Difference between Full-frame Sensors and Crop Sensors

 
This image gives a visual demonstration of the crop difference between a full-frame camera and a crop sensor camera.

This image gives a visual demonstration of the crop difference between a full-frame camera and a crop sensor camera.

Buying a camera is a big investment and no small decision. There are many elements and specs to consider and research. One factor of picking a camera is deciding whether to get a full frame (more appropriately called a 35mm frame size) or a crop sensor camera and you may easily overlook it if you're not aware it's an option. I say that you may be overlooking it, because it's not actually something you would ever notice without looking for it or being able to compare it beside the opposite style. So in this article I'm going to cover what it is and some pros and cons to each to hopefully help you understand them better. So lets get to it.

What Are Full-Frame and Crop-Frame Sensors

First, to know what is happening, we need to have a basic understanding of what is happening between lens and sensor. First, although hopefully obvious, it should be said that not all sensors are the same. Just because both your phone and your DSLR are 12 megapixels, does not mean the sensors are equal. Resolution has very little to do with the sensor quality. The sensor size however, can make a big difference. This is typically most correlated to the fact that the individual light receptors (photosites) can be slightly larger. This helps in numerous ways, but largely for better ISO handling. Furthermore, as the feature image of this post shows, sensor size affects the crop/focal length. This is due to the focus length angle that the lenses must be able to create in order to have the image properly fill the whole sensor. As you can see in my beautiful illustration below, due to the sensor size differences, the angles of incoming light must change. This inherently means the possible perspective angles (regardless of lens focal length at this point) are different between sensor sizes. This is very basic explanation and the lens manufactures probably cringe and the rudimentary nature of this post (forgive me you fine lens makers). 

A basic illustration of how the camera sensor size can affect perspective angles and crop ratios.

A basic illustration of how the camera sensor size can affect perspective angles and crop ratios.

So, to recap, not all sensors are equal for many reasons and as the size changes, so do many elements of the camera. Let's look at pros and cons to both, starting with Full-frame cameras.

 

Pros to Full Frame

1)  Low light capabilities - because full frame cameras actually have larger sensors, larger photosites, and have to use larger lenses, they collect light better (in laymen terms). This allows them to do really well in low light conditions.

2)  Low ISO Noise - because of what I just stated above, they also handle ISO beautifully! You can use higher noise than on a crop sensor and still get low noise. Due to this, many full frame cameras will also have larger ISO ranges. 

3)  Wide angle- without the 1.5x crop magnification you can get a lot wider angle. This and the listed benefits above are part of why full frames are so popular for landscape, arcitecture, etc, because they can get really wide angles.  For example, an 18-55mm kit lenses on a 1.5x crop-sensor is actually acting as a 27-82.5mm lens (focal length x 1.5 crop magnification = virtual focal length). However, on a full frame camera, an 18mm lens is actually shooting at 18mm.

4)  Dynamic Range - full frame cameras also tend to have greater dynamic ranges. They capture more detail in shadows and highlights. This also slightly affects color. You can get more correct colors (assuming you can take a proper exposure to begin with) and give you smooth colors due to details captured.

5) Depth of Field - full-frame sensors have a more shallow depth of field than crop sensors. This can allow you to capture more of that nice bokeh and set your subject apart from the background more. Keep in mind, this point still depends your lens, aperture, focal length, and distance from subject. But it does have some affect.

6) Last, but not least, they just look impressive. (hehe, my favorite!). No one likes feeling like the smallest camera out there (sometimes).

Pros to Crop-Sensor

1) Magnification - the crop sensor magnification can actually be a great thing. Crop sensors are sometimes preferred for sports, wildlife, etc. because a 300mm lens on a 1.5x crop is suddenly acting as a 450mm lens. It actually allows you to get a little closer crop without loss of resolution and that can be desirable depending on what you're shooting

2) Depth of Field - Crop sensors have quite a high depth of field. This could allow you to catch sharper details in both foreground and background. So opposite of having a super-shallow DOF with a lot of blur in the background. Again, this point still depends your lens, aperture, focal length, and distance from subject. But it does have some affect.

3)  Cost - They're a lot cheaper than full frame cameras. Ranging from $300 for entry level to $1,200 for better models. Full frame cameras on the other hand typically start closer to $2,000 and can get up to around $6,000 or more.

4) Weight - They're also lighter than full frame cameras. Lenses are slightly smaller, smaller bodies, and smaller parts inside.

5) Lenses - You have a wide variety of lenses to choose from. You can use either a full-frame or crop-sensor lens on a crop-sensor lens, but the opposite is not true. If you use a crop sensor lens on a full-frame camera, you will get a black border where the image doesn't reach the edge of the sensor.

Cons to Full-Frame

1) Cost - They're expensive. Because of the way the sensors are produced, the cost gets bumped up a lot. Again, they can get up to $6,000 for the body only. My Nikon D600, which I've absolutely loved, was only roughly $1,400 and is still an amazing beast of a camera body. I know also have the Nikon D750 which is also amazing, but closer to the $2,000 range.

2) Weight - Some people may not mind, but they are heavier. Add a heavy lens and a long day of shooting a wedding and you've  got your workout for the day in.

3) Lens Availability - There aren't as many FX (full-frame designation for Nikon) lenses available, however most FX lenses are high quality. A full frame lens will work on a crop sensor, but a crop sensor lens (DX) will not work on a full frame camera. You will get major lens vignette around all your images. FX lenses are made larger to handle the larger sensor, but there's not as large a variety like there is for crop sensor cameras.

4) The wide angle of view - Again, this is only a drawback depending on what you are shooting. If you're trying to shoot wildlife and sports where you want to be as zoomed in as possible without loss of quality, get a crop-sensor. But if you're wanting those wide angle perspectives, use a full-frame camera.

Summary

I'm not going to do cons for the crop sensor because you get the idea. If I've already said something about one, then the inverse is probably true for the other type.

So hopefully that helped give you a bit more info on the differences between the two. If you found this article helpful or interesting, please share it with friends and family by using the share buttons below. Thank you.

 

David Wahlman does photo and video production for outdoor and active lifestyle industries. To learn more about him, view his About Me page.