PIXELS & RESOLUTION
A digital image is a rectangle made up of many small squares of color called pixels. The number of pixels across the width and height of the image is called the resolution. An image with 640 pixels across the width and 480 pixels high has a resolution of 640x480. The more pixels in the image file, the higher the resolution.
DIGITAL CAMERA FILES
Many cameras offer a choice of resolutions from 640x480 up to 5000x3500 or higher. The larger the file resolution, the fewer images that will fit on your camera memory card, but the larger the image can be printed with good quality results. Commonly the size of a pocket digital camera image is proportionate to a 4x5.3 print (a 3:4 ratio), a larger SLR 35mm camera image is proportionate to a 4x6 (a 2:3 ratio), and a typical phone image can be anywhere from 4x6 to 4x8. Phones now take very large resolution files that can make beautiful enlargements. Just be sure to always select the "Original File" size when ordering or emailing.
SCANNING FILM OR PRINTS
The quality of a properly exposed image on film is extemely high and very high resolution images can be obtained with precision film scanning. You can scan the film at any resolution you choose from very low to very high. The higher scan resolutions cost more because they require more expensive scanners and more time during scanning. You should choose your resolution based on your intended use for the files. Remember, as long as you have the original film, it can always be re-scanned at a higher resolution for one frame or the entire roll. See the typical 35mmm and 120 film scanning resolutions available and each resolutions intended use on Page 13 of the Fromex Price and Service Guide here.
Prints can also be scanned at any resolution based on what you are using the file for. If you want to be able to copy the print at the same size as the original, the scan should be at 300 pixels per inch (ppi). See the next paragraph on Resolution Matters When Printing. More informaion can be found on Page 14-15 of the Fromex Price and Service Guide here.
VIEWING IMAGES ON A COMPUTER MONITOR
Images viewed on a computer monitor are displayed at 72 dots per inch or dpi. Each pixel is converted into a dot of color. An image with 640x480 resolution will be displayed on a monitor as 640/72=8.9 inches by 480/72=6.7 inches, or 8.9 x 6.7 inches in size. Therefore an image with 640x480 resolution is a good size image to view on a monitor, email to a friend, use on social media or on a website. Unfortunately, this resolution is too small to make a quality photographic print. Here's why.
RESOLUTION MATTERS WHEN PRINTING
At Fromex, we use the most technically advanced equipment available today to produce beautiful photographs from your digital files. In order to produce a photo quality print, we must print at 300 ppi (pixels per inch); have at least 300 pixels for every inch of the print. In order to produce a photo quality 4"x6" print we need a file resolution of 6"x 300ppi=1800 pixels across the width and 4"x 300ppi=1200 pixels in height. Therefore we prefer a file resolution of about 1800x1200 or higher for optimum 4x6 prints. This resolution would require a 2.1 megapixel digital camera (1800x1200=2.1 million pixels). A quality 8x10 print would need an image file with a resolution of 3000x2400 or higher. Smaller resolution files can be printed, but the results will be less than optimum.
When you order prints online from Fromex using our Xwire software, your images are automatically transmitted to us electronically. You will be able to pick up your prints the next day at Fromex or have them mailed to you..
If you are bringing us a CD or USB drive of your image files, please read our Digital File Setup Guide.
