Printing: How Big? Aspect Ratios – Resolution – Size
After having discovered one of your photos looks awesome when shown on your smart-phone screen, consider printing it big and proudly display it on your wall.
Before you commit to printing, mounting, and framing, you best consider just how big can you make the enlargement-print? Four topics should be considered before determining the maximum printing size that can be derived from your JPEG photo file:
Image Resolution*: In digital photography, a “pixel” is the tiniest element identified in an image. The higher the density (pixels per square inch) the better the detail and visa-versa. Image quality on enlargements is best when its diagonal pixel density exceeds 200 pixels per inch. For example: an advertised 8MP (mega-pixel) DSLR camera typically provides an image with pixels arranged horizontally and vertically in a standard 3:2 aspect-ratio, that is, an image pixel layout of 3600h x 2400v. When printed on a 6”x4” common photo print paper, it would have a diagonal pixel density exceeding 600ppi, way better than needed. However when enlarged/cropped and printed onto standard 20”x16” print paper, the density would drop to about 150ppi which may not be best for hanging on the wall. ….So, I suggest for an 8-12MP camera, one should not consider anything bigger** than 14”x11”.
Standard print-paper sizes: There are numerous photo printing, matting, mounting, and framing shops that will provide custom sizes that allow the shape of the print to match exactly that of the original camera sensor. However, normal printing shops mostly use industry-standard photo-paper, mat/mounting, and frame sizes. Anything other than the common/standard sizes can prove to be expensive. If your camera’s sensor shape/aspect-ratio matches your desired print/enlargement size, you are in luck. But, more commonly, standard print paper sizes force most to “crop” or stretch/deform the original image to fit onto standard sized paper. In the USA, the most common print paper and frame sizes are: 6”x 4″, 7”x 5”, 10”x 8”, 14”x 11″, 20″x 16”.
Aspect Ratio: The shape (horizontal and vertical arrangement of the pixels) is determined by the camera’s sensor. When printing onto popular/standard sized media, one must consider if and how any cropping is required. Otherwise, you might be disappointed that the print looks so different then you envisioned. For example, quite a few smart-phones produce images shaped in a 4:5 aspect ratio. This is great for a 8×10 standard print but requires cropping for the 4”x 6 print. Some smart-phones output JPEG images in a 16:9 aspect and most always require cropping pre-processing consideration. Don’t be surprised in the results if you leave this to the printer.
Personal Image-Quality Tolerance: After you have determined your maximum print size, the expected image quality may or may not meet your expectations. If you chose the image to print because it looked fantastic when viewed on the 4” LCD screen of your smart-phone, an enlarged printed image may look fuzzy, noisy, blurry, off-colors, and overall dull. Any imperfection resulting from your camera’s tiny sensor will be exposed when enlarged. These are almost always hidden when displayed on a smart-phones tiny LCD screen. **So, assuming an 8-12MP camera can produce a good 11”x 14” print, if tiny sensors ( smart-phones) are involved, one might better be restricted to 8”x 10”.
* WARNING: Image Files produce/saved by smart-phones, point&shoot camera, even DSLRs should be set at their highest resolution, native size-shape, and at its highest “quality.” The device’s factor default set-up/configuration should be periodically confirmed. Let’s avoid the common occurrence that a user modified these camera parameters and found their camera was taking only thumbnail-sized photos….