The Exposure Triangle: Understanding ISO, Shutter Speed & Aperture Once and For All

 

The Exposure Triangle: Master ISO, Shutter Speed, and Aperture in 2026

Stepping out of "Auto Mode" is terrifying, but it's the only way to get those professional, blurry-background, or crisp-action shots you see on Instagram.

To do that, you need to master the three pillars of photography: Aperture, Shutter Speed, and ISO. Think of them as a three-way tug-of-war—when you change one, the others have to react.

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1. Aperture: The "Eye" of the Lens

Aperture is the size of the opening in your lens. It’s measured in "f-stops" (like f/1.8 or f/11).

Low f-number (f/1.8, f/2.8): Large opening. Lets in TONS of light. It creates that beautiful "Bokeh" (blurry background) that makes portraits pop.

Low Aperture because the background is very blurry

High f-number (f/8, f/16): Small opening. Lets in less light. Everything from the flower in front of you to the mountain in the back will be sharp and in focus.

High Aperture because everything in the frame is very sharp

The Hack: Smaller number = Blurrier background.

If you are shooting a portrait with a really blurry background use a really small number = f4 or f2.8.

If you are shooting an areal/landscape photo use a higher number to get everything sharp = f10 or f12.

 

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 2. Shutter Speed: The "Time" Keeper

This is how long your camera’s "curtain" stays open to let light hit the sensor. It’s measured in fractions of a second (like 1/1000 or 1/30).

 

• Fast Shutter (1/1000): Freezes time. Perfect for sports, birds, or a splashing wave.
  
  
  
  

Fast Shutter because you can catch a drop

• Slow Shutter (1/30 or lower): Creates motion blur. Use this for those "milky" waterfall shots or light trails in the city. (Warning: You’ll need a tripod for this!)
  
  
  
  

Slow Shutter because you see the milky waterfall

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 3. ISO: The "Sensitivity" Boost

ISO makes your camera sensor more sensitive to light. It’s your "emergency" light when it’s too dark to get a good shot.

• Low ISO (100-400): Best for bright sunny days. Clean, crisp images.
  
  

• High ISO (3200+): Essential for night shots or indoor events. It brightens the image but introduces "Noise" or grain. In 2026, modern cameras handle high ISO much better, so don't be afraid to use it if you have to!

Some cameras also have a native ISO which means your camera performs at it's best at their native ISO. E.g. my Sony A7CII has a native ISO for video at 800 or 3200. So I always try to use these ISO numbers whenever I shoot video.

Modern Full Frame Cameras are able to handle ISO up to 10.000 or 20.000 pretty smooth. If you go a lot higher you will see a lot of noise or grain in the footage.

But modern editing programs like Lightroom or DaVinci Resolve are able to reduce noise very good in post production.

Noise or Grain in a photo

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 4. How They Work Together (The Secret Sauce)

Imagine you are in a dark room. You want a bright photo. You have three choices:

• Open the Aperture: (Lower the f-stop) to let more light in physically.

• Slow the Shutter: Keep the "window" open longer to catch more light.

• Boost the ISO: Make the camera "try harder" to see in the dark.

The goal is balance. If you want a blurry background (Aperture), you’ll have a lot of light coming in, so you’ll need a fast Shutter Speed to balance it out so the photo isn't completely white.

 

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 5. My 2026 Cheat Sheet

Still confused? Save this simple guide for your next shoot:

 

1. Portraits: f/1.8 | ISO 100 | Shutter 1/250
   
   

2. Landscapes: f/11 | ISO 100 | Shutter 1/60 (on a tripod)
   
   

3. Action/Sports: f/4 | ISO 400 | Shutter 1/1000
   
   

4. Night/Stars: f/2.8 | ISO 3200 | Shutter 15 seconds

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6. Final Thoughts

Don't try to learn this all at once. Put your camera in **Aperture Priority (Av or A)** mode first. You pick the aperture (background blur), and let the camera figure out the rest. Once you’re comfortable, flip that dial to **Manual** and take full control of your art.

Mostly it's just try and error. You will figure it out very soon. As with everything the more you try the more you learn.

Here you will find all my Photography and Videography tips.