This item is written as f/ X, where X is some number, and the item’s true meaning is “focal length divided by X.” Light doesn’t just pass through the one single middle point inside them as was shown in the previous image, and so spec sheets give their aperture value as well, which describes their lens speed. We have a few more things to say here about lenses. What this tells you is that the given lens has the same angle of view as a specific other lens would have on a full-frame sensor.įor example an 8mm lens on a sensor with a crop factor of 3 is equivalent to a 24mm lens on a full-frame sensor (8mm×3=24 mm). This gives you the equivalent focal length. The sensor is marked with a thick line the gray square is the lens.Įven though the angle of view can be calculated from the sensor size and the focal length, it’s simpler to just multiply the focal length by the crop factor. An 8mm lens on a sensor with a crop factor of 3 gives the same angle of view as the 24mm lens on the sensor on the right. Notice how, to get the same angle of view, the lenses need significantly different focal lengths for the different sensor sizes: To achieve the same angle of view on differently sized sensors, a different focal length is needed.
It’s indicated with an f, and it means the distance from the sensor to the lens’s optical center. Nevertheless, for lenses what’s presented as their main parameter is focal length. The picture below illustrates two different systems with two different sensor sizes, with two lenses that have an identical angle of view. Source: Wikimedia Crop Factor Helps You What’s What in Lenses Meanwhile in medium-format and larger cameras, the sensors are larger than full-frame and thus have a crop factor of less than 1 (typically from 0.5 to 0.8). A smartphone sensor thus has a diagonal 6× smaller than for full-frame DSLRs, and a surface area roughly 36× smaller (“roughly” because they can have different ratios of sides). Typical basic DSLRs have a crop factor of 1.5 or 1.6, mirrorless cameras have a 2, and the sensors in smartphones have around a 6. Smaller sensors have a crop factor of greater than 1.
#Aps camera meaning full#
Smartphones: Sensors Up to 36× Smaller Than in Full Framesįull frame sensors have a crop factor of 1 and are the reference for crop factors. The higher the crop factor, the smaller the sensor. And that’s what the crop factor is.Ĭrop factor expresses how many times smaller (or occasionally larger) a given sensor is than a frame of 35mm film measured as a diagonal.
1/4”).īecause it’s hard to compare sensors, and above all the lenses mounted on top of them, when they’re expressed like this, a relative comparison was introduced. Unfortunately for historical reasons this is not the diagonal for the sensor, but rather for the cathode-ray tube (CRT) that would have represented it back in the age of analog video cameras. Because its dimensions matter, a camera’s spec sheet will almost always mention either the sensor’s width and height in millimeters (e.g. Crop Factor Can Tell You Sensor SizeĪny hardware manufacturer can make a sensor of any size-and they do. These sizes, and the properties that result from them, are defined by the crop factor. But they share one origin-the use of sensors and lenses with different sizes. Multiple factors are behind the differences between these devices. The picture from the DSLR, however, has a much blurrier background. The picture above shows the outputs from a full frame Canon 5D Mark IV DSLR and an LG G4, each with a similar angle of view and similar aperture settings (f/2 for the DSLR and f/1.8 for the phone). Comparison of a photo from a smartphone with one from a full frame DSLR, with comparable apertures and angles of view. This is marvelously visible when you compare examples from opposite ends of the spectrum-large full-frame DSLRs vs. Especially as far as depth of field is concerned. You’ve probably noticed that you can get significantly different pictures when using the same exposure (aperture, speed, and ISO) on different cameras. You’ll see them in the focal length, lens speed, and sharpness. Meanwhile the differences can be quite striking. But fewer know how exactly it influences the way that photos from phones, compacts, and APS-C DSLR cameras look compared to photos from a full-frame camera. And many of them are also vaguely aware that it defines a sensor’s size relative to a frame of analog film. Practically every photographer knows the phrase “crop factor” (sometimes also called “focal length multiplier” or “focal length magnification”).
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