Depending on the selected aspect ratio, full-resolution photos are either 34MP or 38MP. The camera has a high-resolution 41MP sensor, where the active area is 7712 x 5360 pixels. Depending on the aspect ratio you choose, your camera uses 7712 x 4352 pixels for 16:9 photos and videos, or 7136 x 5360 pixels for 4:3 photos and videos. In order to see the full-resolution photo, you need to view the photo in the Lumia Camera. To open the photo in Lumia Camera full-resolution view, tap the open in Lumia Camera link below the photo in the Photos hub.
Note: This applies to Lumia 1020.