The Ecobee line of smart thermostats can use remote sensors to monitor the temperature in other areas of your house, rather than just where the thermostat is. Unfortunately, there’s no easy and simple way to select which sensor to use at any given time. Here’s a way around that, though, which lets you pick which sensor to use and when to use it.
It used to be the case that if you bought a compact camera you’d have a small sensor, and if you went for an interchangeable-lens camera like a DSLR you got a much larger one. This would also typically be reflected in the quality of the images from those cameras, with larger sensors typically producing higher-quality results than smaller ones.To some extent this is still the case. Sensors are typically the most expensive part of a camera to manufacture, and the larger you go the pricier the camera gets. For this reason you won't find expensive models toting 1/2.3-inch sensors, just as you wouldn't find cheap, basic compact cameras with full-frame ones.Sensors are typically the most expensive part of a camera to manufacture, and the larger you go the pricier the camera gets.However, as manufacturers started offering compact cameras with relatively large sensors, and interchangeable-lens cameras with smaller ones, the situation become more complex. Today, we find some small sensors work very well in a range of conditions, while some larger ones may present a handful of benefits over smaller ones in one way, but fall down in another.Sensor technology has advanced rapidly over the past few years, and the breadth of options across all kinds of cameras is likely to confuse many users, particularly first-time buyers who may not be sure what to expect from different kinds of sensors.
Furthermore, as the size of sensor has a bearing on the effective focal length of your lens, this becomes yet another thing to consider when choosing a new camera.Here, we list the different types of sensor sizes used in cameras today, in ascending order of size, and how each affects image quality. But before we do that, we need to briefly talk about the relationship between sensor size and focal length. Sensor size and focal lengthThe size of the sensor inside a camera has a direct effect on what kind of lenses can be used with that camera.If you buy a compact camera the lens is built into the body, so there's less to think about here from a buying perspective. But with interchangeable-lens cameras like DSLRs and mirrorless cameras, any lens used needs to be able to have an image circle – the diameter of the light that exits the lens – that can sufficiently cover the dimensions of the sensor.Whether they're built into the body of a camera or supplied separately, lenses are marked with their actual focal length, rather than the effective focal length when used on a particular camera. The problem here is that different lenses marked with two completely different focal lengths may provide the same effective focal range to work with when used on the bodies for which they are designed.
To make things easier to understand, manufacturers often provide an ‘equivalent’ focal length, which uses the full-frame sensor as its reference point. A 18-55mm lens used on a camera with an APS-C sensor has an effective focal range of 27-82mm, although the exact length depends on the camera used. Image Credit: Nikon/TechRadar.Here’s an example. A camera with a sensor that’s smaller than full-frame may be used with a lens that has a focal length of 18-55mm, but in reality the effective focal range you’ll end up with is closer to 27-82mm.
This is because the sensor is not large enough to take advantage of the lens to the same extent as a full-frame sensor can. By discarding some of the peripheral areas of the lens, it ends up appearing as though you’re using a longer focal length.Similarly, a compact camera may have a 19mm lens built into it, but if the size of sensor is smaller than full-frame, it will only ever be able to offer a longer effective focal length on that body, perhaps 28mm or so. This figure is determined by the ‘crop factor’ – that is, the number by which you need to multiply the focal length to work out the effective focal length of the combination. This will be examined in greater detail for some of the sensor sizes below. Sensor sizesHere, we take a closer look at the main sizes of sensor used in today’s cameras.Note: not all sensors within the same category have exactly the same dimensions. The measurements provided are an example of one such sensor within that format.1/2.3-inch.
Canon PowerShot SX70 HS. Image Credit: Canon/TechRadar.Dimensions: approx. 6.3 x 4.7mmThis is the smallest sensor that's commonly used in cameras today, and is typically found in budget compacts.
They usually offer between 16-24MP.These used to be common across these types of cameras, but the gradual shift in focus by manufacturers towards enthusiast cameras with larger sensors means they aren't as common in new cameras.Their size allows manufacturers to make very compact cameras with long lenses, such as superzoom compacts like the. They're also found inside DSLR-style superzoom compacts such as the. Using a larger sensor in such cameras would necessitate a larger, heavier and more expensive lens.For general snapshots taken in good lighting conditions, cameras using these sensors may deliver perfectly acceptable results, but otherwise they can struggle to hold on to highlight detail and may produce images with a grainy, noisy texture. Image Credit: Ricoh/TechRadar.Dimensions: approx. 7.6 x 5.7mmSlightly larger than the 1/2.3-inch types above, these sensors make it a little easier to separate a subject from its background, and typically offer better performance with regards to holding onto detail in shadow and highlights. As they can capture more light than smaller sensor, they're also likely to perform better in low light.These were once the default choice for enthusiast compact cameras, but their popularity has waned in the face of larger and more advanced 1-inch sensors (discussed below). Some of the most recent cameras to use these include the Pentax QS1, which was announced five years ago. Image Credit: Sony/TechRadar.Dimensions: approx.
13.2mm x 8.8mmThis type of sensor is currently a popular choice across a range of compact cameras, with its size making it a versatile but high-performing option.It’s most commonly used in pocket-friendly enthusiast compact cameras. Lenses on these cameras will typically be limited to around 24-70mm or 24-100mm (in 35mm equivalent terms), such as on the,. It has, however, also now featured in a handful of superzoom cameras from both companies too, like the Panasonic and, as well as the.Cameras that use these sensors can typically provide very good quality images, particularly as many of the compact cameras that use them have wide maximum apertures that let in plenty of light. This enhanced image quality is partly the result of their size, but also on the technology on which they're based. Recent versions may be built with an unconventional construction, for example, which enables them to capture light more effectively than standard sensors.
When you are troubleshooting your vehicle speed sensor, there are several things that you need to look at. This could end up affecting your transmission, speedometer, ABS, power steering, and your cruise control. A vehicle speed sensor works a lot like a wheel speed sensor.As soon as you start to notice any problems with the aforementioned areas of your vehicle, you need to start troubleshooting immediately, so that you can fix the problem before it gets worse.
Allowing it to go undiagnosed and unfixed will end up costing you a lot more in the long run. Testing the speed sensor is simple enough, and can be done without a professional or any expensive equipment. Testing ReluctanceIf you are dealing with a sensor that is a variable reluctance type, then there will be a permanent magnet that is wire wrapped. It has a magnetic field that partly collapses, thanks to a toothed ring. When your magnetic field collapses, there will be a voltage induced into the wire that is wrapped around said magnet.You can test this with an ohmmeter.
If there is an infinite reading, then this is a sign that there is no electricity going through. If using an analog ohmmeter, then it will show this by staying on the same side as when there are no probes touching. If you use a digital ohmmeter, then there will be no value shown. Test Bad SensorThere are two tests that you can do that will help identify a sensor that is bad. Use an OHM meter to test the integrity of the circuit of the sensor.
This is to check for an open winding. Your sensor should be able to read some type of resistance. The other test is with a scan tool. Install the scan tool, and set it for a data stream.The vehicle will need to be driven, as you monitor the signal of the sensor. Take note of the code that shows up on the scan tool and look up what this code means.
Test MAG ResistiveIf you happen to have a later model vehicle, then your car will probably use the controller area network protocol. This particular sensor gives you a digital signal that will be on the actual on-board computer in your vehicle. Test this with the help of a resistive magneto sensor.With this sensor, an electromagnetic field is powered by the computer. The built-in resistive bridge circuit processes the signal that is given to it, in the form of a digital square wave. The digital signal is then sent to your computer. This is how the speed is calculated. Your scan tool will be the easiest way to test this.
Manually TestIf you want to test it manually, you need to unplug the sensor. Leave the key turned on, with the engine still off. Test for any power, as well as ground from the computer. Plug in the sensor and start your vehicle. Test your signal return wire for a lab scope signal. Make sure that the drive wheels are suspended, at the same time the transmission is put into gear.Vehicle speed sensor accuracy is vital. These tips for troubleshooting will help you regain that accuracy.