Understanding the Exposure Triangle
What is Aperture, Shutter speed, and ISO and how does these things work together to give you a proper photo?
Photography is more than pointing a camera and pressing a button. Every great image begins with understanding light — and that’s where the exposure triangle comes in.
If you’ve ever taken a photo that looked too dark, too bright, blurry, or grainy, chances are one part of the exposure triangle needed adjustment.
The three elements of exposure are:
Aperture
Shutter Speed
ISO
Together, these settings control how much light enters your camera and how your final image looks creatively. Mastering them is one of the biggest turning points for beginner photographers.
What Is Exposure?
Exposure refers to how bright or dark your image appears. A properly exposed photo contains enough detail in both the highlights and shadows without being overexposed (too bright) or underexposed (too dark).
Your camera controls exposure using three settings that work together like a balancing act.
Think of the exposure triangle as a team:
Aperture controls light and depth of field
Shutter speed controls motion
ISO controls brightness sensitivity
Changing one setting affects the others.
Aperture: Controlling Depth and Light
Aperture refers to the opening inside your lens that allows light into the camera. It’s measured in f-stops such as f/1.8, f/4, or f/16.
How Aperture Works
A low f-number (f/1.8) means a wide opening
More light enters the camera
Background becomes blurry
Great for portraits
A high f-number (f/16) means a narrow opening
Less light enters
More of the image stays sharp
Great for landscapes
Creative Effect of Aperture
Aperture mainly affects depth of field, or how much of the image appears in focus.
Wide Aperture Example
f/1.8
Sharp subject
Soft blurry background
Narrow Aperture Example
f/11
More of the scene stays sharp
Better for landscapes and architecture
I like to think of it this way: the lower the number the less pixels (parts of the image) are going to be in focus. The higher the aperture number, the more pixels are going to be in focus.
Shutter Speed: Freezing or Blurring Motion
Shutter speed controls how long your camera sensor is exposed to light.
Common shutter speeds include:
Fast Shutter Speeds
These freeze motion and are ideal for capturing sports/action or fast moving subjects and wildlife. Some examples of fast shutter speeds are:
1/500
1/1000
1/2000
Slow Shutter Speeds
Slower shutter speeds are useful for capturing the motion rather than freezing it. A lot of creativity can result from slower shutter speeds, such as: waterfall motion, light trails in night photos, and some motion blur during action photography.
Some examples of slower shutter speeds are:
1/30
1 second
10 seconds
Important Tip
Remember that your shutter speed and how it will capture your image depends on the amount of light that is coming in to your lens. The more light there is the higher your shutter speed might have to be in order to freeze your subjects in the photo.
Also, the slower your shutter speed, the more the slightest movement (like a jittery hand) will result in a slightly blurry photo. Using a tripod becomes important at when user slower shutter speeds.
ISO: Your Camera’s Light Sensitivity
ISO controls how sensitive your camera sensor is to light.
Low ISO
ISO 100 or 200
Cleaner image
Less grain/noise
Best for daylight
High ISO
ISO 1600 or higher
Brighter image in dark situations
More digital grain/noise
ISO is extremely useful in low light, but increasing it too much can reduce image quality.
How the Exposure Triangle Works Together
The key to understanding exposure is realizing that all three settings affect one another.
For example:
If you widen your aperture, more light enters the camera
You may need a faster shutter speed or lower ISO to compensate
Or:
If you use a faster shutter speed to freeze action
You may need a wider aperture or higher ISO to keep the image bright enough
Photography is all about balance.
A tip that I learned as I went to make it easier on the go and for those “in the moment I don’t have time to think” shots: If you increase your aperture number by three “clicks” on your dial you either need to decrease your ISO or your shutter speed (not both just one of them) also by three “clicks” on the dial. The same goes for the other settings. If you increase your shutter speed by four “clicks” on your dial, you should decrease your ISO by four “clicks” if you want to keep the same depth of field. If you can’t decrease your ISO or are okay with having a shallower depth of field (or more blurry background) then decrease your aperture by the same amount you just decreased your shutter.
Beginner Exposure Cheat Sheet
Portrait Photography
Aperture: f/1.8–f/2.8
Shutter Speed: 1/200+
ISO: 100–400
Landscape Photography
Aperture: f/8–f/16
Shutter Speed: Depends on lighting
ISO: 100
Sports Photography
Aperture: f/2.8–f/4
Shutter Speed: 1/1000+
ISO: 400–3200
Night Photography
Aperture: Wide open
Shutter Speed: Slow
ISO: Higher as needed
The Best Way to Learn Exposure
The fastest and best way to understand the exposure triangle is through practice. Get out and shoot. Don’t have a purpose or a reason. Just shoot. Pick a random object and do the following:
Put your camera in Manual Mode
Photograph the same subject multiple times
Change only one setting at a time
Compare the results
You’ll quickly begin to see how each setting changes the mood, brightness, and style of your image.
Tip on this: I find it best to bring my computer with me to download and look at the photos right away. Otherwise I get busy and enough time may pass before I am able to get back to them and by that time I forget what I was doing and have to examine the settings a little bit more closely and harder to refresh myself of what I did.
And if you are thinking “I can’t lug around everything with me. Or I don’t have a laptop, just a desktop computer.” well, guess what. You don’t have to go far for this exercise. You could do it right in your living room, although you will have a better understanding if you maybe go out on your front porch or in your own yard where there are plenty of subjects and light to use.
Final Thoughts
Understanding the exposure triangle is one of the most important foundations in photography. Once you learn how aperture, shutter speed, and ISO work together, you gain a greater creative control over your images instead of letting the camera decide everything for you.
Every professional photographer started by learning these same three settings. And every photographer was in your shoes. So don’t feel discouraged and try not to feel overwhelmed.
The more you experiment, the more natural making the changes to your settings will become. But be careful, you might just catch yourself making the changes and feeling proud of yourself…especially when you see the awesome resulting image.
5 Beginner Photography Mistakes (And How to Fix Them Fast)
Starting out in photography can feel overwhelming. You’ve got the camera, the inspiration—but your photos still aren’t turning out how you imagined.
The truth is, most beginners make the same mistakes. The good news? Once you fix them, your photography improves fast.
Let’s break down the most common beginner photography mistakes—and how you can avoid them.
1. Shooting Only in Auto Mode
One of the biggest beginner photography mistakes is relying completely on auto mode. While it’s convenient, it limits your control and creativity of your images.
Why this hurts your photos:
No control over depth of field
Whether everything is in focus or only your subject.
Inconsistent exposure
Your photos will come out over exposed (way too much light) at times or under exposed (way too dark) when you don’t want them to be.
Limited creative flexibility
Being able to control the depth of field and exposure gives you more room for being creative with your photos both in camera and during the editing process.
How to fix it:
Switch to Aperture Priority (A/Av) mode to start learning how settings affect your photos. Aperture priority is a camera mode in which you manually set your aperture, while the camera automatically selects the shutter speed. As for the ISO, aperture priority mode lets you choose whether to set it manually or automatically.
By switching to this mode you will be able to experiment, understand, and master what the aperture does for you easier than if you are in manual mode, which requires you to set the aperture, shutter, and the ISO to get an appropriately exposed image.
2. Ignoring Lighting
To be able to capture the details in the shadow the exposure was raised, but is now too high and is washing out the colors. The photo above and below were shot at the same time of day…around 1pm when the sun was fairly high making the lighting very bright and harsh in comparison to the later afternoon softer sunlight.
To avoid the washout of the colors and to catch the details in the highlights, the photo is now underexposed and some of the details are now lost in the shadows.
Lighting is everything in photography, yet it’s often overlooked by beginners.
Why this is a common photography mistake:
Harsh shadows in midday sun
Washed-out or dull colors
Loss of detail in highlights and shadows
How to fix it:
Shoot during golden hour (the first hour after sunrise and the last hour before sunset) for soft, warm light.
Other beginner photography tips:
Use window light indoors
The windows will act as natural light diffusers—making the harsher outdoor light a little softer.
Avoid direct overhead sunlight
Direct overhead sunlight will give you harsher shadows or no shadows at all, which eliminates some of the depth of your image (makes it look a little 2D and reduces the visual interest of the subject).
3. Poor Composition
The subject in this photo is not clearly recognized. Is it the pot at the very front? The musical instrument at the right? The toys in the sandbox? the items in the background? There is too much going on and nothing leads your eye to a clear subject that tells the story or purpose of the photo.
Even with great lighting, poor composition can ruin a photo.
Why it matters:
Your subject gets lost
Photos feel cluttered
The image lacks impact
How to improve photography composition:
Use the rule of thirds
a compositional guideline that breaks an image down into thirds (both horizontally and vertically) so you have nine pieces and four gridlines (click for example)
Look for leading lines
lines that lead the viewer’s eye from one part of a composition to another. Usually, these lines start at the bottom of the frame and guide the eye upward, from the foreground of the image to the background.
Simplify your background
Less is more. The less you have in your background the better your subject can be focused on.
Another option is to have your background in less focus (more blurry) that your subject.
Ask yourself: What is the subject?
4. Not Checking Focus
In this photo a tripod was not being used to keep the camera steady. When shooting at night the shutter speed has to be slow enough to let enough light through the lens to capture the shot, which means that even the slightest bit of shake can result in a blurry photo.
Blurry photos are one of the most frustrating beginner photography mistakes. I know it was for me.
Why this happens:
Autofocus selects the wrong subject
Camera movement causes blur
Depth of field is too shallow
How to fix it:
Use single-point autofocus instead of one of the multi-point autofocus settings.
Keep your camera steady
Use a tripod, monopod, or remote shutter trigger when you need to and can to reduce the camera shaking or movement created in your hands.
5. Over-editing Photos
This photo was edited at the beginning of Nikole’s photography journey in 2015…when she didn’t really know how to edit and was just trying things to be creative. But in the discovery phase, there were a lot of photos that were way over processed for an aesthetic that wasn’t really all that great looking back…colors are off, skin tones are wonky, details are lost. It’s just not good at all.
Editing can enhance your photos—but too much editing does the opposite.
Why over-editing is a mistake:
Colors look unnatural
Skin tones become unrealistic
Details are lost
How to edit like a pro:
Start with exposure and contrast
Keep colors natural
Make small, subtle adjustments
Keep the edit simple
Conclusion
Every photographer makes mistakes in the beginning—it’s part of the journey. From over processing in 2015, to still getting blurry photos in 2020, and mastering how to capture outdoor photos in the middle of the day in 2025, I am still making mistakes. My journey is still on going and I am learning new things every time I take my camera out.
But by fixing these common beginner photography mistakes, you will be able to:
Take sharper photos more consistently
Improve how you use the lighting in your images
Create more professional-looking images
The key is simple: practice with intention and focus on one skill at a time.
If or when you get frustrated, don’t give up. Take a few minutes to research and reset or just reset. Then keep taking photos, and keep experimenting, and keep learning.
Here are a couple of resources that might help:
Understanding Exposure, Fourth Edition: How to Shoot Great Photographs with Any Camera by Bryan Peterson
The Digital Photography School website
Note: some links in this blog are affiliate links. They help support this blog at no extra cost to you.