Digital camera sensors come in many sizes these days, ranging from medium format (high-end costly camera) to what is placed into a smartphone. Sensor size and technology directly affect the quality of your images.
To understand sensor size we should start by knowing that today’s digital camera sensors are sized in relation to the 35mm film size of traditional SLR cameras. Know that what we today label a ‘full frame’ sensor is the equivalent of yesteryear’s 35mm film size. If you take two sensors with identical technical specs, it can be generally said that the larger the sensor is, the better the quality your image will be.
Manufacturers place a variety of sensor sizes into today’s digital devices. To label these sizes/formats, each is scaled in relation to the full frame (35mm equivalent). The chart below illustrates some common sensor sizes. The largest sensor shown, the medium format Kodak sensor, resides in a high-end studio camera.
A rule of thumb says that the larger the sensor, the more light it can absorb (but again, remember that the quality of the sensor hugely affects things). That means improved color, sharper detail and low-light images will have more of a fighting chance. On the flip side, small sensors must fit their light-absorbing pixels into a cramped space. When taking a photo, what happens is that heat builds up and creates the digital “noise” (random speckles) that you notice in your photos.
With this comparative chart you can see what cell phone cameras are working with versus a good quality point-and-shoot versus a DSLR. Shopping for a new digital camera? Take a look at this site. It does a decent job of stacking up sensor comparisons for numerous devices: https://www.digicamdb.com/