File sizes
File sizes
Choosing the right file size for stock photos
Before you download your stock photos, it’s important that you check that the image/s you have chosen will meet the needs of the job in hand. To do this, you will need to take two factors relating to the final output into account:
* the printed resolution or dpi
* the dimensions
The dimensions indicate the size that your image will appear when printed, whilst the resolution indicates how much detail will be included in every inch printed. You always need to consider both the size that the image will be reproduced (shown in inches and millimeters below) and the print resolution (shown as dpi) that will be used.
For book and magazine printing, the print resolution for your stock photos typically needs to be 300dpi and above. Large format prints, such as billboards, are usually printed at lower resolutions of under 150dpi (the image is less detailed because it is viewed from farther away) although it’s worth checking with your print department before you start. If they require a higher resolution, Alamy can help you by applying interpolation or upsizing. However, once you’ve received the stock photo, whilst you can shrink it, it cannot be easily expanded without losing quality.
Here are some standard uses of stock photos, showing dimensions, dpi and file size required:
