Scanners: FAQs
How do scanners work?
Reflective scanning
A scanner converts the old (35mm slides) into the new (JPGs)
Conventional scanning involves placing the item, eg a document or book, on the glass plate and closing the lid. The scanner illuminates the item from underneath and uses mirrors to capture the image of the item on the glass plate. This is called reflective scanning.
Transparent scanning
See-through items (slides and negatives) are placed in a special adaptor that locks onto the flatbed; a light will illuminate the items from inside the lid. This is known as transparent scanning (see ‘scan a slide’ for our step-by-step guide).
Only special flatbed scanners have this extra light in the lid so, if you want to scan slides, check that your chosen scanner can do this before you buy.
The scan head will slowly pass underneath the illuminated item, taking the lines of detail as it goes. The image is turned into a digital file using either a CCD (charge coupled device) or CIS (compact image sensor).
Can I upgrade my old scanner rather than buy a new one?
Buying new software is a relatively cheap and effective way to upgrade your old scanner if you don't want to buy a new one. Check out Photo-editing software reviews to find out more.
Is the scanner's speed important?
Speed may not seem like a deciding factor when you're first buying a scanner. But once you've got it home it's easy to lose patience if you're scanning a stack of items only to discover it's taken the better part of a day.
What factors should I consider when purchasing a scanner?
Optical resolution
Quick access buttons are great feature
Bear in mind that a maximum optical resolution of 1,200dpi is adequate for most tasks but 2,400dpi and over will allow you to scan in tiny 35mm slides or negatives and enlarge them.
Useful features
Buttons that allow one-touch scanning are convenient but to access all your scanner's features, you'll need to launch the scanning software and click the 'preview' button before committing to a full scan.
This lets you see a draft version of the scan onscreen so you can select what you'd like to scan and specify the amount of detail you'd like the scanner to pick up.
Advanced settings
Advanced settings allow you to remove dust and scratches, change brightness and contrast or alter the resolution of the image to get a really good scan.