Tuesday, June 24, 2008

lakky 203

he majority of consumers now own a digital camera versus a film camera. However, even in these instances, many still possess film, negatives, and prints that they would like to store digitally, edit, and/or print. The security of storing images digitally and the flexibility of being able to alter and improve such images via editing are very attractive options for prized photographs taken some time ago.

A scanner is a simple and reliable way of converting images into digital form. The most common devices available to consumers are flatbed and film scanners. Determining which scanner to purchase can be made simple by thinking through just a few of the options.

What type of work will the user be doing?

Flatbed scanners are designed specifically for use with photographic prints, paper documents, and even three dimensional objects although some offer a transparency hood or adapter to use them with slides and negatives. Flatbed scanners are a good all round scanner.

Film scanners on the other hand are designed specifically for scanning transparencies, film, and negatives. These scanners offer better resolution for film and negatives than a flatbed and thus are a better choice if a high volume of this type of work is expected. They allow users to scan each frame separately, adjusting resolution per frame.

For those wanting to copy from books, flatbed scanners with a sheet feed function should be avoided as only loose sheets can be fed through. Sheet feed devices also create the risk of jamming.

For those consumers who want to be able to scan, print, and copy with a single device there are multi-function scanners available. These can certainly save on desk space.

What size images/documents will be scanned?

The bed size on a flatbed scanner can vary from the standard 8.5" x 11.7" and to 12"x 17" and larger. Obviously, a large size bed would allow multiple images to be scanned on a single page or to scan larger documents and images.

How much image quality is needed?

The quality is determined primarily by color depth/bit depth and resolution. Bit depth is the amount of information each pixel can carry. More is better of course, but certainly 36 to 48 bit is plenty for most uses.

Resolution is measured in pixels per inch (or ppi); sometimes referred to as samples per inch (or spi). For those scanning text documents 300dpi may be sufficient, but for quality photo scanning 1200 dpi would be the minimum, while film/negatives would require at least 2400dpi.

Dynamic range, which determines the bright to dark range that the scanner picks up is a factor with film scanners. For such devices, a dynamic range of 3.2 would be considered the minimum for good quality.

Is scan speed important?

The speed at which a single document or image can be scanned may be important for those with high volume work. Just as with a printer it can be reported in pages per minute (ppm) but can vary quite a bit based on the resolution and other parameters. Generally speaking, 10-20 seconds to scan an average 8 x10" image is better than average speed.

Is the scanner compatible with other hardware?

For all but the older computers, a USB 2.0 or Firewire connection is appropriate. Firewire allows for the fastest data transfer. Consumers should always assure that their new scanner will have compatible connections to their existing hardware.

What functions are needed?

Most scanners will allow images to scan to print, scan to file, fax, or e-mail with the push of a button. They should also come with the software necessary to scan, edit and even take text to a word processing file. For those wanting a flatbed scanner that will also scan film or slides, the scanner will also need an adapter of some type. Consumers should think through what they want to do with their scanned images to assure that the functions they need are included.

With the introduction of the digital camera to consumers on a large scale, the advantages of storing, editing, and printing from the digital form were readily recognized. For those with images that are in the form of prints, negatives, or slides, using a scanner is a convenient and simple way to convert these images and get the advantages that are traditionally associated with those produced by a digital versus film camera.


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