Things to know about Smartphone Camera: Exposure Triangle

Things to know about Smartphone Camera: Exposure Triangle

Before reading this article, please check out our techniblogic post regarding megapixels and sensor in camera.

  1. Things to know about Smartphone Camera : Megapixels
  2. Things to know about Smartphone Camera : Sensors
exposure-triangle
via exposureguide.com

When we click a photograph, the exposure determines how light or dark the image will appear and it’s calculated by the three essential settings aperture, shutter speed and ISO. Basically the key to better low light imaging or higher contrast fine quality image is these three feature, which are also knows as exposure triangle. So, let’s take a look on what they are?

Shutter Speed

A shutter speed basically determines when the camera sensor will be open for coming light. there’s an inverse relationship between aperture and shutter speed. A fast shutter speed does not let in as much light as a slow shutter speed. If you’re using a tight aperture to achieve high depth of field, you will need to use a slower shutter speed (for any given light conditions) than you would while using a wide aperture. Shutter speed is also sometimes called exposure time. So, a fast shutter speed means a short exposure time, while a slow shutter speed means a long exposure time.

Shutter Speed Typical Examples
1 – 30+ seconds Specialty night and low-light photos on a tripod
2 – 1/2 second To add a silky look to flowing water
Landscape photos on a tripod for enhanced depth of field
1/2 to 1/30 second To add motion blur to the background of a moving subject
Carefully taken hand-held photos with stabilization
1/50 – 1/100 second Typical hand-held photos without substantial zoom
1/250 – 1/500 second To freeze everyday sports/action subject movement
Hand-held photos with substantial zoom (telephoto lens)
1/1000 – 1/4000 second To freeze extremely fast, up-close subject motion

Shutter speed is measured in fractions of a second, with standard shutter speeds ranging from 1/1000 of a second to one full second.

Effect on Image

Taking a picture of a moving object with a slow shutter speed can create a blurred image of the object (and the suggestion of motion). Using a faster shutter speed makes the object appear more crisply, with better definition and less blurring.

Slow Shutter Speed:

slow-shutter-speed-3-2_resize
via annedarlingphotography.com

Fast Shutter Speed: 

Edgerton_apple
via harding.edu

Can you control your Smartphone’s shutter Speed?

Well, it all depends on your device. There are devices like the LG G4 that offer manual control of shutter speed and many other feature in the stock camera app. If your device doesn’t have any such Pro or Manual mode. Google also integrated a new Camera2 API. This API needs to be properly implemented in your device. Which helps the third party app to manually control your camera. So, try out some other camera app for a change.

What is an Aperture?

Basically, Aperture refers to the width of the shutter opening in a camera when a picture is taken. A wider aperture lets more light in and allows pictures to be taken in dimmer light. However, it also creates shallower depth of focus, so that parts of the picture that are more distant (or closer) than the center of focus will appear out of focus. Depending on what effect you’re looking for, this may or may not be a good thing.

What is an Aperture
via arturogoga.com

The aperture of any camera (not just digital cameras) is measured in terms of “f stop” or “f number.” The technical meaning here involves a 2-based logarithmic scale so that 1 f number difference doubles or halves the amount of light entering the camera.

Aperture Setting Relative Light Example Shutter Speed
f/22 1X 16 seconds
f/16 2X 8 seconds
f/11 4X 4 seconds
f/8.0 8X 2 seconds
f/5.6 16X 1 second
f/4.0 32X 1/2 second
f/2.8 64X 1/4 second
f/2.0 128X 1/8 second
f/1.4 256X 1/15 second

 

How it Looks?

A camera’s aperture setting is what determines a photo’s depth of field (the range of distance over which objects appear in sharp focus). Lower f-stop values correlate with a shallower depth of field.

Narrow Aperture: F/22 photography 

Narrow Aperture: F/22 photography
via f22workshop.com

Wide aperture: F/1.5 photography

Wide aperture: F/1.5 photography
via 35mmc.com

 ISO:

The third factor besides shutter speed and aperture that determines the exposure of a picture is the light sensitivity of the electronic array that takes in the light and forms the picture. This is adjustable in most smartphone’s cameras.

The term “ISO” is taken from an international standard measurement of film speed. While the measurement doesn’t directly apply to digital photography it has been borrowed to do so, and the sensitivity to light is displayed as ISO 200, 400, and so on. The higher the ISO sensitivity, the less light will be required to produce a given exposure. With greater light sensitivity, your camera can produce a given desired picture quality at a faster shutter speed and/or a narrower aperture. This is useful when you are taking pictures in dim lighting and don’t want either the blurred motion effect of a slow shutter speed or the narrow depth of field that results from a wide aperture.

It’s better to leave the ISO in automatic adjust mode, because the pictures are not always suitable for lower or higher ISO. The picture here might help you understand it better.

image-quality-and-iso-sensitivity
via exposureguide.com

 

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