Exposure Triangle Trainer & Cheat Sheet

What is the Exposure Triangle?

The Exposure Triangle is a visual representation of how three key camera settings — ISO, Aperture, and Shutter Speed — work together to control exposure. Think of it like a 3-legged stool: adjust one, and the others often have to compensate to keep the photo balanced in brightness and effect.

ISO – Light Sensitivity

ISO determines how sensitive your camera's sensor is to light. Lower ISO values (like ISO 100) mean less sensitivity, resulting in cleaner, sharper images — ideal for bright conditions. Higher ISOs (like ISO 3200) increase light sensitivity but introduce digital noise (grain), which can reduce image quality.

• ISO 100–200: Best for bright, outdoor scenes. Cleanest results with least noise.
• ISO 400–800: Great for cloudy days or indoor shooting with decent light.
• ISO 1600+: Necessary in low-light or night photography, but expect some graininess.

Pro Tip: Always use the lowest ISO possible while still maintaining proper exposure — it's a key step toward image quality!

Aperture – Depth of Field

Aperture refers to the size of the opening in your lens, measured in f-stops (e.g., f/2.8, f/8). A lower f-stop number means a wider opening and a shallower depth of field (less in focus). A higher f-stop means a narrower opening and a deeper depth of field (more in focus).

• f/1.4–f/2.8: Wide open — perfect for dreamy portraits with blurred backgrounds.
• f/4–f/5.6: Balanced — great for street photography and casual portraits.
• f/8–f/16: Narrow — ideal for landscapes where you want everything sharp.

Fun Fact: Aperture not only affects depth of field but also how much light hits your sensor. Wider = more light. Narrower = less light. It's a creative tool and technical setting in one.

Shutter Speed – Motion Control

Shutter speed is how long your camera's shutter stays open when you take a photo. It's measured in fractions of a second (like 1/1000s) or full seconds for long exposures. Faster shutter speeds freeze motion, while slower speeds introduce blur — either intentional or accidental!

• 1/1000s–1/500s: Super fast — great for freezing action like sports or wildlife.
• 1/250s–1/60s: Safe zone for handheld shooting, depending on your focal length.
• 1/30s–1s: Slow shutter territory — use a tripod! Great for creative effects like light trails or silky waterfalls.

Quick Tip: The rule of thumb is to use a shutter speed at least 1/focal length to avoid blur. For a 50mm lens, use 1/50s or faster if you're not using a tripod.

ND Filters – Neutral Density

ND (Neutral Density) filters are like sunglasses for your lens. They block some of the light, which lets you use slower shutter speeds or wider apertures even in bright conditions. This opens up creative options like motion blur in daylight or shallow depth of field in sunshine.

• Use slower shutter speeds: ND filters allow long exposures of waterfalls, waves, or moving crowds — even in full sun.
• Use wider apertures: Shoot portraits at f/2.8 in bright light without overexposing.

They’re labeled by strength — for example, an ND2 cuts 1 stop of light, ND8 cuts 3 stops, and ND1000 can block up to 10 stops. The darker the filter, the more light it blocks.

Pro Hack: Combine ND filters with a tripod for dramatic effects. It’s how photographers get those dreamy long exposure shots!

Balancing Tips

• To brighten: Raise ISO, open aperture (lower f-number), or slow shutter speed.
• To darken: Lower ISO, narrow aperture (higher f-number), or speed up shutter.

Mastering exposure is all about trade-offs. Want shallow depth of field? You'll need to balance that with shutter and ISO. Want to freeze motion? That means less light, so adjust ISO or aperture. It’s all connected — and now you know how.