I am trying to get a photo printed in canvas, b0 size. The original photo is 5472 x 3648 px, 193x128 cm. What happens is: if I adjust the photo in Photoshop it keeps the image size but if I import it into Lightroom to adjust it there, the photo is being

Question

I have checked all the settings when importing..the maximum size Lightroom will keep it is 30x 40cm... Lightroom is doing it to all the photos I import into the program.
I need to be able to export my image from Lightroom in its original size and stop Lightroom of making it smaller.. Any clue on what should I try?
Thanks!
Carol

Answer 1

Digital files don't have sizes in centimeters or inches, meters or yards. They have only pixels. If LR is not changing the number of pixels, it is not changing the digital image. When the image is printed, the number of pixels packed into every inch has a large effect on the quality of the print. This is the pixels per inch number, or "ppi". For a smooth print paper it is generally accepted that 300 ppi produces optimum quality, but for canvas a lower ppi, as low as 150 even, will do. Unfortunately, your camera puts a tag on the digital file which sets a default ppi of only 72. The reason is very anachronistic and silly and is a hangover from 30 years ago when Apple monitors had a resolution of 72 dpi, a measure long ago abandoned. That tag is misleading because it gives the impression that a very large print can be made from the pixels just as they come from the camera (the smaller the ppi, the larger the print) and some beginners think that is the only size print that can be made. But that not true. It is only a default tag, a suggestion, and it can be disregarded or changed (LR changes it to 240 ppi) and any sized print made. The real, operative, ppi will be the pixel dimensions divided by the print dimensions. Your image with all its pixels (uncropped other than to the 1:1.4 paper ratio) will have an operative 93 ppi on b0 paper which is a bit low. I would suggest using LR's resize function to double it to 7296 pixels on the short side.