A sensor layout unique to Fujifilm which replaces the usual bayer pattern of red, green and blue photosites with a more ‘random’ arrangement. Fujifilm says this eliminates the need for a low-pass filter to combat moiré (interference) effects, resulting in sharper fine detail.
Cameras with interchangeable lenses do not have sealed interiors and the sensors can pick up spots of dust. These can be removed in software using spot removal tools – you dab on the dust spot and the software uses nearby pixels to cover it up. It’s like cloning but easier, because you can leave the software to ‘heal’ the spot automatically.
This is the physical size of the sensor, which is independent of the number of megapixels it has. Bigger sensors capture more light and produce sharper, clearer images with less noise. In fact sensor size is the single most important factor these days in a camera’s picture quality – megapixels are mostly secondary.
Sensor cleaning can be an automatic process carried out by the camera to shake any dust particles from the sensor, but sometimes manual (user) cleaning is needed. This requires a special sensor brush (‘dry’ cleaning) or a swab and sensor cleaning fluid (‘wet’ cleaning). Manual cleaning needs a degree of skill and confidence.
DSLRs and compact system cameras sometimes collect spots of dust on the sensor. The makers get round this by applying a high-frequency shaking action to the sensor to shake it off. This happens automatically when you switch the camera on or off but you can also start it manually.