There are plenty of misconceptions about the number of pixels, resolution, image size and so on, which can make us quite confused sometimes. To make things worse, the terms DPI (dots per inch) and PPI (pixels per inch) are often used interchangeably, which makes the understanding even more difficult.
Essentially, DPI is important for printers. It’s a number of color dots printer uses to reproduce colors of the image. It’s also used for screen resolution, although PPI can also refer to screens as well. PPI applies to everything in relation to resolution and the size of a digital image.
In this video, you will see a brief explanation about DPI and how important is this value for printing big formats. How big is big enough? Does size matter at all?
In the video, Thomas Kuoh explains the importance of the number of DPI for printing large formats. First of all, we mainly see our photos in digital format nowadays and we rarely get to print them. But when there are prints to be made, even a 42 MP sensor will give us 16.5” x 17.7” photo when printed at 300dpi. So, how do we print big formats then?
The logic is pretty much as follows: the larger the size, the smaller the DPI. This is because with larger formats, you will need to step back to see the entire image. Thus, the billboards are printed at only 15dpi. Imagine observing a billboard. If you want to see the whole of it, you need to stand far from it. So, you are not likely to see the huge dots of paint from a distance and the resolution will not seem off.
Glossy magazines are printed at 150dpi. As Thomas points out, you rarely open the magazine and think that the resolution is bad and you can see the dots. The same goes for computer screens, which have from 72 to 100dpi. Although, Apple’s retina displays have 300dpi. Finally, fine art prints should be printed at 240dpi.
There are plenty of different tips, information and advice for printing, both large and small formats. Most of them don’t really accord with each other. What do you think? How do you print your images?