Product photography image resolution
10 September 2015 | Admin
The subject of image resolution can cause confusion at times because the terminology ‘High Resolution’ and ‘Low Resolution’ are sometimes used to mean different things, such as, a large or small file, how many pixel per inch (ppi), how many dots per inch (dpi), the physical or usable image size or even if the product photography image is destined for use on the web or if its going to be printed.
If you zoom into your picture far enough using an image editor such as Photoshop, the picture will break into individual coloured squares. Each of these squares is one pixel. The resolution of the image is based on how many of these single pixels fit into one square inch when viewed at the pictures full size (100%). This is known as the ‘Pixels per inch’ (ppi).
As a guide, product photography and packshots images with a resolution of 300ppi (pixels per inch) are commonly used for commercial offset printing and have 300 pixels in every printed square inch.
Product photography and packshots images with a resolution of 72ppi are commonly used for websites and have 72 pixels in every square inch of the monitor screen. When viewed at 100%.
Most image editors such as Photoshop will match and display your image at 1:1 with your monitor's screen pixel resolution when the picture is viewed at full size (100%). Therefore, because monitors normally display around 72-96ppi, and a normal commercial offset printed image is 300ppi the image on a monitor will be displayed at approximately 3 to 4 times larger than the images actual 300ppi printable size.
As a rule of thumb you will find that most product photography and packshot images produced professionally will have their resolution set at 300 pixel per inch (300ppi), which is the normal resolution for standard offset printing. These images will need to be resized smaller for web use. The best way of doing this is to establish the required final web image size in pixels rather than mm or inches and use those pixel dimensions to resize your product photography image.
Tip: While viewing an image on a monitor or working in photoshop or most other image editors, try to use image zooms of 25%, 50% or 100%, rather than 33% 67% or other odd percentages. Otherwise the image will likely appear less detailed and sharp when view on your monitor. You may also see ragged edges and monitor patterns known as moiré patterns when viewed at a percentage other than 100%.