How to choose a Scanner

What is a Scanner? | Scanner types | Scanning components | Scanner characteristics | Recommendation tables Tips

 

What is a Scanner?

A computer scanner is a very convenient tool to input graphics and text information to a computer as bitmap or text file. The scanner digitizes reflected light. An internal sensor picks up reflected light and converts it into digital information that your computer can understand. Here's a guide to help you figure out which special features you should seriously consider and which would merely be fun to have. Unlike most computer peripherals, the selection and pricing of scanners is virtually the same whether you own a PC or a Macintosh.

The following key features can help you more to find the right Scanner:

• Scanner types

• Scanning components

• Scanner characteristics

Recommendations  to choose the best scanners

Table 1 -Recommendation to choose by affordable price

 

Price (%)	Resolution (dpi)	Flatbed scanner	Sheet fed scanner	Film scanner
50-100	up to 600	yes	yes
100-200	300-1200	yes	yes
200-300	600-1200	sometimes plus TA and ADF	yes
300-500	600-2400	sometimes plus TA and ADF	yes
500-1000	1200-2400	yes	yes	yes
1000 and up	1600 and up	yes	yes	yes

Table 2 - Recommendation to choose a type of scanner

Feature	Goal
	Scan graphics or photos	Scan negatives, slides, and transparencies	Scan text document for soft copy, fax	Scan text document for editing	Scan 3D originals, such as flowers	Scan by portable/ handheld device	Scan for e-mailing
Seldom or One-time use	Flatbed	Film scanner	Flatbed	Flatbed	LIGHTSHOW 3D Object Scanning System
Multi-page document	Sheetfed, flatbed with ADF	Film scanner	Sheet fed, flatbed with ADF	Sheet fed, flatbed with ADF	N/A	N/A
Low demands to quality of image or text	CIS or CMOS, low resolution	CIS(CMOS) +TA	CIS(CMOS), low resolution	CIS(CMOS), low resolution		CIS (CMOS), low resolution	File in jpeg format
High  demands to quality of image or text	CCD + high resolution	CCD +high resolution	CCD, high resolution	CCD, high resolution	CCD, high resolution	CCD, high resolution
High speed of scanning	SCSI, USB or FireWire)  interface	SCSI, USB or FireWire)  interface	SCSI, USB or FireWire)  interface	SCSI, USB or FireWire)  interface	CSI, USB or FireWire)  interface	USB
Limits speed of scans.	EPP  interface	EPP  interface	EPP  interface	EPP  interface	EPP  interface
Portability						For easy scanning of text in, for example, library

 

Tips for Choosing a New Scanner

• For most applications, a 300dpi scanner is adequate, although most inexpensive scanners offer 600dpi or better. For graphics and photos, if you need to enlarge the images to more than twice their original height and width, you need 600dpi or better. For scanning film, you will generally need resolutions of 1,200dpi or more.

• Ignore interpolated resolution when making a purchase decision. It doesn't tell you about the quality of scanning, only how well the software can fix it up. And if you want to interpolate your images, the best way to do it is generally by using a graphics program after scanning.

• If you want to work on your images with software like Photoshop or Photo Deluxe, start out with a scan at the highest resolution and color depth your system can handle. You can always reduce them to smaller files later.

• Image editing: There are different levels of image editing. Less expensive scanners usually come with simple programs for the casual user. More expensive scanners come with sometimes-overwhelming programs aimed at the professional or serious amateur.

•  Scanning at a higher resolution than you need simply uses up disk space without improving image quality.