What you Know about Smartphone Camera Feature

If you want your next phone to take good photos it can be a bit tricky figuring out which handsets are actually up to the challenge. We have done a bit of digging to figure out exactly where you should be looking to get a device capable of taking the best snaps.

Megapixels 

A phone's camera's megapixel count is probably the most visible spec statistic as manufacturers have got into the habit of boasting about it more than anything else. The problem here is that the megapixel count isn't really that important when it comes to the camera's capabilities and picture quality.

A camera's megapixel count indicates how many million pixels it can capture, which relates to an images pixel resolution. So, for example, an 8-megapixel camera can capture images with a 3264x2448 pixel resolution, because 3264x2448 = 7990272 pixels and, as is often the case with phone and computer specs, things get rounded up to avoid confusion.

There's a problem with relying entirely on megapixels as a measure of image quality though because, depending on the camera's sensor it's possible to have a fuzzier image with a higher megapixel count.

 If a phone has a relatively small sensor, for example, and a high megapixel count, this can mean it's taking in more pixels than it can cope with and the result is a very ‘noisy' image.

Visual noise is one of the main things photographers like to avoid, but in striving for more megapixels you can actually end up making things worse.

For this reason, 8-megapixels is probably about as high as you should go on a mobile camera, and if you can find a phone with 8-megapixels or lower but with better sensor technology then you're heading in the right direction for better quality pictures.

Sensors

If a megapixel rating is in fact the least important element of a phone's camera then the sensor is the polar opposite. The size of the sensor is actually a key factor in determining picture quality.  The reason for this is that the sensor's size affects what's known as ‘dynamic range', which is the range of tones the sensor can capture, as well as noise control.

A sensor uses light-sensitive pixels to capture light which is then used to create the image - a larger sensor means that larger pixels can be used and these are able to capture more light for a better quality picture. This also helps with capturing decent pictures in low-light conditions.

Back-illumination

Another element of sensor design which is becoming increasingly popular in new smartphones is the use of back-illuminated (BI) sensors, also often known as backside-illumination (BSI).

Conventional sensors are illuminated from the front and are easier to manufacture, but the wiring put in place for these either blocks or reflects some of the light and prevents it from being picked up by the light-sensitive pixels. This itself reduces image quality, but it can often be reduced further if the camera setup is made to compensate for the loss of light as it will end up creating extra noise, particularly in lower light conditions.

As the name implies, BSI sensors illuminate from behind, which solves the problems caused by front-illumination and, generally speaking, delivers a better quality image than conventional sensors. Some figures suggest BSI sensors can capture around 30 per cent more light than front-illuminated models.

Sony introduced the first consumer BSI sensor in 2009 with its Exmor R CMOS featuring a back-illuminated design that utilizes the amount of light received results in reduced noise, smoother action sequences, and higher image quality, especially in low-light conditions. 

The problem with this is that too much amplification can reduce picture quality by adding more noise - so ISO amplification is certainly useful at improving image quality but only up to a point.

Dual Camera

2X optical zoom, meaning they can zoom in and out of objects up to double the distance without loss of image quality. In dual camera phones double sensors are there. Next future is of dual camera phones.

Aperture

Aperture is a hole within a lens, through which light travels into the camera body. 

It is easier to understand the concept if you just think about our eyes. Every camera that we know of today is designed like human eyes. The cornea in our eyes is like the front element of a lens – it gathers all external light, then bends it and passes it to the iris. Depending on the amount of light, the iris can either expand or shrink, controlling the size of the pupil, which is a hole that lets the light pass further into the eye. The pupil is essentially what we refer to as aperture in photography. The amount of light that enters the retina (which works just like the camera sensor), is limited to the size of the pupil – the larger the pupil, the more light enters the retina.

So, the easiest way to remember aperture, is by associating it with your pupil. Large pupil size equals large aperture, while small pupil size equals small aperture.

The iris of the lens that controls the size (diameter) of the aperture is called “diaphragm” in optics. The sole purpose of the diaphragm is to block or stop all light, with the exception of the light that goes through the aperture.

F-numbers

The size of the circle represents the size of the lens aperture – the larger the f-number, the smaller the aperture.

In photography, aperture is expressed in f-numbers (for example f/5.6). These f-numbers that are known as “f-stops” are a way of describing the size of the aperture, or how open or closed the aperture is. A smaller f-stop means a larger aperture, while a larger f-stop means a smaller aperture. Most people find this awkward, since we are used to having larger numbers represent larger values, but not in this case. For example, f/1.4 is larger than f/2.0 and much larger than f/8.0.

Depth of Field

One important thing to remember here, the size of the aperture has a direct impact on the depth of field, which is the area of the image that appears sharp. 

A large f-number such as f/32, (which means a smaller aperture) will bring all foreground and background objects in focus, while a small f-number such as f/1.4 will isolate the foreground from the background by making the foreground objects sharp and the background blurry.  Larger the aperture, the smaller the area in focus (depth of field) will be there.

ISO and Shutter Speed

ISO means sensitivity of your sensors to light. Highest ISO takes less time to capture image but there is noise. It is good to keep ISO less in number.

Shutter speed is how long camera keep lens open to capture image. Longer shutter will capture more light but will be vulnerable to shake and blurred movement. For action shots fast that is low shutter speed is required . For low light and lightning conditions longer shutter speed is required.

UltraPixels

More megapixel camera doesn’t mean better image quality because each pixel is getting less light due division of light among pixels. But HTC ultrapixel offers larger pixel to capture 300% of more light than others for better image quality.

Other Features to Consider

For smartphone cameras there isn't much else that is hugely relevant to image quality, but there are one or two features which are worth considering if you're weighing up a couple of different phones over their camera setups.

Digital Zoom

Why? Well it's because digital zoom is fairly pointless, it's only doing something which you can achieve quite easily with a photo-editing suite.

Unlike Optical zoom on regular cameras which actual alter the focal length and magnification. Digital zoom keeps the same resolution and simply crops down on a focal point in the image. This means you'll see a small section of the image in front of the camera and it will be very fuzzy.

Autofocus

This isn't really much of an issue as most smartphones with cameras have autofocus as standard but it's just as well because without it no matter how much you try to avoid it the majority of your photos would come out blurry.

Stabilisation

Stabilisation features are fairly self-explanatory. Phones can have image or video stabilisation to reduce wobble(unsteady movement) and of course some models have both. 

If you can get stabilisation it's a good idea to use it as capturing pictures and video while waving your phone around can be a difficult thing at the best of times.

Digital Image Stabilization gives you shaky videos. But Optical Image Stabilization with gyroscope gives videos without movements.

Having the phone's gyroscope working to counter this can make quite a difference to photos and video you capture.

White Balance

White balance means remedy of yellow-ish or blue tint.

Usually a phone with this feature will have an automatic adjustment capability but they often also have a series of preconfigured modes you can switch to for different light conditions which can improve the quality of white colors in your photos.

Conclusion

In the end it's very difficult to offer constructive advice on what to look for when choosing a phone with a good camera, because the most relevant specs aren't readily available to you as the buyer.

We hope this will change in time, however, as we mentioned the use of BSI sensors is becoming more widely emphasized in phone spec sheets.

The most important thing to be aware of is that megapixels counts aren't everything and you're far better off looking at exactly what sensor technology is behind the camera hardware.