ISO is a fundamental setting in photography that controls your camera’s sensitivity to light. While it allows you to shoot in low-light conditions, it also introduces noise (grain) at higher values. This guide covers everything from optimal ISO settings for different scenarios to advanced noise reduction techniques in post-processing. We’ll also explore how modern cameras handle ISO, including models from Leica, Nikon, Canon, and Sony, and why high-megapixel sensors manage noise better.
What Is ISO and How Does It Work?
ISO measures the sensitivity of your camera’s sensor (or film) to light. A lower ISO (e.g., 100) produces cleaner images, while a higher ISO (e.g., 6400) brightens photos in low light but adds noise.
When to Use Different ISO Settings
- ISO 50-200 – Ideal for bright daylight, studio photography, or when using a tripod.
- ISO 400-800 – Great for overcast days, indoor shooting with natural light, or fast-moving subjects.
- ISO 1600-3200 – Useful for low-light events (concerts, weddings) where flash isn’t allowed.
- ISO 6400+ – Best for extreme low-light (astrophotography, street photography at night), but expect noise.
For a deeper dive into ISO settings, check out Photography Life’s ISO guide.
How Modern Cameras Handle ISO: Leica, Nikon, Canon, and Sony
Different camera brands and models perform uniquely at high ISO. Here’s a quick comparison:
1. Leica (e.g., Leica M11)
- ISO Range: 64-50,000 (expandable)
- Strengths: Excellent dynamic range at low ISO, minimal noise up to ISO 6400.
- Best For: Street photography and low-light documentary work.
2. Nikon (e.g., Nikon Z9)
- ISO Range: 64-25,600 (expandable to 102,400)
- Strengths: Outstanding high-ISO performance, especially in low-light sports and wildlife photography.
- Best For: Action and night photography.
3. Canon (e.g., Canon EOS R5)
- ISO Range: 100-51,200 (expandable to 102,400)
- Strengths: Great color retention at high ISO, ideal for portraits and events.
- Best For: Wedding and event photography.
4. Sony (e.g., Sony A7 IV)
- ISO Range: 100-51,200 (expandable to 204,800)
- Strengths: Industry-leading noise control, especially in mirrorless cameras.
- Best For: Videography and hybrid shooters.
For detailed ISO performance tests, visit DPReview’s camera comparisons.
Why High-Megapixel Cameras Handle Noise Better
Cameras with higher megapixels (e.g., 45MP+) tend to manage noise better in post-processing because:
- More Pixels = Finer Noise Grain – Noise appears less coarse, making it easier to clean up in software.
- Downsampling Reduces Noise – When resizing high-MP images, noise naturally smooths out.
- Advanced AI Denoising – Tools like Adobe Lightroom’s AI Denoise work better with high-resolution files.
For example, the Sony A7R V (61MP) produces cleaner high-ISO images when downsized than a 24MP camera at the same ISO.
How to Reduce ISO Noise in Post-Processing
Even if your photo has noise, software can help clean it up. Here are the best tools:
1. Adobe Lightroom Classic (AI Denoise, 2023 Update)
- How it works: Uses machine learning to distinguish noise from detail.
- Steps:
- Go to Develop Module → Detail Panel → Denoise.
- Adjust the "Denoise" slider (typically 30-70 works best).
- Compare before/after using the "Before/After" (Y) toggle.
- Best for: RAW files with moderate to high noise.
2. Topaz DeNoise AI
- Why it’s great: Uses deep learning to remove noise while preserving sharpness.
- Best settings:
- "Standard" mode for balanced noise reduction.
- "Low Light" mode for extreme noise (ISO 12,800+).
3. DxO PureRAW
- Key feature: Pre-processes RAW files with advanced noise reduction before editing in Lightroom.
- Best for: High-ISO shots from older cameras.
For a detailed comparison, see PetaPixel’s noise reduction software guide.
Historical Context: ISO in Film vs. Digital
Before digital, ISO (then called ASA or DIN) referred to film sensitivity:
- Low ISO films (ISO 50-100) – Fine grain, needed bright light (used by Ansel Adams for landscapes).
- High ISO films (ISO 800+) – Grainy but great for low light (used by Robert Capa in war photography).
Today, digital ISO is adjustable per shot, unlike film, where you were stuck with one ISO per roll.
Famous Photographers Who Used High ISO Creatively
- Robert Frank – Used high-ISO film for gritty, raw street photography in The Americans.
- Anton Corbijn – High-ISO portraits of musicians (e.g., U2, Depeche Mode) for a moody aesthetic.
- Brassaï – Shot Paris nightlife on high-speed film, embracing grain for atmosphere.
Final Verdict: Should You Always Use the Lowest ISO?
No. While lower ISO gives the cleanest images, sometimes you must raise it to:
- Freeze motion (sports, wildlife).
- Shoot handheld in low light.
- Maintain depth of field when you can’t open the aperture.
Modern cameras and software make high ISO more usable than ever.
Want to Master ISO in Real Life?
If you're in Lisbon, join me for a hands-on photography workshop where we’ll test ISO settings in different lighting. Contact me for details!
For further reading, check out:
Now go shoot—and don’t fear high ISO when needed!