Sensitivity and sensor size -governed by the laws of physics.

Sensor technology right now has not really changed for quite a few years. The materials in sensor pixels and photo-sites to convert photons of light into electrons are pretty efficient. Most manufacturers are using the same materials and are using similar tricks such as micro lenses to maximise the sensors performance. As a result low light performance largely comes down to the laws of physics and the size of the pixels on the sensor rather than who makes it. If you have cameras with the same numbers of pixels per sensor chip, but different sized sensors, the larger sensors will almost always be more sensitive and this is not something that’s likely to change in the near future. It hasn’t actually changed for quite a few years now.
Both on the sensor and after the sensor the camera manufacturers use various noise reduction methods to minimise and reduce noise. Noise reduction almost always has a negative affect on the image quality. Picture smear, posterisation, a smoothed plastic like look can all be symptoms of excessive noise reduction. There are probably more differences between the way different manufacturers implement noise reduction than there are differences between sensors.
The less noise there is from the sensor the less aggressive you need to be with the noise reduction and this is where you really start to see differences in camera performance. At low gain levels there may be little difference between a 1/3″ and 1/2″ camera as the NR circuits cope fairly well in both cases. But when you start boosting the sensitivity by adding gain the NR on the small sensor camera has to work much harder than on the larger sensor camera. This results in either more undesirable image artefacts or allowing more noise to be visible on the smaller sensor camera. So when faced with challenging low light situations, bigger will almost always be better when it comes to sensors. In addition dynamic range is linked to noise as picture noise limits how far the camera can see into the shadows, so generally speaking a bigger sensor will have better dynamic range. Overall camera real camera sensitivity has not changed greatly in recent years. Cameras made with one size of sensor made today are not really any more sensitive than similar ones made 5 years ago. Of course the current trend for large sensor cameras has meant that many more cameras now have bigger sensors with bigger pixels and these are more sensitive than smaller sensors, but like for like, there has been little change.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.