If you want to print photos or poster yourself or scan old slides or negatives, there are some things that you should definitely know and observe.
First of all, the terminology is crucial.
What does the term image resolution and abbreviations dpi and ppi?
A digital image is composed of many pixels. The resolution refers to nothing more than a certain number of points or pixels on a given route.
The resolution of an image is given as ppi (pixels per inch = pixels per 2.54cm) or dpi (dots per inch = Points per 2.54cm).
The optimal image resolution depends on what you want to do with the image. The resolution of an image for the screen is not relevant. Do you want to make a poster or photo print, however, the image resolution is critical. Most online vendors Poster require 75 dpi, with 100 dpi are generally considered to be optimal.
For documents (eg Word), it is sufficient completely, if the photos have a resolution of about 200 to 240dpi.
If you want to scan photos and convert them into digital images, you should know this, the most common settings.
Most photos are equal scanned at the highest possible from the device screen resolution. But that only makes sense if you want to enlarge its photo strong. For normal photo prints reaches a resolution of 300 dpi, for poster rich even 125 dpi.
First you need to decide for which output format you need the image. Depending on the size of the target format and the size of the original photo must be scanned with greater or lesser resolution (dpi = dots per inch). For a photo print in the same format as the original, 300dpi is sufficient for scanning. If you want to print the image enlarged or take a picture, you need to adjust the scanning resolution accordingly.
There are also photo prints below the resolution limit of 300dpi printable.