The 72dpi Web Sizing Myth
The 72dpi web sizing myth. I can't tell you how many times I still hear size my image to 4X6 at 72 dpi for the web. Let's put this to rest once and for all. I am not going to go into the history of how this all started but I want to clarify an issue I run into every month. First, the use of dpi is not correct. Dpi refers to dots-per-inch and is a printing term that has nothing to do with sizing for the web. We use ppi or pixels-per-inch when sizing for print or the web on a computer.
Secondly, you DO NOT use resolution when sizing for the web in pixel dimension. To demonstrate this I am going to show you three different versions of the same image. One is 800x537 pixels at 72 ppi, one is 800x537 pixels at 200 ppi, and the last is 800x537 pixels at 400 ppi. You will notice they all show up exactly the same. That is because 800x537 pixels are always 800x537 pixels no matter the resolution.
Resolution is only used when sizing an image for printing. Think of resolution as image quality. The higher the resolution the better the printed image quality. A 4X6 at 100 ppi image will only have 100 pixels-per-inch resulting in lower image quality than a 4X6 image at 300 ppi. The 300 ppi image will have 300 pixels per inch. Resulting in a better-printed image. Note, all printers have a max resolution. If a printer can only print at 300 ppi there is no reason to save an image a 400 ppi, because the larger pixels density will not result in a better image.
When designing a webpage you must understand this concept. Your photographer or web designer will need an image in pixels (ex. 800x537 pixels.) Furthermore, all images should have the sRGB color profile embedded in the image for accurate color. Hopefully, this will clarify this misconception.
800X537 pixels at 72ppi
800X537 pixels at 200ppi
800X537 pixels at 400ppi
Obviously, these images above are scaled down from their original size to fit this blog. Feel free to click on the each image to see it full size. Any questions please feel free to leave comments below.