Camera sensor physical size. Does size matter?

     Cameras come in all shapes and sizes..... of sensors, the digital sensor that captures the image as a computer file. Point and Shoot cameras have sensors the size of your pinky fingernail and smaller. Many Single Lens Refllex (SLR) Cameras have an APS-C size sensor that is smaller than the 35mm film frame these sensors have replaced. Then there are" Micro 4/3rds" cameras that have sensors in between. More recently cameras have come out with a "Full Size" sensor, meaning it is the same size as that 35mm film.  Medium format sensors are bigger yet. So whats the deal with these and does it matter what size you get? Here's the basic rundown:

     In general the image quality, low light performance, and ability to attain shallow depth of field increase as the sensor size goes up.

     Point and Shoot size sensors typically have less quality of image and less dynamic range (how many shades between the darkest dark and the lightest light in the photo), and poor low light performance. They have a large depth of field (how much is in focus) due to the science of the lens/sensor size relationship. That's why you can't get a shallow depth of field on a phone camera.

Micro 4/3rds Sensors have improved image performance but still allow cameras to stay smaller in size.

     APS-C Cameras can have yet again better image quality and better low light performance and are common in most consumer targeted SLR's.

     Full Frame Cameras have improved image quality and another step of improved low light performance (Bingo). Also the ability to achieve shallow depth of field is improved per the sensor size. Another "Bingo".

     Medium format sensors have amazing image quality and larger number of Pixels for better large reproduction quality. They have the ability to achieve amazingly shallow depth of field. It's important to note that the low light performance is usually less than full frame sensor cameras. I expect this is because these cameras are intended for studio or more controlled light situations, and they trade low light performance for other performance features.

     The main thing is to know that your point and shoot camera can come away with nice pictures, as long as there is enough light. The more you spend (sensor size) the more performance you get. And improvements are being made every year. Until three years ago, all digital cameras had poor low light performance.