Today you will learn the main things you need to know about the differences between crop sensor cameras and full frame cameras.
Full frame vs Crop sensor camera
So what is a full frame camera?
A full frame camera is a camera that has a full frame sensor. What this means is that the sensor for the camera is the equivalent in size as a 35mm film, which is 36mmx24mm. This gives an aspect ratio of 3:2.
Each individual frame of traditional 35mm film is this size and the diagonal is about 43mm. This is simply an image sensor format sometimes known as 35mm format.
If you look at the DSLR and mirrorless camera market, you will find full frame cameras more on the high end with just the body for these cameras starting at prices over $1000.
Now before we go on to explain what this means in terms of performance, let’s quickly define what a crop sensor camera is.
*Think of full frame as an “original size” or “reference size”.*
So what is a crop sensor camera?
A crop sensor is any sensor that is smaller than the standard for a full frame sensor which is the 35mm film frame.
People keep talking about APS-C. What is it?
An APS-C camera is a camera with a sensor which is roughly equivalent to 25.1mm x 16.1mm which is the size of Advanced Photo System film negative in Classic Format. This is where you get the name APS-C from. It is just one of the most common crop sensor formats which is why you might hear it quite a lot when people are talking about crop sensor cameras.
This gives you an aspect ratio of 3:2 for the image.
Sensors that are of this size or equivalent are found in many DSLRs and mirrorless cameras but with quite a few variations. You will find APS-C sensors in low to mid range cameras on the market.
APS-C cameras are just one type of crop sensor camera.
I still don’t understand the difference between full frame and crop sensor?
In short, a full frame sensor is bigger than a crop sensor.
So you know that one difference is the size, but what significance does this have?
Well one key feature is the crop factor.
Since a crop sensor is smaller, it has a crop factor.
Crop factor – also known as focal length multiplier or format factor.
It is the ratio of the diagonal length between a crop sensor and a full frame sensor.
If a crop factor is 1.6 then the full frame sensor is 1.6 times longer diagonally compared to the crop sensor version.
This crop factor influences the look of your images and this will be discussed below. But first, here’s a quick example to just show how crop factor is worked out.
Example : Using Canon APS-C vs Canon full frame.
Crop sensor size for Canon APS-C: 22.3mm x 14.9mm
Full frame sensor for Canon: 36mm x 24mm
Diagonal length APS-C: 26.7mm
Diagonal length Canon full frame: 43.2mm
Crop factor/ focal length multiplier/ format factor
= 43.2mm/26.7mm = 1.62 ≈ 1.6
Different cameras from different manufacturers may have different sensors resulting in different crop factors.
Here is a list of common crop factors for different devices.
- Canon EF-S / EF-M = 1.6x
- Nikon DX = 1.5x
- Nikon CX = 2.7x
- Panasonic & Olympus micro four thirds = 2.0x
- Sony E-mount = 1.5x
- Sgma foveon DC = 1.5x or 1.7x
How does crop factor affect your image?
Equivalent focal length
The crop factor changes the effective focal length of your lens.
This is because you take the crop factor and multiply it by the focal length on the lens to give you the actual equivalent focal length if it was a full frame camera.
For example, say you have a 50mm lens but your camera has a crop factor of 1.6 then your effective focal length is 80mm instead.
Because an 80mm is more zoomed in than a 50mm lens, your resulting image for the same lens on a full frame vs crop sensor camera will look different.
So if you took a picture, the crop sensor camera will produce a magnified version of the image created by the full frame camera.
What about the image quality of crop sensors and full frame sensors?
Are crop sensor cameras REALLY that NOISY?
Yes and no. But first of all let’s briefly describe what we mean by noise. We don’t mean your neighbours. By noise we are talking about that grainy look you get if you bump your ISO really high when you’re in low light.
How does the sensor size effect noise?
When it comes to image noise, the one thing that will affect it the most is the sensor size of the camera. This is because image noise is dependent on how much light a sensor can capture.
Now let’s break it down simply without getting into any complex maths.
We are going to look at a full frame sensor and a crop sensor which are both 24 megapixel sensors.
Both have the same number of megapixels. The full frame sensor is larger than the crop sensor.
Now let’s use an analogy. You have a room which is a certain size and let’s call this room A.
We will treat room A as the full frame sensor.
Now we have another room which is smaller than room A in size. This second room will be called room B. We will treat room B as the crop sensor.
Now let’s introduce some people to act as megapixels. (don’t worry it’ll start to make sense)
Let’s say we put 24 people in room A and 24 people in room B and every person is an equal distance away from each other…
..Pixels need space
In room A each person has more room around them without touching another person compared to room B. There is the same amount of people, but more space in room A.
So going back to the real thing. On a full frame sensor each pixel has more space between itself and the nearest other pixel compared to a crop sensor (or room B).
Why does the space between pixels matter?
It matters because the more space there is between pixels the more light they can capture.
So the effective light collection area per pixel in a full frame camera is higher than a crop sensor camera.
Tell me already…is a full frame or crop sensor better for image quality?
Because of this, given everything else is kept equal, a full frame camera should perform better in low light situations when it comes to image noise compared to a crop sensor camera.
So if you took a full frame camera and a crop sensor camera and took the same picture from the same spot in the same lighting and the same ISO (let’s say we use ISO 3200); then the full frame camera should produce less noise in your final image.
Even though full frame cameras should outperform crop sensor cameras in low light, in well lit conditions modern crop sensor cameras actually perform pretty well. As long as you are not moving into high ISO levels then you will not really see a noticeable difference in noise.
Something else to consider is the lenses that you can use with your camera.
Will my lens work on a full frame or crop sensor camera?
Lenses are designed specifically for full frame or crop sensor cameras. Because of this they will have various mounts depending on the system you are using. We don’t need to go into detail about mounts but, the mount type is just the way a lens and a camera is connected. It determines which cameras and lenses can fit and work together. Different camera brands tend to use different lens mounts that don’t overlap.
So a Canon lens would not fit a Sony camera and vice versa.
For example, if we look at Canon’s DSLR range they have the EF-S lenses which are designed for crop sensors.
On the other hand, you also have the Canon EF lenses which are designed for full frame cameras but can ALSO be used on Canon’s crop sensor cameras.
So EF lenses can be used on ALL EF or EF-S cameras by Canon.
BUT EF-S lenses will NOT fit Canon’s full frame cameras. They are ONLY to be used with EF-S mount cameras which are just the crop sensor Canon cameras.
Basically DON’T USE AN EF-S lens on A FULL FRAME CAMERA.
To know which lens type you need you can simply put in your camera model name and mount type into google and you should find it pretty quickly.
So, should I buy a crop sensor camera or full-frame camera?
So now that you know a bit more about the differences between full-frame and crop sensor cameras, you might be asking which you should go for. You are smart so you probably already have some ideas, but we will summarise some of the ideas.
Who should use a crop sensor camera?
The first thing to note is that on average they will be cheaper than full-frame, so most beginners will be looking at an APS-C camera for their first camera as full frame cameras require a much larger budget.
In practice, APS-C can be good for situations where you need to get close up to the subject and need that extra zoom. Examples can include sports or wildlife photography when you need a close up photo of a subject (e.g. an eagle in flight in the sky) so you need a very high equivalent focal length.
Also if you won’t be doing much photography in dark settings then the image quality advantages of a full frame are a bit irrelevant.
In short, for beginners or hobbyists, crop sensor is perfect in most cases. Unless you just happen to have a big budget then go for full frame.
Who should use a full frame camera?
Again budget matters, if you have a bigger budget for your gear a full frame is more accessible.
Also if you need to get as much into a frame as possible then full frame can be better. Think of situations where you may need a wider angle like a landscape where you need to capture a lot of foreground as well as background.
If you will be shooting a lot in low light situations then you may want to go full frame for the added benefit of less noise. Maybe you shoot in dark indoor settings or shoot a lot at night then available light could be harder to find.
In short, for the high end of the market or for professionals, full frame cameras are perfect or you could just be an enthusiast with a decent budget.
Full frame cameras:
- Are more expensive
- Perform better in low light (produce less image noise).
- Can ONLY use lenses made for full frame cameras
- Can achieve a wider angle of view because they have NO crop factor
Crop sensor cameras:
- Cheaper to buy, better for beginner budgets.
- Not as good in low light compared to full frame, but still pretty good in well lit conditions.
- Can use lenses made for BOTH full frame and crop sensor cameras
- Can achieve more zoom due to crop factor on lenses.
If you have a bigger budget or are a professional you will probably be looking at getting yourself a full frame camera. Otherwise get a crop sensor camera and you will be fine.
We hope this article helped you!
- Photography Pursuits Team