Camera Flashes: Xenon Flash, LED, Dual LED
The most important requirement when taking a good photo is having sufficient amounts of light to illuminate your scene. In low-light conditions (e.g. when taking a photo in a bar or restaurant), the flash on your camera can be an essential source of illumination. Unfortunately, not all camera flashes are made equal… some flashes are brighter whereas other types of flash produce more natural-looking images. In this article, we compare the different types
of camera flash technology.The Flash on Your Camera: Essential Illumination for Low-Light Scenes
The word ‘photography’ comes from the Greek phrase for ‘drawing with light’. Indeed, light is by far the most important requirement when taking a good photo. Without sufficient amounts of light, even bright colours will turn into darkness and it becomes totally impossible to take a good-quality photo.
In an ideal world, there would always be sufficient illumination to take good-quality photos. When taking a photograph outdoors, illumination isn’t normally a problem. Particularly in a sunlight-illuminated scene, there’s normally enough light to take a good-quality photo. Unfortunately, there are also many other occasions where the illumination is insufficient to take good-quality images. A good example is when you’re taking photos in the evening or night-time. Your images will often come out totally dark and lacking in any detail. Another example is when you’re taking photos in an indoor scene (e.g. in a restaurant or bar). It can sometimes be difficult to When there’s insufficient light to take a good-quality photo, it often becomes necessary to add some light of your own. This is when flash technology gets used on a camera: it provides some artificial illumination for you to be able to take that photo.
The Different Types of Camera Flash Technology
The camera flash is a more complicated technology than many people would think. There are multiple competing technologies behind the flash on your camera and they each have different properties, advantages and disadvantages.
Typically, standalone cameras use a technology known as ‘xenon flash’. It’s super-fast and super-quick making it a great technology for illuminating a scene and for freezing your image at a certain snapshot in time.In contrast, most modern Smartphone’s currently use ‘LED flash’ technology. It’s much less bright and has a much shorter range but it has a number of advantages such as better power efficiency. Some modern high-end Smartphone’s have built on this technology and have recently moved to using ‘dual-LED flash’.In this article, we’ll explore the three camera flash technologies in much more detail. We’ll look at the properties of each technology along with the associated advantages and disadvantages. We’ll also look at which Smartphone’s are using each type of flash.
Xenon Flash: A Brighter & Faster Flash Technology
Traditionally, most standalone cameras have used axenon flashtube for illumination in images. It’s a totally different technology to LED-based flash: it’s much brighter and gives a much faster burst of light.A xenon-based flash essentially consists of a flashtube of gas. In order to produce a flash of light, the xenon gas needs to first be ionised. This requires a pulse of extremely high voltage electric (often several hundred volts) which needs to be stored in a capacitor within the phone. When the capacitor discharges through the ionised gas, it produces a super-fast flash lasting a fraction of a millisecond.
Xenon flash advantages:
A xenon flash is super-bright and illuminates a wide area. A Xenon flash bulb emits up to 300,000 lux of light (up to a thousand times brighter than LED). From the inverse square law, we can see the range of illumination will be about 30 times further. So whilst an LED flash may struggle to illuminate objects beyond a couple of meters away, a Xenon flash will easily be able to illuminate objects throughout an entire room. A xenon flash is super-fast and is able to freeze images. Compared to a LED flash, a Xenon flash is substantially faster. It’s able to deliver its light in only 0.1 milliseconds (that’s 1/10,000th of a second). As the burst of light happens so quickly, it can freeze the image as a snapshot in time. This means it should be less of a problem getting motion blur as when using a LED flash.At present, very few Smartphone’s actually use a xenon-based flash.
Xenon flash disadvantages:
Lots of extra hardware is required to add a xenon flash. It’s much more difficult to implement a xenon flash in your Smartphone. Lots of additional hardware is required in the phone, starting with a large capacitor to store the charge. Historically, a 5mm capacitor has been used for this purpose (it’s difficult to fit this in a Smartphone when the latest devices are only 7mm thick).A xenon flash can sometimes be far too bright. A xenon flash is far too bright when you’re taking photos of something nearby (e.g. when you’re taking a selfie). The intense light from a xenon-based flash can also capture artefacts such as dust.A xenon flash can’t be used continuously. With LEDs, you can keep the flash illuminated continuously. This allows you to use the flash as a torch or as anextra light when recording videos. A xenon flash is only able to give short bursts of light and you’ll typically need to wait at least a second before using it again.
A xenon flash uses much more battery. A xenon flash will drain the battery from your Smartphone much faster. The colour temperature can be too high for indoor photography. Xenon flashes will normally give a colour temperature of around 6,200°K (this is even bluer than sunlight). When taking a photo indoors, a xenon flash illuminated scene can often look unnatural. Smartphone’s with a xenon flash include the Samsung Galaxy S4 Zoom, the Samsung Galaxy K Zoom, the Nokia Lumia 1020 and the legendary Nokia 808 PureView. The xenon flash is normally paired up with an extra LED flash for use when recording videos.
The
Nokia 808 Pureview has a xenon flash on the camera.
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| All about LED flash |
LED Flash: The Standard Technology for Flash on Your Camera phone
In 2015, LED is the most commonly-used technology for flash on a camera phone. You’ll find a LED-powered flash on the xiaomi , Samsung , sony and on many other Smartphone’s. An LED flash uses solid-state technology and works in much the same way as a power-efficient light bulb.
LED flash Advantages:
There are numerous benefits to using a LED flash:It’s relatively low cost and power-efficient. The LED flash used on a camera phone uses much the same tech as in a power-efficient light bulb. Nowadays, a LED lamp is fairly easy to produce. It’s also at the stage where it’s fairly power-efficient (important for the battery life on your Smartphone).An LED flash bulb can be used in continuous operation. Unlike a xenon flash, an LED flash bulb isn’t restricted to only being a flash. As it actually works more like a light bulb, you can use the flash bulb in continuous operation (it doubles up as a torch and can also be used when recording low-light videos).An LED flash bulb is fairly small and doesn’t require any additional components. A LED lamp runs on voltages of around 5V (this is fairly easy for your Smartphone to produce). Because of this, it’s not necessary for your Smartphone to have lots of additional components (perfect as it saves a lot of space in our ultra-thin Smartphone’s).
The disadvantages of a LED flash are:
An LED flash is fairly dim and only illuminates a very small area. Typically, a LED flash bulb will only produce several hundred lux of illumination. Because
of the inverse square law, the illumination will drop off rapidly with distance. Hence, you’ll only be able to illuminate objects which are very close by (normally within a couple of meters).An LED flash is fairly slow. The technology behind LED flash is actually more similar to a power-saving light bulb than to a traditional camera flash. As such, LED flashes are fairly slow (the burst of light will typically last around 100ms). Because of this, fast-moving objects can easily get blurred in an image. The relatively-dim flash also necessitates a fairly long exposure time.
The colour temperature will often be wrong for the environment. A LED flash is normally calibrated to around 5,500°K (approximately the same colour as sunlight). When taking a photo indoors, the colour temperature will often mismatch the environment. This means the subject of your image could appear relatively blue.
Our xiaomi device( like Redmi Note 3G/4G, Mi4i, Mi4) uses a LED
You’re Thoughts.
We learn in this article about LED & xenon Led has different technology used , xenon is faster than LED as brighter to now about dual led id quite different frim led or xenon we disscuss about in my next article part 2 all about dual led flash light
Sources: Google search , wiki
Special thanks to @Marcus_keong @BharatG