ISO doesn’t matter, and here is why

For years, photographers have been told to keep their ISO as low as possible to avoid noise. Many stick religiously to ISO 100, thinking it’s the golden rule for cleaner images. But here’s the twist: with today’s cameras, ISO doesn’t matter as much as we’ve been led to believe. In fact, embracing higher ISO settings can be a game-changer. In his latest video, Will of PhotographyExplained will guide you through this perspective and help you get rid of the “high ISO anxiety” (yes, I just made this expression up).

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The biggest ISO misconception

One of the biggest misconceptions about ISO, as Will points out, is that it makes your camera sensor more sensitive to light. This idea stems from the film days but doesn’t apply to digital photography. Instead, ISO acts as a brightness amplifier. Your camera sensor collects light, and when you increase ISO, you amplify the signal already captured, making your image appear brighter. However, this doesn’t mean you’re capturing more light—it’s simply a post-exposure adjustment.

Will uses an interesting analogy to explain this: imagine your camera sensor is like a bucket collecting rain, or in this case, light. No matter what ISO setting you choose, the size of the bucket—or the sensor’s ability to collect light—remains the same. Increasing ISO doesn’t let the bucket catch more rain; it just amplifies the amount of rain already collected. This analogy highlights how ISO brightens your image without increasing the actual light captured.

The truth about noise

Many fear high ISO settings because of noise—those grainy specks that can detract from an image. But ISO itself doesn’t create noise; it amplifies the existing noise from low-light conditions. Will explains this with another analogy: amplifying a whisper in a noisy room. You’re boosting the desired signal but also the unwanted background noise. Modern cameras, however, are incredibly adept at managing noise, even at high ISO settings, allowing you to capture clean, detailed images that would have been impossible a decade ago.

ISO invariance: a game-changer

ISO invariance is a feature in many modern cameras where boosting brightness in post-production yields nearly identical results to increasing ISO in-camera. Will suggests testing your camera’s ISO invariance by taking a shot at ISO 6400 and another at ISO 100, then brightening the latter in post-production. If the noise levels are similar, your camera is ISO invariant, offering greater flexibility.

Why base ISO still matters

While ISO isn’t as critical as it once was, base ISO (typically ISO 100) still delivers the highest image quality. At this setting, your camera produces maximum dynamic range and minimal noise. However, Will emphasizes that clinging to base ISO in all situations can hinder your photography. For instance, capturing fast action or shooting in low light often necessitates higher ISO settings to avoid blurry or underexposed images. The slight trade-off in noise or dynamic range is often worth getting the shot.

The myth of extended ISO

Extended ISO settings, like ISO 50 or ISO 100,000, sound impressive but are achieved through digital trickery. Will explains that these settings artificially brighten or darken an image without adding any real advantage. Instead, focus on your camera’s native ISO range for optimal results.

Noise reduction in post: The ultimate backup

If you’re still worried about noise, specialized tools like Topaz DeNoise AI and Lightroom’s noise reduction can work wonders. These tools analyze and separate noise from image details, leaving you with sharper, cleaner photos. Will notes that while they’re not a substitute for proper exposure, they provide peace of mind when shooting at higher ISOs. I personally rely on Lightroom’s Denoise after shooting concerts in poorly-lit clubs with my even poorer Nikon D7000. It truly is a game-changer!

Embrace the high ISO

Finally, a little bit of noise isn’t inherently bad. In fact, it can even add character and texture to your images, almost like film grain. More importantly, your audience cares about the story your photo tells, not the technical imperfections.

After all, ISO is an essential part of the exposure triangle, and it’s meant for you to tweak it so you can achieve the best possible result in any given situation. So, Will challenges you to push your ISO limits and see what your camera can achieve. The result might surprise you.

[ISO Doesn’t Matter. Here is why. | PhotographyExplained]