Long gone are the days of visiting the one-hour photo-processing shop, taking a favorite photo print and tucking it into an envelope to mail to friends and relatives.

Today, our photos are digital and we move our imagery through the internet � for posting on social media, submitting to a print publication, sharing with family and friends via email, or uploading to a public photo-sharing site.

And there�s more to digital imagery than meets the eye. Most importantly, there�s resolution. Digital images are composed of thousands of pixels, and the more pixels there are in the image area, the sharper the picture will appear at normal size. If you�re curious, zoom in on any photo and you�ll eventually get to the point where all you see is blocks of color. Those are pixels.

High resolution is more important if an image is to be printed than if it�s to be viewed on a computer screen. Most images on the internet have relatively low pixel counts, because images don�t need to have high resolution to present good quality on your computer screen. Also, smaller, low-resolution files download more easily and take up less digital space. So what you see online is not necessarily what you�ll get when you try to print that same photo.

Resolution requirements vary with what you plan on doing with a photo. If you�re simply uploading to social media, lower-resolution files work. When submitting a picture for publication in your favorite magazine or newspaper, however, high resolution is critical. The higher the resolution, the sharper the image will appear in print.

Figuring out the resolution of your image can be tricky, especially if you�re not at a desktop computer when you�re sending it. Photo-editing software programs like Photoshop can reveal the resolution easily, but you may not have access to these types of programs. How can you determine the resolution of your image before sending it to a publisher? The easiest way is to check the size of the file itself. The more pixels an image contains, the larger the file will be on your computer. You can check the size of a file on a desktop computer by right-clicking on the image and selecting �Properties.�

For print, the ideal file size is between 1.5 and 3 megabytes (mb). At less than 250 kilobytes (kb), it will probably only be suitable for use on a screen.

When transmitting photos through the internet for use in a print publication, sometimes difficulties arise in the method being used to send the files. For example, sending photos through a smartphone is quick, easy and convenient. But, depending on the type of phone you have, there is a point at which you might be asked about the photo�s resolution.

If prompted, always select �original resolution� or �actual size� if there is any chance you will want to print the photo (or submit to your favorite publication). Also, keep in mind that any cropping you do on your phone (or filters you apply) will also slightly reduce resolution of a file, as will using a screen capture or saving the photo from Facebook to your mobile phone.

While we�re on the subject of images, if you take a photo you think other readers of Cooperative Living magazine would enjoy, feel free to submit it to our Say Cheese reader-photo column by emailing your original (highest-resolution) image to [email protected].