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Aug 09
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What is Pixels Per Inch?Art, photography Comments Off
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Many of us confuse Pixels Per Inch with Dots Per Inch or haven’t heard the term PPI. PPI is a measure of the standard of a print and understanding this term and what the number means will help you establish the right sizes and resolutions for your next digital photograph print.
PPI describes the number of pixels per inch in a photograph. PPI is a result of the quantity of pixels the camera’s sensor supports ( AKA megapixels ) and the dimensions of the photo. To work out a photograph’s PPI simply multiply the page length by its width in inches.
The result’s the amount of square inches on the page. Now divide the amount of pixels the sensor supports by the quantity of square inches. The result’s the quantity of pixels per square.
All that’s left to do is to find the square root of this number.
Following is a table that shows the PPI for diverse page sizes for a five megapixel camera.
page size: 4X6 – 456 PPI
page size: 5X7 – 377 PPI
page size: 8X10 – 250 PPI
page size: 11X14 – 180 PPI
page size: 16X20 – 125 PPI
page size: 20X30 – 91 PPI