Single lens reflex camera

A single-lens reflex (SLR) camera is a camera that uses a semi-automatic moving mirror system which permits the photographer to sometimes see exactly what will be captured by the film or digital imaging system

Digital SLR's Sensor

Three sensor sizes for digital SLR cameras:

Full Frame (sensor size 24*36)

NIKON CANON

D3X EOS 1Ds Mark III

EOS1D Mark III

APS-H (sensor size approx. 19*29)

Nikon D3000

APS-C (sensor size approx 15*23)

NIKON CANON Nikon D90 EOS 1000D Nikon D3000 EOS 500D Nikon D60 EOS 50D Nikon D5000 EOS 450D

Compact Digital Camera (sensor size approx 5*7

Even if a smaller sensor has the same number of pixels as a larger sensor ,the larger sensor will have larger pixels, larger pixels are more sensitive resulting in higher image quality.Therefore ,image quality does not depend only on the number of pixels.