We regularly are asked how big can I print a photograph from my camera, the table above shows perfect resolution being at 300 pixels per inch and represented by the green tick, the yellow tick represents resolutions that will work and the red cross shows under resolution for that print size.
The human eye sees anything at greater than 180 pixels per inch as being continuous tone, most people can not see beyond 150 pixels per inch, so as a rule of thumb a 20″ x 30″ print can have a pixel dimension as low as 3000px x 4500px.
The quality of you interpolating software can also have an effect on the quality of an enlarged image, we do recommend Photoshop and when increasing the image size you would use bicubic smoother and if decreasing size use bicubic sharper.
All resizing should be done before placing an order through our software, this will improve you chances of getting a better print and will reduce upload times.
While image resolution does play an important part of printing viewing distance also needs to be considered, an 8″ x 10″ print is viewed at arms length and a 20″ x 30″ print would be best viewed from close to a metre and a 12-metre billboard from 15 metres, so where resolution is important the original pixel dimension could be as low as 6 – 8 megapixels for any size print when viewing distance comes into consideration.