What is the diameter of my lens?
87632
How do I find the thread diameter of my lens?
38712
Diffraction by a lens
55381
What is an ultra-wide lens?
38553
How can I add Lens Flares/Halos?
98410
How to shop for a lens filter?
51290
Does my crop sensor camera actually turn my lenses into a longer focal length?
19213
What do all those cryptic number and letter codes in a lens name mean?
128590
Is the formula for object image size given focal length, etc. independent of sensor size?
88406
What does different focal length offer me?
137585
Canon 75-300mm f4-5.6 USM or 55-250mm f4-5.6 IS lens?
34583
How can I calculate sensor size (width and height) from focus length, vertical, and horizontal angle of view?
40309
Glass acting as a lens?
20086
Why is the amount of light a lens lets in called the 'lens speed'?
1032
What is the reference point that the focal length of a lens is calculated from?
33012
Where can I find the maximum lens weight for my camera?
104610
What focal length lens do I need for photographing the moon?
146325
How is zoom measured?