If I had a dollar for each time I have said this… I could take my wife and kids on a great vacation. What this really means is there is a huge disconnect between what people see on their computers and what they see in a brochure or magazine as far as quality. With more an more people becoming amateur photographers, I run into this all the time.

For starters, I am going to define a few technical terms that are used in the industry to help explain this.

PPI: Pixels Per Inch. This is the number of pixels per inch of an image. Basically the same as DPI. However, when dealing with digital media, almost all applications use this at the standard. The higher your PPI the more detail per inch an image contains

DPI: Dots Per Inch. This is the amount of dots per inch. This generally applies to printed images.

Image Resolution: Wikipedia defines this as “Image resolution is an umbrella term that describes the detail an image holds. The term applies to raster digital images, film images, and other types of images. Higher resolution means more image detail.”

Print: The standard in print is 300DPI or 300PPI

Web: The standard for web is 72PPI or 72DPI

Now that I got that out of the way, let me explain how to apply this. Web images generally have less detail. For instance, a web image that is 5” X 7” at 72 PPI has a total of 181,440 pixels. Wow, that seems like a lot.

The same 5 X 7” image at 300 PPI has a total of 3,150,000 of pixels to make up that image. That is about 15 times as much detail.

This is where it gets a little dicey. Images which are hi-res images can always size down and will appear great for the web. However, images that are fine for the web cannot be resized up for print. What happens is the image never has the detail, therefore, the larger images will what “the industry calls”, pixelate.

Here is a 5 x 7 image at 72 PPI

This image appears to be of good quality. But remember we are looking at this on the web and should work well on the web at this size (Notice the 100% at the top of the image). If we were to use this same photo for printed collateral, this photo would be nowhere near the quality it needs to be and the end result would be disappointing.

Let’s take a closer look at our 72 PPI image. The detail of the photo looked good at 100% on the web. This is what it would look if we were to use the same 72 DPI image for print. Tiny boxes (pixels) appear and the photo looks somewhat blurry.

Let me clear this up. Here is a close up of the same photo that is 5X7 but the original was set at 300PPI. Look at the striking detail in this photo.

Rule of thumb
When preparing an image that you are going to use for marketing purposes. Always keep your original digital file as large as possible. For instance when taking an image with a digital camera. The larger your mega-pixels are set, the more detail you will capture. Lets look at the chart to see what mega pixel camera settings will produce an image that can be used in print.

The first column is your megapixel camera setting. The second is the pixel x pixel count for the image. The third column shows you the print resolution setting and the last column shows you the printed image size it can reproduce.

For instance, the maximum size of an 5-megapixel camera can reproduce is 6.5” x 8.5”

I hope that this clears things up for you.