Debunking Common Camera Myths About Sensor Size

I want to talk about sensor size, specifically when it comes to cameras, if it’s going to be your first one.

Before we do that, I want to do away with a myth.

Most people assume that when you talk about cameras, you are referring to the device that accurately records a picture of the world around them.

This isn’t true.

I hear this myth repeated to me all the time in one form or another, with the phrase.

I want a camera that takes good pictures.

The truth is, there is no such thing.

All new digital cameras take good pictures. It’s what they were designed to do. Now I’m not talking about security, medical, industrial, or other specialty cameras. I’m talking about cameras designed to take photographs of what people generally take pictures of in the world around themselves.

If all modern cameras take good pictures, why do photographers spend more money on larger sensors? The answer isn't because they magically create better photographs. It's because larger sensors collect more light, and light is information. More information gives photographers more flexibility when conditions become difficult.

It's not usually the camera that's limiting the photograph. More often, it's the photographer's understanding of light, composition, timing, and technique.

So if every modern camera can take a good picture, why do sensor sizes exist at all?

Because photographers aren't buying image quality.

They're buying capability.

And capability usually starts with how much light the sensor can gather.

It's like buying a car. Most modern cars drive well. The difference between them isn't whether they can get you to the grocery store. It's how they perform when conditions become demanding. The same thing is true of camera sensors.

The reason I bring this up is that when you're shopping for a camera, you should stop looking at makes and models first.

You need to look at the features and benefits that you want.

Most people don’t know what they want, so they usually start off with an inexpensive camera system. This isn’t a bad thing. It’s great, especially if you’re not sure if you know what you want and don’t want to spend a lot of money up front. They can then learn about the features and benefits they do want in a camera.

However, some people who do take this route do end up disappointed. Not everyone, but some, because they are expecting to be just as good as the expensive version. Mainly because it has similar features.

Again, all cars have brakes, gas, a steering wheel, and a lot of similar things that make them work. Doesn’t make them equal.

Think of the sensor as the engine in your car. A small four-cylinder engine and a large V8 can both get you to the grocery store. The difference becomes apparent when you're climbing a mountain, towing a trailer, or trying to accelerate quickly. Camera sensors work much the same way. In perfect light, the differences can be surprisingly small. In difficult conditions, those differences become much easier to see.

How much light do you need to gather? The rule of thumb for both. There is no such thing as enough.

Generally, though, the more light you can gather on the sensor or the more horsepower the engine can generate, the more expensive everything is.

Light, or what I call Light Data, is important because the more you have access to, the more detail you can recover in an image. Every photograph is ultimately a collection of light data. The camera isn't recording trees, mountains, birds, or people. It's recording the light reflected from those things. The more light data the sensor captures, the more flexibility you have when editing, recovering shadows, controlling noise, and preserving detail.

Basically, a sensor and its pixels form a net that captures light data, and that information is recorded to a memory card. The bigger the net, the more you can capture. Pixels play a part in this, too, but I’ll get into that later.

There are four sensor sizes currently in use across most modern camera systems. There are a few others, but I’m going to focus primarily on the interchangeable ones first - micro four/thirds, APS-C, full-frame, and medium format. You can think of these as different-sized buckets designed to collect light.

The most commonly used sensor formats are the full frame and the APS-C, followed by the micro four/thirds and the medium format. I could be wrong. I haven’t looked at any sales data in a while, but I’m fairly certain the market is running that way. If anyone has any recent articles, you can email me, and I’ll make a note of them.

If a larger sensor gathers more light data, doesn't that automatically mean a better photograph? Not necessarily. It means the photographer has more information available when they need it. Whether that extra information matters depends entirely on the image being created.

Many professionals work with various sensor-sized cameras, and I can assure you, most people don’t even consider the sensor size. The only ones who tend to ask are other photographers. However, unless those photographers are paying for the shoot, their opinions are simply opinions.

Most clients don't know what or care what sensor size I used. They care whether I delivered the photograph they needed. Sensor size is a tool. Understanding when that tool matters is far more important than simply owning the biggest one available.

Pros and Cons of Sensors

Sensor Size	Micro Four Thirds	APS-C	Full Frame	Medium Format
Advantages	Small and lightweight cameras and lenses. Usually, the most affordable interchangeable-lens systems. Greater apparent reach for wildlife and sports. More depth of field at the same aperture, making it easier to keep subjects in focus.	Good balance of size, performance, and cost. Better low-light performance than Micro Four Thirds. Large selection of cameras and lenses. Popular for hobbyists and professionals alike.	Excellent low-light performance. Greater dynamic range and shadow recovery. Easier to achieve a shallow depth of field and background blur. Widely supported by manufacturers and professionals.	Largest commonly available sensor. Exceptional dynamic range and detail. Outstanding tonal transitions for landscapes, commercial work, and fine art photography.
Disadvantages	Less light gathering ability than larger sensors. More visible noise at high ISO settings. Harder to create extremely blurred backgrounds.	Doesn't gather as much light as a full frame. Some systems have fewer premium lens options than their full-frame counterparts.	Larger and heavier lenses. More expensive camera bodies. Higher overall system cost.	Very expensive. Larger and heavier equipment. Slower autofocus and shooting speeds in many models. Benefits may be difficult to see in everyday photography.

Things to consider

If you primarily shoot...	Travel, hiking, casual photography	Family, portraits, general photography	Weddings and events	Commercial, studio, fine art
Consider	Micro Four Thirds or APS-C	APS-C or Full Frame	Full Frame	Full Frame or Medium Format

Notice that nowhere in these tables does it say "takes better pictures.” Every sensor size involves compromises. A wildlife photographer may prefer Micro Four Thirds because the smaller sensor effectively gives more reach with smaller lenses. A wedding photographer may prefer Full Frame because of its low-light performance. A commercial studio photographer may choose Medium Format because of its incredible detail and dynamic range. The best sensor size isn't the biggest one. It's the one that best supports the kind of photography you actually do.

But what about the number of pixels? Isn't that important too?

It is, just not for the reason most people think.

The myth is that the more pixels, the better the image. That isn’t true either.

The car analogy helps clarify sensor size, but it becomes less effective when explaining pixels. For pixels, it's better to imagine them as buckets. The sensor size decides how much light data or rain you gather, while pixels determine how many buckets you split that rain.

The size of the buckets is more important than their number. A full-frame sensor with 24 million pixels has a fixed size. If the same sensor size has 60 million pixels, each bucket must be smaller to fit all the pixels. This can make each individual pixel gather less light. There are ongoing debates and different technologies related to working around this limit.

Beginning photographers often prioritize the number of pixels over the quality of the light being captured. They assume more pixels automatically means more detail, when that's often not the case.

It’s usually a combination of the sensor size, pixels, the lens, the quality of the light, and the camera’s internal process that brings out the details.

What beginning photographers should be thinking about is the intended use of their photos, so that they can narrow it down to what kind of features and benefits they want in a system.

If you're wondering what most photographers are actually buying today, the market generally breaks down like this:

1. APS-C (Top in Volume): Shipments for cameras with smaller sensors (including APS-C) have increased, posting double-digit growth. The boom in premium compact cameras (e.g., Fujifilm X-Series, Ricoh GR) and highly capable budget/travel bodies (Sony A6700 and Canon EOS R7) makes this the most popular segment.

2. Full-Frame (Revenue Leader): While volume has recently cooled compared to smaller formats, full-frame commands the highest overall monetary value and is the standard for professional hybrids, offering models like the Nikon Z6 III and Sony a7 IV.

3. Micro Four Thirds (MFT): Holds a dedicated, steady niche for videographers, wildlife, and travel photographers seeking ultra-compact telephoto setups, highlighted by systems like the OM System OM-1 Mark II and Panasonic Lumix G9 II.

4. Medium Format (Lowest Volume): Reserved for ultra-high-resolution commercial work (e.g., Hasselblad X2D II 100C or Fujifilm GFX 100S II), this sensor size makes up the smallest fraction of total camera sales due to its high cost and specialized nature.

Shipment numbers can vary depending on how manufacturers and industry groups categorize camera systems, so treat these as broad trends rather than precise rankings.

I am providing these to give you a sense of the sensor. While important, it is not the driving factor for most first-time buyers.

In my opinion, there is too much emphasis on the sensor instead of the technique behind the camera.

Cameras are tools that merely take the data of the world around them.

So which camera takes a good picture? They all do. Which one tells a good story? That's the photographer's job. An AI still can't replace the person standing on a hill with their son, hearing him look over his shoulder and say, "I'm glad you brought me here."

If you can find me a camera that does that, I'll eat my hat.