Making sense of the digital camera sensor sizes

Digital Photography Review has a nice summary of the sensor sizes in digital cameras. The sensor affects the noisiness (how small pixels), the depth of field, the crop factor, and the focal length multiplier. Here is a short listing of typical sensor sizes (diagonal measurements) in compact digital cameras:

• 1/2.5 inch = 10 mm
• 1/2.33 inch = 10.9 mm
• 1/1.8 inch = 14.1 mm
• 1/1.7 inch = 14.9 mm
• 1/1.63 inch = 15.6 mm
• 2/3 inch = 16.9 mm
• 4/3 inch = 33.9 mm

Of these the 4/3 inch sensor is already in the digital SLR area, a quite big sensor. As the area is proportial to the square of the diagonal, the noise characteristics improve dramatically with bigger sensors. On the other hand, depth of field and focal length multiplier decreases, so there are drawbacks (if you think this as drawback).

It seems that soon there will be interesting new cameras on the market. Panasonic Lumix DMC-LX3, annouced yesterday, has a 15.6 mm sensor. And it is speculated that we will soon have also a Nikon P6000 (with a 14.9 mm sensor) and a Canon G10 (14.9 mm). These cameras may generate competition in the more serious compact cameras.

Update: It seems I was a bit mistaken in my thinking, thus I wrote some updated thoughts on the sensor sizes.