IT tutorials
 
Graphics
 

Adobe PhotoShop CS5 : Acquiring Digital Images - Scanners

11/27/2012 5:39:18 PM
- How To Install Windows Server 2012 On VirtualBox
- How To Bypass Torrent Connection Blocking By Your ISP
- How To Install Actual Facebook App On Kindle Fire
Shooting on film is still a valid choice. Film offers greater flexibility for low-light situations, and it offers some aesthetic options not afforded by digital capture. Many purists swear that shooting film adds richness in detail and color, as well as introduces subtle nuances like film grain, which cannot be replicated with a digital camera. Additionally, many pictures that you’ll need to work with might only exist on traditional media (such as prints) or as a negative. You’ll need to use a scanner to turn these optical formats into digital formats.

Note: Other Applications

Digital photographers who have large collections of digital images to manage will often use a library management application. Two of the most popular are Adobe Lightroom and Apple Aperture. Both have excellent integration with Adobe Photoshop.


Choosing a Scanner

If you work in a computer lab or other work environment, your choice in scanners may have already been made for you. However, it is still important to understand the different types of scanners that are available to consumers.

Flatbed scanners

The most common scanner type is a flatbed scanner on which photos are loaded face down on a piece of glass. The scanner then moves a charge-coupled device (CCD) across the image to capture/digitize the image. High-quality scans can greatly increase the amount of data that is captured. So, be sure to look at high-speed scanner-to-computer connection options. For a modern computer, FireWire or USB 2 are the best options.


Be sure to pay close attention to the optical resolution of the scanner: This is the maximum size of the image before using software interpolation to enlarge it. Most users doing intermediate-level work or desktop publishing find a scanner capable of 600 to 1200 spi to be adequate. Remember, samples per inch can translate fairly well into pixels per inch. It is a good idea to have more pixels to start with, and then reduce the size of the image for delivery.

Common ppi Requirements for Final Files

Output MethodTypical ppi
Onscreen (Web/slides)72–96
Laser printing150–250
Newsprint120–170
Offset printing250–300
High-quality offset printing300–600


Film/slide scanners

Specialized scanners load in slides or film negatives. These scanners use a tray to hold the material, and then a motor pulls the tray slowly across an optical sensor. This process is relatively slow due to the resolution needed. The scanner must capture a lot of data from a very small surface area to produce a usable image. These scanners are slightly more expensive than flatbed scanners but are essential if you frequently work with slides or negatives.

Drum scanners

When top image quality is a must, pros turn to drum scanners. These units are very expensive (starting at $5,000 and increase significantly). This is the oldest scanning technology. It calls for the image to be mounted on a drum. The drum is then rotated in front of a photomultiplier tube. The tube is much more sensitive than the CCDs used in flatbed scanners. Drum scanners’ primary advantage is resolution, and they should be used when you need to significantly enlarge a scanned image (such as museum archival pieces or for magazine output). Because the machines are expensive and very complex (as well as potentially destructive), users will often send images to a service bureau for drum scanning.

A drum scanner is a highly specialized piece of equipment. These machines are very expensive and are usually found only in high-end service bureau facilities.

What Size to Scan? Think in Pixels

People often get confused when determining which settings to scan with. Too little information and the picture goes soft. Too much information and the scanner slows to a crawl. The answer is to know your intended output resolution as well as your device.

Tip: Need a Scanner?

Many all-in-one printers combine a printer and scanner, essentially creating a fax machine and photocopier in the process. Be sure to check if your printer offers scanning software to load your traditional photos. You can also rent scanners at many local photocopy shops.


For example, if you need to create a 20-inch-wide poster that will be printed on a high-quality press requiring 300 ppi, use this calculation:

20 (inches) × 300 (ppi) × 1.25 (pad for flexibility) = 7500 pixels

Do not adjust your scanner’s dpi (or ppi) settings. Rather, crop the image after running a preview scan. You can then adjust the scanner’s resolution by looking at the output size of the scanned file. As you adjust the output file size, the scanning software will automatically determine the appropriate settings for samples per inch. All scanners tell you just how many samples you are about to capture. Looking at these numbers gives you a truer sense of the end result. Total pixel count is much more important than dpi, especially when scanning images of various original sizes.

 
Others
 
- Adobe PhotoShop CS5 : Acquiring Digital Images - Digital Cameras
- Web Apps & Design - Responsive Site Design (Part 2)
- Web Apps & Design - Responsive Site Design (Part 1)
- Image Libraries Changed The World For Designers (Part 6)
- Image Libraries Changed The World For Designers (Part 5)
- Image Libraries Changed The World For Designers (Part 4)
- Image Libraries Changed The World For Designers (Part 3)
- Image Libraries Changed The World For Designers (Part 2)
- Image Libraries Changed The World For Designers (Part 1)
- Photoshop Elements 11
 
25 Inspiring Game of Thrones Quotes
 
Top 10
 
- Microsoft Visio 2013 : Adding Structure to Your Diagrams - Finding containers and lists in Visio (part 2) - Wireframes,Legends
- Microsoft Visio 2013 : Adding Structure to Your Diagrams - Finding containers and lists in Visio (part 1) - Swimlanes
- Microsoft Visio 2013 : Adding Structure to Your Diagrams - Formatting and sizing lists
- Microsoft Visio 2013 : Adding Structure to Your Diagrams - Adding shapes to lists
- Microsoft Visio 2013 : Adding Structure to Your Diagrams - Sizing containers
- Microsoft Access 2010 : Control Properties and Why to Use Them (part 3) - The Other Properties of a Control
- Microsoft Access 2010 : Control Properties and Why to Use Them (part 2) - The Data Properties of a Control
- Microsoft Access 2010 : Control Properties and Why to Use Them (part 1) - The Format Properties of a Control
- Microsoft Access 2010 : Form Properties and Why Should You Use Them - Working with the Properties Window
- Microsoft Visio 2013 : Using the Organization Chart Wizard with new data
programming4us programming4us
 
Popular tags
 
Video Tutorail Microsoft Access Microsoft Excel Microsoft OneNote Microsoft PowerPoint Microsoft Project Microsoft Visio Microsoft Word Active Directory Biztalk Exchange Server Microsoft LynC Server Microsoft Dynamic Sharepoint Sql Server Windows Server 2008 Windows Server 2012 Windows 7 Windows 8 Adobe Indesign Adobe Flash Professional Dreamweaver Adobe Illustrator Adobe After Effects Adobe Photoshop Adobe Fireworks Adobe Flash Catalyst Corel Painter X CorelDRAW X5 CorelDraw 10 QuarkXPress 8 windows Phone 7 windows Phone 8 BlackBerry Android Ipad Iphone iOS