What's the real focal length for 18-55mm in my APS-C camera?
15644
What is crop factor and how does it relate to focal length?
76237
What do I need for extreme macro photography?
6598
How to calculate the correct focal length needed for a subject of a given size and distance?
40865
What should I do when I have lenses with different filter thread sizes?
11996
How do I find the right size of filters for a lens?
5740
What is a good wide-angle prime lens for Nikon DX (APS-C) format?
83556
What are the theoretical minimum and maximum apertures?
30788
Is the camera sensor or the lens the limit to resolution?
157805
How do I use the different shutter speeds my camera offers?
72405
Is it better to upgrade Canon 18-55mm IS kit lens to the 18-200mm, or complement with 55-250mm?
52368
Does the diameter of the aperture increase with increases in the focal length with constant F-number(F-stops)?
8552
Which focal-length lens is usually used for portrait photography, and why?
113839
How can I visualize or simulate the effect of different focal lengths?
116433
Camera image in pixel to real image in meters size relation
42808
Simply bad focus or too big aperture?
58821
How can the aperture value written in Exif be larger than the nominal limit of the lens?
129401
How can I find a compact camera with an ultra-wide lens?