1. Expanding of Field-of-view for small F-number millimeter wave focal plane imaging is analyzed in this paper.

2. When shooting, use a high F-number, this will help to blur the background and focus on the water.

3. The matric characteristics and convergences on F-number space are investigated.

4. The aperture size (area of the aperture) of a lens could be calculated from focal length and the correspondent f-number.

5. The elements in our software include normal photographic parameters like f-number, shutter speed, ISO etc.

6. A simple structured optical testing method-reflecting null correction on a large F-number metal mirror under deep cryogenic environment is presented in the paper.

7. All of the Function keys double as office or operational shortcuts, with the keys themselves sporting the relevant icon while the F-number is printed above them in small but legible fonts.