There are quite a few different camera sensor size options available today. This is both a good and a bad thing. The good thing is that along with the wide range of sensor sizes comes cameras for almost any budget. The bad thing is, hardly anyone knows what differences in sensor size means. Seriously. Have you ever asked an amateur photographer what size their camera sensor is? I can almost guarantee that if you did, you’d get a blank stare 95% of the time. This is a tragedy because the sensor is arguably the most important aspect of a digital camera.
For this post, I’ll assume you’re already familiar with camera sensors, in and of themselves. I’ll begin the discussion around size. Check out this graphic below to learn about many different camera sensor sizes and how they compare to one another. I got the graphic from PhotoSeek.

If you’re into the Canon Rebel line of cameras, you’re looking at cameras that use APS-C sensors, which are quite a bit smaller than a full frame sensor. If you’re using your smart phone for photography, you’re using a sensor that’s about five times smaller than the Rebel sensor. The question is, does sensor size actually matter when it comes to photography or video? Actually, it does. And in this post, I’ll explain why.
What Are the Best Camera Sensors?
I think most professional and skilled amateur photographers and cinematographers would agree that full frame sensors are the best. These sensors measure around 36×24 cm. Beyond this, there are sensors called Medium Format, which measure around 54×40 cm. These are quite rare though and are reserved for high end professional use. I suppose the question most people have after learning which sensor size is best is – why? Why are larger full frame camera sensors better than smaller ones? Well, it comes down to a few things with light being the most important.
If a camera sensor is small, it doesn’t have much surface area to acquire the light it needs to form a high quality photograph or video file. If you’ve ever tried to record a video with your smart phone or GoPro in low light, you’ve likely quickly learned what grain, or noise, is. Noise is all those little specks you see in your image. The reason there’s noise is because the phone or small camera lacked light. And because it lacked light, it had to amplify the light it did receive, which resulted in a lower quality photo or video. Large sensors have much more surface area that can be used to collect the light the camera needs to form a quality image. And because there’s so much surface area, the camera needs to do very little, if any, artificial amplification.
It’s All in the Pixels
I’m sure you’ve heard of megapixels. If not, these are the things that capture light on a camera sensor. The thing is, not all pixels are the same size. You can have a Micro 4:3 sensor that’s 16 mega pixels and a full frame sensor that’s also 16 mega pixels. At first glance, you’d think these two are comparable. What you’re missing though is that the full frame pixels are larger than the Micro 4:3 pixels, allowing the full frame sensor to absorb much more light, which will result in a higher quality image. Also, because so much more light is being captured with the full frame, the dynamic range will be greater as well, again, resulting in a higher quality photo or video.
Simply put, a larger sensor with larger pixels will allow more light to be absorbed, resulting in a better signal to the camera’s brain. The stronger the signal, the less amplification the camera will need to do, resulting in less noise. Also, because more light is hitting the camera’s sensor, the better the low light performance will be.
Crop Factor
You may have heard of something called a crop factor, but if you haven’t, I’ll explain what it is. Actually, if you look at the graphic above, you’ll get a decent idea. For full frame cameras, you’ll see an entire scene through your lens. With a cropped sensor, you’ll only see a portion of that same scene through your lens. Depending on what size sensor you’re using, your scene will be cropped by a certain factor. For Canon APS-C sensors, you’d need to add 1.6 times area to see the same thing a full frame camera would see. It’s strange, I know. And really it’s not something the amateur ever thinks about. It’s only when you engage in your photography or video taking for a while that you begin needing more. More light. More scene. More everything. It’s at this point you’ll begin looking for higher end cameras that can offer you that more. Be prepared to spend more though because full frame camera aren’t cheap.
What About Video?
When it comes to video, sensor size is less important than when compared to photography. If you can structure your scenes in decent light and open your lens’s aperture up wide, you can get some great footage. But if you require more scene surface area and if you like to shoot in low light and at night, you’re going to need to bump up to a full frame. It’s just the way it is. So you’ll need to decide how serious you are about what you’re doing and what your budget is.
What’s my advice? Well, it’s to get yourself a DSLR camera with a full frame sensor. If you did that, you’d experience some distinct advantages over cameras with cropped sensors. These advantages are:
– Better depth of field performance.
– Better low light performance.
– Better dynamic range.
– Lower diffraction.
Be warned though – there are some distinct disadvantages to owning one of these cameras. They are:
– These cameras are expensive.
– These cameras are big and heavy.
– These cameras use bigger, heavier, and more expensive gear (lenses, etc…).
Again, bigger sensors are definitely better than smaller ones, but they come at a price. If you plan on going pro though, you’ll likely need to upgrade. If you’ve been shooting for a while, you’ll certainly know when the time is right.
What’s your opinion on camera sensor size when it comes to photography and video? Do you think it matters? What do you own? How’s the quality you’ve been able to produce? I’d love to read about all that below.
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