Since you included the exposure info, I just have to ask/comment: ISO 800 and 1/4000th sec for a static subject seems like an odd exposure choice. Manual mode for some other subject and you forgot to change settings for this pic? Or were you using an auto mode and the camera made some odd choices? Or perhaps you were driving by in a car and wanted to freeze any motion? Just odd to me since by using ISO 800 you may have lost some sharpness/contrast/dynamic range by effectively underexposing the image (as opposed to ISO 400 and 1/2000th sec, ISO 200 and 1/1000th sec, or ISO 100 and 1/500th sec). Depending on the camera, higher ISO values have a tendency to introduce banding in skies (since you can get gaps in the tonal range with higher ISO values--again varies by camera).