Image Guideline

What is resolution?

If you are creating images to use for print and the images are “too small” the odds are the resolution wasn’t high enough. The image might look huge on your computer but still print out quite small. To add to the confusion, your screen resolution will also determine how big the picture appears to you when viewing it on your computer.

It’s important to begin with a high-quality image which means the highest resolution and image dimensions you can get. When it comes to source images, bigger is better, because you can go down in size, but not up, without losing quality.

Here are a couple of quick examples to show you the difference, no matter what your monitor resolution, it’s all relative!

The first example below has a lot of detail.

The second example is at 72dpi but scaled up to the same size so you can see the difference in detail. The actual image would be about 1/4 the size when you go from 300dpi to 72dpi, but at the same height and width is where you can actually see the difference.

300dpi Example

300dpi Example

72dpi Example

72dpi Example

DPI: Dot’s per inch. The number of dots in a printed inch. The more dot’s the higher the quality of the print (more sharpness and detail).

PPI: Pixels per inch. Most commonly used to describe the pixel density of a screen (computer monitor, smart phone, etc…) but can also refer to the pixel density of a digital image.

Resolution: Resolution is the measure of pixels in the display, usually expressed in measurements of width x height. For example a monitor that is 1920 x 1080 is 1920 pixels across and 1080 pixels down.

Higher resolution means more detail. Higher DPI means higher resolution. Resolution is not “size”, but it’s often confused with it because higher resolution images are often bigger, but that doesn’t necessarily have to be the case.

Print: 300dpi is standard, sometimes 150 is acceptable but never lower, you may go higher for some situations.

Web/Digital: DPI doesn’t equate to digital it’s a print measure. It was commonly believed for a long that 72dpi was ideal for web. If you hear that it’s simply not the way things work. When talking digital, we’re concerned with the actual resolution. How that image prints is another matter.

Understand Image resolution

In digital photography, camera resolution is associated with a number of different factors:

  • Print Size – usually the most important factor. Basically, the more resolution, the larger the potential print size. Printing from digital images is accomplished by squeezing a certain number of Pixels Per Inch (PPI). A high quality print with good details usually involves printing at around 300 PPI, so the size of the potential print is calculated by taking image width and height and dividing them by the PPI number. For example, a 12.1 MP resolution image from the Nikon D700 has image dimensions of 4,256 x 2,832. If you wanted to create a high quality print with lots of details at 300 PPI, the print size would be limited to approximately 14.2″ x 9.4″ print (4,256 / 300 = 14.2 and 2,832 / 300 = 9.4). Larger prints would be possible, but they would require you to either drop the PPI to a lower number, or use special third party tools that use complex algorithms to upscale or “up-sample” an image to a higher resolution, which do not always yield good results. In short, higher resolution is usually more desirable for the ability to print larger.
  • Cropping Options – the higher the resolution, the more room there is to potentially crop images. Although many photographers avoid heavy cropping, sometimes it is necessary to focus on the desired subject(s). For example, sports and wildlife photographers often resort to cropping, because they might not be able to get closer to action, but at the same time do not want their final images to contain unnecessary clutter surrounding the main subject(s). As a result, they often employ heavy cropping, which ultimately reduces resolution, which is why they tend to desire as much resolution as possible and practical.

Judging from the above, it seems like higher resolution is always better. But that’s certainly not the case, because it is not just about the quantity of pixels, but their quality.

Print quality table

table