Outdoor Photography How To

Many photographers believe that high ISO camera settings are the root cause of photos with unsightly noise, so don't feel too bad if you suffer from this familiar misconception. Instructor Mark Dumbleton explains why "that's not entirely true" and addresses what he insists are the real culprits.

Dumbleton is a successful South African wildlife photographer whose popular YouTube channel is devoted to camera techniques and editing tutorials for inexperienced photographers. This 10-minute episode is super simple because he only  relies upon a minimum of technical details to explain the concept of noise while comparing the implications of high ISO to other key considerations that some photographers ignore.

The video kicks off with the following statement about the relationship between ISO and noise: "It's one of most misunderstood ideas in photography and in this video I'm going to prove it and show you what actually causes the problem." He also provides some great advice for capturing clean images in low light, when it's often necessary to bump up ISO values to get the light right.

Dumbleton says the misunderstanding often begins with the Exposure Triangle that's frequently used to determine images with a perfect balance of shutter speed, aperture, and ISO. But here's the problem with this seemingly simple guide: "ISO is always explained as something that controls brightness. This may make sense on the surface, but it's misleading"

It helps to think of exposure as the amount of light that reaches your camera's sensor, and Dumbleton explains that this is controlled by two variables (not three); namely, aperture and shutter speed. "Wide apertures let in more light, while fast shutter speeds only permits a quick burst of light to hit the sensor." Small apertures and slow shutter speeds do the opposite.

Then comes ISO, and Dumbleton says this is where most people get things wrong: As he says, "ISO controls how much the camera amplifies the captured light signal. So when you raise ISO you're not capturing more light."

The remainder of this eye-opening lesson is devoted to practical implcations of the foregoing explanations and will likely change your approach to exposure in the future. You can find other valuable how-videos like this one on Dumbleton's instructional YouTube channel.

And be sure not to miss the tutorial we featured with another experienced wildlife photographer who provides a comprehensive beginners guide to bird photography with simple gear—covering everything from camera settings and composition tips to easily mastered shooting techniques.