Services: Scanning
Scanning is the process of electronically converting images from one medium into a digital form for other purposes such as printing, the web or wallpaper for your computer.
The term used when determining the quality of a scan is DPI (dots per inch).
Digital images are made of little tiny squares called pixels. Imagine overlaying a piece of graph paper onto an image, then coloring each square with the color that is most prevalent within that square. If your graph paper has big squares, your image will look like lego blocks. If you graph paper has small squares the image will look much more refined. DPI is the number of squares in one inch of space.
Monitors and TVs can display up to 96 DPI. Anything greater does not increase the clarity of the image so lower DPI images are typically used for web images, slide shows and computer wallpaper screens.
The DPI of an image is more important if you intend to reprint the scanned image.
Ideally, an image should have a resolution of 300 DPI to get an excellent print hovever, to get what we call a good print, you need a resolution of at least 150 DPI.
For example, lets say we scan a 4x6 print at 300 DPI. A new 4x6 print would be excellent when printed at 300DPI. If, however, you wanted it to be enlarged to 8x12 (twice as large) the DPI would fall to half 150 DPI
because you are stretching the same number of pixels to fill the new size.
A formula to determine what resolution your scan would be is:
Desired Width / Source Width * 300
So, if we wanted an 8x12 from a 4x6 it would be 12 / 6 * 300 = 600 DPI
If you wanted to make a 16x24 from then same 4x6 it would be 24 / 6 * 300 = 1200 DPI
Most items can be scanned but 3D items are often photographed digitally instead in order to get a good sharp focus of all levels of the object.
Large items, such as paintings or rugs are always photographed digitally because of the size.
The most commonly scanned items are prints and small paintings, 35mm color negatives, old black and white negatives and 35mm slides but as stated above, we can scan most items.