Difference between zoom and focal length?
11197
How do I convert lens focal length (mm) to x-times optical zoom?
71343
Is there a noticeable difference between 1.8 and 1.4 prime lenses?
21744
Focal length of an ellipse and related results
104610
What focal length lens do I need for photographing the moon?
14565
How does background blur (bokeh) relate to sensor size?
57844
What lens focal length most closely resembles the perspective of the human eye?
158181
How does the lens diameter influence photo quality?
37632
How to compare the focal length of a 50mm prime lens with the default lens of a point and shoot camera?
146325
How is zoom measured?
117216
Difference between focusin/focusout and focus/blur, with example
10820
What is the formula for percent of frame filled at a specific distance and focal length?
63434
Technically, why is the out of focus area blurred more when using a bigger aperture?
113163
Why do some lenses focus past infinity?
85095
Selecting optical size?
152115
Can I convert binocular zoom to equivalent lens focal length?
109652
What is the limiting factor in lens construction when it comes to f-stop values?
42808
Simply bad focus or too big aperture?