The beautiful image above of lunar crater Bullialdus, located near the western edge of Mare Nubium, was taken by Art Cole with an iPhone 4 through the eyepiece of the 60-inch telescope during an evening observing session on April 19, 2013. In an article in the February 2013 issue of Sky and Telescope magazine, Mr. Cole describes his techniques for taking such photos with modern smartphones. The crater is approximately 60 km in diameter and the view shown above is approximately 580 km across, covering less than 4% of the moon's surface.
The small crater Pytheas, centered in the image below, is about one-third the size of Bullialdus. Pytheas is located in the southern region of Mare Imbrium. The larger crater at the "1 o'clock" position from Pytheas is Lambert.
Both images show subtle details in the expansive lava flows of the two lunar maria surrounding them.