Depth of field and diffraction
What is Focal Length in Photography? - Focal Length Explained
How do aperture and focal length affect the DOF or exposure on different sized sensors? | Tyson Robichaud Photo-blography
Homemade Lenses: Measuring Focal Length, Aperture and F-Stop | Homemade Lens | Flickr
f-stop formula | PBP – Photos By Passy
Numerical aperture - Wikipedia
Lens Calculator - PowerPhotonic
Depth of Field (DoF) calculator | PhotoPills
Absolute and relative lens apertures
Lens Focal Length and F-stop | Digital Camera Know-Hows | Digital Camera | Digital AV | Support | Panasonic Global
Optics technical overview | STEMMER IMAGING
Simple Formulas for the Telescope Owner - Sky & Telescope - Sky & Telescope
F/# & N.A - Wavelength Opto-Electronic
System Throughput, f/#, and Numerical Aperture | Edmund Optics
DahuaWiki
What's a Lens F-Ratio and How is it Determined?
Lesson 23 – DoF Calculator and Hyperfocal Distance - Easy Exposure
Lenses. Field of view and focal length
How Aperture Works | HowStuffWorks
Calculating Projected Image Sizes | Projctn
Aperture in Photography Defined | B&H eXplora
Telescope stats explained | BBC Sky at Night Magazine
