Kirk Mastin, on printing an photo taken with an iPhone at 12x18:
Of course if you view the image closer than 2–3 ft you can see the grain in the image. However, most photos of this size are usually viewed at a distance of at least 4–6ft away. In this case, the photo looks amazing. The grain in an iPhone photo is irregular. iPhone photos have much smoother grain than many digital point and shoot cameras, which is a great thing: iPhone photo grain mimics analog film grain.