In what unit is a lens's focal length usually given?
AnswerMillimetres
Focal length is given in millimetres, like 50 mm; longer focal lengths give narrower, more magnified views.
Arts · Facts & stats
Camera facts & stats
7 fact-checked facts about cameras and photography, each with the reason behind it. 5 more are in today's round and join this page after it closes.
The basics
One megapixel equals about how many pixels?
AnswerOne million
'Mega' means million, so a 12-megapixel sensor has about 12 million pixels.
Going deeper
What usually happens when you raise a digital camera's ISO setting?
AnswerImages get brighter but show more noise
Higher ISO amplifies the sensor signal, helping in low light but adding visible grain or noise.
The daguerreotype, an early photographic process announced in 1839, was named after whom?
AnswerLouis Daguerre
Louis Daguerre developed the process of fixing images on silver-coated copper plates.
How does the image formed by a simple pinhole camera appear?
AnswerUpside down
Light rays cross as they pass through the pinhole, so the projected image is inverted.
Expert level
What are the dimensions of a full-frame camera sensor?
Answer36 x 24 mm
Full-frame sensors match the 36 by 24 mm frame of classic 35 mm film.
Changing the aperture from f/2.8 to f/4 lets in about how much light?
AnswerHalf as much
f/2.8 to f/4 is one full stop; each full stop halves the light reaching the sensor.
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