ISO : Understanding Exposure in Digital Photography

ISO Understanding Exposure In Digital Photography

In today’s editorial, we’ll be looking at ISO as the third primary factor which plays a contributory role in capturing a perfectly exposed image. The first we discussed was Aperture, next we looked at Shutter Speed, and now we’ll be looking at ISO as it relates to Exposure in Digital Photography.

What is ISO?

DSLR Camera sensors have a way of interpreting/responding to light. Their response to light, however, determines how bright or dark the image captured is. This mode or response can be referred to as ISO. ISO is measured in values such as 100,200,400,800 etc and can be controlled automatically or manually via the camera settings.


Like we mentioned earlier, ISO can be used to control the brightness of an image. The higher ISO values you apply, the brighter your image is. But it gets to a certain value where you begin to notice grains on the image; otherwise known as noise. This noise is acceptable by some photographers while some don’t like it. Personally, I don’t┬álike noise in my images. I love them clear and crisp.

ISO Understanding Exposure in Digital Photography
ISO Understanding Exposure in Digital Photography Aperture f/9 Exposure time 1/160 sec ISO 100, Focal length 50mm

To achieve the highest image quality from your DSLR camera, it’s advisable┬áto stick to the Base ISO. The base ISO here is the lowest ISO value your DSLR camera has. Unfortunately, we can’t always stick to this value at all times due to the conditions in which we’re shooting especially in low-light conditions.

What ISO value is best for you?

Pick up your camera and start experimenting. Set your Aperture to around F4 and your shutter speed to about 1/160th sec and ISO set to your base ISO. Start taking pictures with varying ISO values until you get to a point where the noise/grains are unacceptable. That would then give you an idea of the best acceptable ISO value for you to shoot at using your DSLR camera.


This is just a basic knowledge of ISO as related to Exposure in Digital Photography. We’ll go deeper into how it can be controlled when we discuss the Exposure Triangle.



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Author: Forte

Nigerian Wedding, Beauty, Portraits And Fashion Photographer | Cinematographer | 3D Animator | Motion Graphic Artist | Graphic And Web Designer

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