I took a look at img_3889. There are a few issues which jump out. 1) with the small camera sensor and small lens, any printed photo from the Mavic's camera is basically going to suck. 2) In the image's metadata, the aperture is wide open at f/2.2. So your depth of field (focal point) is going to be shallow. Meaning, not much will be in perfect focus. The camera's sensor actually helped out with this, as small sensors are crummy at creating bokah (blur) outside of their focal point. 3) The main observatory building is over exposed. See how it's bleached out - showing pure white on the left side, without any details, and really bleached whites throughout? Exposure wise, the image just isn't in good shape. However, the focus point of the roofing tiles on the main building is better in the original, than it is in the print that you took photos of. I can't say if the camera you used to shoot the prints was in focus... If so, you are correct - the prints are out of focus. How large is the printed image of the observatory? Being that the original image is only 72dpi (dots per inch) you don't have a lot of room for blowing these up past the size of a postcard, before focal issues start to creep in.
