I'm trying to resize a photo taken with a Canon 5D Mark III for a 36" X 72" canvas at 300ppi through Lightroom 5. I exported the photo at H: 10800 X W: 21600, but the printing company is telling me that the resolution is still too small. Can anyone give me a suggestion?
We already have quite a few answers on this topic, so you should do some reading at least here:
- Is there a general formula for image size vs. print size?
- What is a suitable image resolution for canvas prints?
The short of it is that you should not resize anything on your side. Let the printer do that for you. Send them the largest image you have before you have tried any resizing. It should work just fine for what you are doing(assuming up to 72 inches) if the image was from a 5D MkIII.