How do aperture and focal length affect the DOF or exposure on different sized sensors? | Tyson Robichaud Photo-blography
f-number - Wikipedia
What is Focal Length? (And Why it Matters in Photography)
Focal Length of a Lens
F/# & N.A - Wavelength Opto-Electronic
How Aperture Works | HowStuffWorks
What Is Focal Length in Photography?
What is Focal Length in Photography? - Focal Length Explained
The value of the focal length of the lens is equal to the value of the image distance when rays are (A) Passing through optical center(B) Parallel to the principal axis.(C) Passing
Focal Length of a Lens
Focal Length Explained: A Beginner's Guide – Camera Harmony
F-number, explained by RP Photonics Encyclopedia; light throughput, focal length, depth of field, working f-number