up to 8.5" wide and 14" long. Those in businesses like real estate prefer the flexibility of different sized papers.

Scanner speed

The speed of a scanner gains attention relative to its usage. If you scan once or twice a day then a slow unit would suffice. If you are using it too often, the speed of the scanner speaks volumes on your work efficiency. However, there are no concrete ways to guage the speed of scanning operations.

The number game can be deceptive. The claimed raw speed expressed in milliseconds per line or ms/In may rarely match actual performance. The driver softwares, size of its memory cache and the type of connection with the computer are all decisive factors on the speed of the scanner.

To test its speed, scan over a timeframe repeatedly. Other than the specifications the following should be considered.

Bundled software

The effective functioning of your scanner is enhanced by the software provided with it. As a general practice, these softwares are included: driver software, colour calibration software and application software.

Most manufacturers to control the interaction between programs rely on TWAIN. This standard format is followed by most compatible driver software. However some manufacturers who rely on TWAIN do not support a full range of specified capabilities that result in hampering capabilities of their software bundle.

Image editors that come in scanners, help you manipulate your image files. Adobe Photoshop and Corel Draw are examples of image editors.

While installing a scanner some problems may crop up. For an experienced user configuring systems software, setting up drivers and installing add-in cards could be easy. If you happen to be a novice ensure that your system meets all requirements before venturing for a scanner. A Petium processor or a Macintosh with a 68030 processor, with at least 32 MB or more RAM installed is needed for most scanners today.

These guidelines will go a long way while looking for a scanner.