This is all about basic camera elements of the smartphone and focusing technique.A basic idea of smartphone camera with some features like Dual Tone Flash. Suggestion please post on: unosikandar@gmail.com

1. Smartphone
Camera

2. Elements of a SmartPhone Camera
Lenses
Aperture
Sensor
CMOS and BSI CMOS
Focusing
Passive Focusing: PDAF and Contrast
Active Focusing :Laser
Flash
LED Flash
Dual Tone Flash
Image Processing
Terms and Words
Extras

3. The lenses in a smartphone camera consists of multiple
layers of wide-angle lenses which all play a role in
focusing light onto the sensor. There are lenses inside the
smartphone camera module that shape the light to fit
the sensor, providing the final focus point, or correcting
inconsistency
Lens configurations
6P Lens
5P Lens
4P Lens
LENSES

4. Aperture is essentially an opening of a lens's
diaphragm through which light passes. It works
much like the iris and pupil of an eye, by
controlling the amount of light which reaches the
retina. A bigger aperture hole lets your
smartphone camera sensor gather more light,
which it needs to produce quality images.
The size of a lens aperture is described by its F-
number, which is calculated using the lens focal
length to the diameter aperture. As such, a larger
F-number refers to a smaller hole, and therefore
less light getting through. This is why smartphone
camera manufacturers brag about larger
apertures, with smaller F-numbers.
APERTURE

5. Most smartphones have a sensor that is on
average 1/3″. The sensor contains millions of
tiny photodetectors which capture information
about the light (photons) hitting them. Every
pixel of the resulting image corresponds to one
photodetector and a million of these
photodetectors correspond to one megapixel.
SENSOR
Product Resolution Image Size Pixel Size
[Type] V = H [µm]
IMX318 22.5M 1/2.6 1
IMX230 21M 1/2.4 1.12
IMX220 21M 1/2.3 1.2
IMX298 16M 1/2.8 1.12
IMX278 13M 1/3.06 1.12
IMX258 13M 1/3.06 1.12
IMX214 13M 1/3.06 1.12

6. Most digital cameras use a CMOS sensor, because CMOS
sensors perform better than CCDs, offering faster speeds
with lower power consumption. Most CMOS sensors
incorporate an integrated circuit
A back-illuminated sensor(BSI or BIS) contains the same elements, but arranges the wiring behind the
photocathode layer by flipping the silicon wafer during manufacturing and then thinning its reverse side so
that light can strike the photocathode layer without passing through the wiring layer.[7] This change can
improve the chance of an input light being captured from about 60% to over 90%
CMOS & BSI

7. PDAF Focusing Technique:
With phase-detection auto-focus, your camera analyses
the light as it passes through the lens. It compares light from
two apertures on opposite sides of the lens. If the image is
properly focussed, the two light rays will give an
overlapping intensity profile. If the image isn’t focussed, the
system can determine exactly how much the focus needs
to be adjusted. It’s then able to focus the image without the
lengthy back-and-forth seen on contrast-detection.
Contrast Detecting Technique:
In order to determine when an image is in focus, your
smartphone uses an algorithm based on measuring the
contrast. Generally, the level of contrast will be highest in an
image when the object is in focus (the image has a sharp
outline and colours are more vivid). If the image is out-of-
focus, colours will tend to blur into each other. This means
there is a lower level of overall contrast.
PDAF Focusing Technique
PDAF & CONTRAST FOCUS

8. Laser Auto Focus Technique:
laser auto-focus is a very different system. It’s known
as active auto-focus as it doesn’t rely on incoming
light. Instead, the phone will emit its own beam of
infrared light towards the object. It calculates the
time for the light to be reflected and is then able to
calculate the distance to the object
Distance travelled by laser beam = Speed of Light * Time to receive reflection
Distance to object = Distance travelled by laser beam / 2
LASER FOCUS

9. The LED flash used on a Smartphone 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
A dual-tone LED flash tries to give more natural looking images in an indoor
environment.
With most dual-LED flashes, there’ll actually be two different LEDs of a slightly
different colour (one with a slightly higher colour temperature and one with a
lower colour temperature). To get the most natural looking photos, your
phone will combine the two flashes and will try to match the colour
temperature of the environment. With the dual-LED ‘True Tone’ flash on the
iPhone, Apple claims to be able to produce more than a thousand different
colours.
The colour of light can be measured by ‘colour temperature’. Sunlight has a colour temperature of approximately 5500°K
To understand how, see the following diagram which shows a range of colour temperatures
FLASH

10. ISP controls autofocus, exposure, and white
balance for the camera system. Recently
correcting for lens imperfections like vignetting
or color shading imparted by the imperfect lens
system has been added, along with things like
HDR recombining, noise reduction, other
filtering, face or object detection, and
conversion between color spaces. There’s
variance between the features that ISP does,
but this is really the controller for getting into a
workable image.
IMAGE PROCESSING

11. Aperture – This is the opening in front of the lens that controls how much light passes through the lens and then to the sensor. Aperture is measured in f-
stops or f-number (e.g. f/1.8, f/2.0, etc.) and the higher the f-number the smaller the aperture and the lower f-numbers.
Aspect Ratio – This refers to the dimensions of your photo. Usually an aspect ratio of 4:3.
Bokeh – This is a photographic technique defined as “the way the lens renders out of focus points of light”
Burst mode – This camera feature allows you to take multiple photos in consecutive order. This is especially useful for moving subjects.
Close-up/Macro mode – This is a smartphone camera shooting mode that allows you to hyperfocus on very small subjects in order to take macro
shots.
Composition – The visual arrangement of the subject and the surrounding elements in a way that tells a story
Focus – This is achieved via a property of the lens that brings the scene into focus by adjustments between the various lenses within the camera module
of a smartphone camera
Autofocus – A camera feature that automatically focuses on the subject
Lens – The lens focuses light sharply onto the sensor to produce an image.
PRO/Manual mode – This is a camera mode that allows you to adjust exposure, white balance, shutter speed, ISO, manual focus, etc.
Megapixel count MP – this refers to the resolution of the pictures taken by a particular smartphone camera. But keep in mind that higher MP count
doesn’t always equate to a higher quality photo.
Optical Image Stabilization (OIS) – A camera feature found on many smartphones that reduces camera shake and helps combat unintended
motion blur.
Pixel size – This is the size of each individual pixel measure in micrometers. The larger the pixel size the more light it can collect and the smaller the less
light it can collect.
Post-processing – This refers to the activities that occur after the photo shoot and before the photo is shared with others.
RAW – This is a file format that is also used by digital cameras which retains all of the image data details which is better for post-processing than the
standard JPEG format since JPEGs lose some data when they compress the image files.
Sensor – Smartphone sensors are of the CMOS type which means ‘Complementary Metal Oxide Semiconductor’; this is the most common sensor in
smartphones due to its high pixel count, lower energy consumption, and lower cost. The larger the sensor, the more light is available to the sensor.
Shutter speed – The speed at which the shutter opens and lets in light to the sensor.
WB (White Balance) – This camera feature allows you to electronically adjust color in your photo. Common options in smartphones include “Daylight”,
“Cloudy”, “Tungsten”, “Fluorescent”.
EXTRAS

12. ‘’The more pictures you see, the better
you are as a photographer’’
Created By-
Sikandar Khan