Principles of Photography Lighting: Controlling Camera’s Light Sensitivity

by Aky Joe

in Photography

Light distinct us from the dark world. Light is very important source to various applications, mechanisms and nature itself. Philosophically, Life depends upon Light. (Sigh). Great, now we know that our camera too depends upon light. 😛 Let’s not waste more time and learn more about principles of photography lighting and controlling camera’s light sensitivity.

Principles of Pahotography Lighting-Controlling Cameras Light Sensitivity

What’s Light Sensitivity?

There’s a lot of light in the environment, but it’s barely visible to human eye. The reason is, a human eye being limited with aperture size, focal length and retina light sensitivity. For instance, in nights, the sky appears to be dark grey or black to naked eye, but in real many other colors are present as well. To extract these colors in dark sky, will require an eye to be open for 50-60 minutes without a blink. What? Yes, it’s humanly impossible to keep an eye open for that long and to sense all colors present in sky.

Well, that’s why we use cameras, especially SLR and DSLR cameras, which help us to sense light, adjust aperture size and extract beautiful compositions. Photography Lighting in Camera can be controlled using the ISO Sensitivity Number.

What’s ISO Number in Camera?

To measure light sensitivity levels, ISO (ISO stands for International Organization for Standardization) Number states how sensitive a camera is to light. It also states that, higher the ISO number, more is the camera sensitive to light. In basic cameras, this is also referred to as the film speed, whereas for Digital Cameras this is the ISO Sensitivity Number. ISO Number ranges between 100~6400 (may vary with different camera models). Higher the ISO Number, increases your ability to shoot in low light conditions. In digital cameras, photographers control the light sensitivity via ISO numbers to shoot indoors, nights and other low light scenarios.

How to Control Camera’s Light with ISO Number

You can easily adjust, increase/decrease, the ISO number from your digital camera settings or simply put it on Auto mode. In the Auto-ISO mode, camera sensor automatically detects the light in the subject environment and computes a value on the camera screen or viewfinder. Whereas if you choose the manual adjustment mode, then it totally depends upon the light conditions, shutter speed and aperture size. In the following example, check out our variations of the camera’s light sensitivity, in manual mode:

Camera Light Sensitivity with ISO Number Variations

Auto WB, f/5.6, 1/60s, Canon 1100D

The above example shows different variations of ISO Number for the subject. The subject is shot during the sunset, which shows ISO 100 and ISO 200 images being dark and as the ISO number is increased to ISO 400, the image gets brighter. It’s because the camera’s made more sensitive to light and that light made this image clearer and brighter.

Adjust Camera ISO for Low Light Conditions

When its a low light condition, make sure you slow down the shutter speed, increase the aperture value to f/3.2 or f/5.6 and lastly increase the ISO value from 400 to 1600. Increasing ISO level beyond that will add noise to your image which is also known as grain. But, if the subject is at priority, then you can even touch ISO 6400.

Adjust Camera ISO for High Light Conditions

When it’s a daylight condition, make sure you increase the shutter speed and decrease the ISO to 100. If ISO Number isn’t decreased, it will result into overexposed and burnt images. For shooting subject in sunlight, you may also decrease the aperture value to f/10 or f/14 to achieve depth-of-field and blurred background.

Is that it?

It’s righteously said that professional equipment can’t just make you a professional photographer. But, if your basics are clear, then even a point-to-shoot camera can turn your world upside down. Here’s a list of basic points to help you manipulate light for better exposure.

  • Find a right spot with regards all to the subject you want to shoot.
  • Analyze the subject’s environment and its lighting conditions.
  • When shooting subject in low light conditions, drop shutter speed, increase aperture value and increase ISO Number.
  • When shooting subject in bright light, increase shutter speed, decrease aperture value and drop ISO Number.
  • Shutter speed means how long are you going to expose the camera sensor to capture the subject. (Slowest: 30 s … to … Fastest 1/4000 s)
  • Aperture is the hole which lets the ray of light pass through it, into the camera sensor. ( Largest: f/1 … to … Smallest f/32)
  • ISO Number defines how sensitive your camera is to the light. (Lowest: ISO 100 … to … Highest: ISO 6400)

If I’ve skipped anything above or you’ve a question for me, please use the comment form below to be the part of discussion.

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