In order to use images of your project in different media, they have to meet different requirements.
Websites: How changes look on the screen
Web images should be saved in JPG format (a format that keeps files sizes small). Please do not collect or edit images in Word documents!!! For these purposes there are simple image viewers and editors.
Web images should have a resolution of 72 DPI (dots per inch). This means that a computer screen can display 72 dots of image data in one inch.
Prints: "Pixels" make a difference
Dots can be printed much more densely per square inch than they can be displayed on a screen. 300 DPI is the best ratio. This means that if a digital image on a screen has a width of approximately 20 cm in its original size (that is, 20 cm with 72 DPI), then it will be rescaled fourfold to 4.8 cm in the print layout on the same screen (because 300 DPI means four times more colored dots than 72 DPI on a screen).
Therefore, one needs images with a large pixel density in order to print them. This is the simplest solution: If the images have been taken with a digital camera, they should be sent to the designer in their original state and not as scaled-down versions.
The difference between a screen and a print. What appears large, detailed and trim on the screen has to be printed considerably smaller if it is supposed to have the same quality as on the screen (left: flyer in original print size).
For scans of photos that are supposed to be edited afterwards, it is best to save the files in TIF (which cannot be sent via email due to large size) or JPG format with a resolution of 300 DPI (good to best quality).
As with websites, images for powerpoints should be saved as JPGs. A resolution higher than 72 DPI is not necessary.
Photos with digital cameras
For photo documentation, it is primarily digital cameras that are used. You should take some factors into consideration:
- Do not forget spare batteries and a charging device.
- Do not forget a card reader: Some cameras cannot be automatically detected by computers. USB card readers will save you trouble.
- Be mindful of delays: Sometimes digital cameras show considerable delays when releasing an exposure, especially when a flash is needed.