My sensor is bigger than yours! The truth about sensor sizes…
My sensor is bigger than yours! The truth about sensor sizes…
My sensor is bigger than yours! The truth about sensor sizes… By Raphael Chieza
Every digital camera from the dingy generic compact to the heavy duty pro DSLR have a sensor and it’s really this, along with the optics in front of it, that determines what level of image quality (IQ) you are going to get from your camera. However, it still begs the question of how much bigger is one sensor size over another and what about the effects of a high pixel count? Read on and find out the actual difference and how to get the highest IQ possible for your needs.
Sensor Sizes
From the diagram below, you could see the different sizes of sensors that are available in many of the digital cameras in the market. Traditional consumer photography is based around the 35mm film format with sensors considered as “full frame” if the sensor’s size is of the same frame size as the 35mm film. Other smaller sensors are termed cropped sensor due to the “cropping affect” that due to the smaller size sensor. It is important to note that for the smaller size sensors, companies then to use a different notation to denote size instead of the measurements of the sensor itself. When you see a sensor’s size such as 1/1.7-inch, this does not denote diagonal measurement of the sensor area but rather the outer diameter of the long glass envelope of the tube. This is rather misleading as the diameter of the imaging circle is invariably larger than the diagonal of the sensor area, the fact that there is no specific mathematical relationship between the two and the reality where most people would assume it to be the diagonal measurement of the sensor area.
Advantage of Larger Sensor Sizes
Under similar conditions, the larger the sensor, the better the image quality you’ll get from it. It’s a simple matter of physical limitation. More light can be exposed on to a larger sensor and thereby delivering sharper details, better colour and clearer low-light images (as there are more light shining on the sensor in total). Furthermore, a by-product of a larger sensor means you will need larger lenses to sit in front of it. Once again, this means that you are often provided with a choice of better lens combination as well. This is why photographers tend to get cameras with large lenses (not referring to telephoto “large” here) as they are invariably coupled with a larger sensor.
High Resolution and Pixel Density
So large sensors are better are they? Then why does a 14.7 megapixels 1/1.7-inch sensor appear to deliver worse images than a 8 megapixels 1/2.3-inch sensor camera? The reason is simple and that comes to a question of pixel density and camera noise handling. Approximate calculations gives 339k pixels per square mm with the 14.7 megapixels 1/1.7-inch sensor and 124.8k pixels per square mm with the 8 megapixels 1/2.3-inch sensor. This shows that the pixel density is almost 3 times higher on the larger sensor, which makes the pixel size proportionately smaller as well. What this means is that there are more chance for stray light from adjacent pixels to stray in to each pixel and thereby contributing to more “noise” in your image. This is much more apparent as you dial up the ISO sensitivity and view your rather “snowy” image as the noise manifest itself more apparently. Therefore, while larger the sensor the better, it is also important to note that you don’t have an excessively high pixel count. Of course, the noise handling technology of the camera in question would also make a difference to the final result but the previous statement is pretty much accepted. Clear examples where higher resolution is shown as unnecessary includes the Canon G11’s resolution cut from the higher resolution G10, as well as the evident resolution cap imposed on the Nikon D300, D300S, D3 and D3S.
New Age of Compact Cameras?
With the recognition that the use of larger sensors is the most obvious way to improve IQ of compact cameras now that the current limit to pixel density seems to be reached, it would not be surprising to see more 10-12 megapixels cameras in the compact market with larger sensors and finer optics. The introduction of the micro FourThirds system and cameras such as the Sigma DP1 and DP2 are merely the heralds of things to come. Will smaller sized sensors go away? Not likely as the sophistication of technology will no doubt give us smaller and smaller devices that are more portable while maintaining an acceptable level of IQ for the general consumer.
Nowadays, yes... density counts. Noticeable with Canon design of G10 & G11.
But why manufacturers made in different sizes? I don't believe they can't. Marketing?
I believe in invention and discovery. To create a pocket size dslr with resolution like or more than Nikon D3s is posible.
From the diagram below, you could see the different sizes of sensors that are available in many of the digital cameras in the market. Traditional consumer photography is based around the 35mm film format with sensors considered as “full frame” if the sensor’s size is of the same frame size as the 35mm film. Other smaller sensors are termed cropped sensor due to the “cropping affect” that due to the smaller size sensor. It is important to note that for the smaller size sensors, companies then to use a different notation to denote size instead of the measurements of the sensor itself. When you see a sensor’s size such as 1/1.7-inch, this does not denote diagonal measurement of the sensor area but rather the outer diameter of the long glass envelope of the tube. This is rather misleading as the diameter of the imaging circle is invariably larger than the diagonal of the sensor area, the fact that there is no specific mathematical relationship between the two and the reality where most people would assume it to be the diagonal measurement of the sensor area.
Under similar conditions, the larger the sensor, the better the image quality you’ll get from it. It’s a simple matter of physical limitation. More light can be exposed on to a larger sensor and thereby delivering sharper details, better colour and clearer low-light images (as there are more light shining on the sensor in total). Furthermore, a by-product of a larger sensor means you will need larger lenses to sit in front of it. Once again, this means that you are often provided with a choice of better lens combination as well. This is why photographers tend to get cameras with large lenses (not referring to telephoto “large” here) as they are invariably coupled with a larger sensor.
