Low f/stop = fast lens?
20086
Why is the amount of light a lens lets in called the 'lens speed'?
20168
Wide Angle Lens on a Step Down ring?
129613
Why does illuminance stay the same for a given f-stop even when focal length changes?
133548
How can a speedbooster improve the light performance of a lens?
51707
What low-cost non-fisheye wide angle lenses are available for Canon and how do they compare?
62822
How can lens cause consistent front or back focus?
74906
What causes an f/0 error on a Nikon D700?
22374
What methods can be used to micro-adjust autofocus of a camera body to a particular lens?
84007
Why are there no fast APS-C zooms beyond 55mm?
135149
How do camera body motors compare to in-lens motors for focusing?
143273
Recommended shutter speed for action sports?
77901
Is it worth it to buy an FD-EOS adapter, or is it better to exchange a misbought lens?
106533
Why is a physical anti-aliasing filter still needed on modern DSLRs?
158181
How does the lens diameter influence photo quality?
58265
What happens to a lens when you turn the focus ring during AF mode?
21523
How can aperture be f/11 on a lens with an aperture range designation of 3.5-5.6?
8552
Which focal-length lens is usually used for portrait photography, and why?