What is a Sensor?
Digital photography replaced the film with a small electronic component, which is called the Image sensor. Sensor is the picture capturing electronic component inside a camera. So the quality of a picture directly depends on the Sensor quality. Yes Sensor size matters !!
The sensor is made of CCD or CMOS , which are semiconductor building blocks of a sensor. There is complex engineering behind these tiny little devices inside the camera which convert the light falling on them into electronic signals which are further processed by the camera hardware to generate pixel values of an image. The process is too much engineering stuff and the camera firmware manages it well ! So lets go further and look into things that image sensor directly influences the photographer.
Full Frame vs Crop Frame.
DSLR and Mirrorless are broadly classified by their sensor size into FullFrame (FF) and Crop frame (APS-C) with respect to a 35mm film standard format. The 35 mm format, or simply 35 mm, is the common name for the 36×24 mm film format or image sensor format used in photography. The FullFrame cameras have a senor size of 36X24mm , while the crop frame (APS-C) have a smaller size sensor. Depending on the manufacturer there is slight variation in the sensor sizes , but we can broadly classify them as shown in the image below:
Full Frame Advantages
- Higher dynamic range and better low light/high ISO performance resulting in higher quality image than a crop sensor.If you shoot in natural and available light full frame sensor will capture more light !
- Shooting with full-frame you get the benefit of a shallower depth of field , which is advantage is portraits and closeup shots.
- Full frame gives better picture details in landscapes and architecture Photography which generally uses wider focal lengths. Also full frame cameras have more wider focal length lenses available than crop sensors cameras. The full frame camera can capture the actual perspective of 35 mm lens format giving better ultra wide frames when compared to crop frames.
Crop Sensor Advantages
- Cost and Weight : While a crop sensor DSLR doesn’t provide the same level of image quality as a full frame DSLR, it does offer major advantages when it comes to cost and weight. Crop frame cameras are lighter and less costly when compared to full frame counterparts.
- Focal length multiplier factor: The amount of difference in focal length with a crop sensor is measured by its “Multiplier.” For example, an APS-C crop sensor having 1.5x multiplier. When a 50mm f/1.4 lens is attached to that APS-C DSLR, the focal length is multiplied by 1.5x and effectively acts like a 75mm lens. This is advantage in Wildlife, Nature , Macro which will have an advantage of higher effective focal length. Below are some examples of crop factor multiplier
| APS-C Brand | Crop factor | Focal length | Effective focal length |
| Canon | 1.6 | 50 mm | 1.6X50 = 80mm |
| Nikon | 1.5 | 50 mm | 1.5X50 = 75mm |
| Sony | 1.5 | 50 mm | 1.5X50 = 75mm |
Focal length measurements on lenses are based on 35mm format field of view. If you are using a crop sensor camera, the sensor is basically cropping out the edges of the frame, which increases the focal length.
- Higher end crop frames cameras have a faster burst mode ( number of shots per second) than full frame cameras. This is because of the smaller sensor size in the crop frames the image processing and buffering can be faster when compared to full frames having similar capacity. However higher end full frames have much better technologies so as to overcome this. The canon 1DX series of cameras have a smaller sensor size (APS-H) for this reason, and is much faster than its competitor.