What Is Crop Factor? (Understanding The Complexities)

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What Is The Crop Factor

I still remember the first time I got my camera, and a friend told me to be aware of what the difference between a full frame and an APS-C sensor is.

Back then, I was not really sure what that statement meant, but over time, I have grown to realize that there are a lot of different sensors within the camera range, as well, and the crop factor is a major part of this whole situation.

If you have been wondering what is crop factor, we are going to help you have an understanding about that in this article, so you have an easier time.

What Is Crop Factor?

Now, a lot of the times, people are not aware of what the crop factor is to begin with. However, it is not at all difficult to understand, to be honest. Quite the opposite. A crop factor is very simple to understand. It simply refers to the ratio of the sensor size to the 35mm sensor or full frame sensor.

I know, it actually is a lot simpler to understand. You see, sensors are available in a number of sizes, with the 35mm being the most common one and also known as a full-frame sensor.

35mm full frame Sensor vs Crop Sensor

It has dimensions of 24mm x 36mm. Whereas a common crop sensor comes with the dimensions of 25.1 x 16.7 mm, you can clearly see the difference here.

Now, on paper, it might look like it should not make any difference, but the reality is different as the crop factor actually makes a significant difference in the cameras and how they produce images, or videos, for that matter.

How To Calculate Crop Factor?

Now, when you are calculating the crop factor, the process is not as difficult as it might seem. It actually is a lot easier, to be honest. What you have to do is know the physical size of the sensor.

The first thing that you do is calculate the diagonal using the Pythagorean Theorem, and once that is done, you then divide the number by the diagonal of the crop sensor.

So, here is a way to figure out the crop factor of Canon’s APS-C cameras.

  • Canon Full Frame/35mm: 36² + 24² = 1872, so the diagonal would be 43.27.
  • Canon APS-C/Crop sensor: 22.5² + 15² = 731.25, so the diagonal would be 27.04.
  • So, the crop factor for Canon’s APS-C camera would be. 1.600 or 1.6x.

Remember, different cameras have different dimensions for their crop sensors, but in almost all the cases, the full-size sensor always has the same dimensions . Therefore, the process is rather easy.

However, if you want it to be easier, you can just search the crop factor of the camera, and that should give another understanding.

There Are Apps Available For Calculating Crop Factors

Now that we are done talking about how you can calculate crop factors, I actually would understand if some people are having a tough time doing it the right way.

Now, it is very important to understand that not everyone is going to run into the issue, but if you want, there are apps you can use on your phone to actually go ahead and calculate the crop factor by yourself.

Thankfully, all the camera manufacturers are very transparent when it comes to the crop factor, and therefore, they mention the already calculated crop factor on the specifications sheet.

All you have to do is just multiply the focal length of the lens with the crop factor, and you will get the effective focal length of that specific lens. It is not at all confusing, but thankfully, you would be able to get all the information about crop factors with ease.

There Are Different Types Of Crop Factors

Now, when you are in the market looking at a camera, you will see that there are offerings from various camera manufacturers that come in a number of crop factors.

image of dslr camera on table

This makes the whole experience a lot more confusing for the average buyer because they end up wondering just what exactly does it even mean.

Thankfully, it is not at all confusing, as you can just do a quick search on the spec sheet, and you will figure it out, but for those who are wondering, I am going to list down some of the most common crop factors below.

  • Micro Four Thirds: 1.84 – 2x.
  • Canon APS-C: 1.6x.
  • General APS-C: 1.5x.
  • APS-H: 1.3x.
  • Medium Format: 0.64x.

These are some of the most common crop factors that you are going to find in most of the cameras that are available in the market. When buying a camera, always be mindful of this before you go ahead and spend money.

Why Is Crop Factor Important?

Honestly, I have been taking pictures for as long as I can remember, and I realized that in the first few years, I did have some issues with the crop factor because using a 50mm lens on a 1.6x camera gave it an almost 85mm factor, and while it was difficult to adjust in the start, I have come to realize that when you are good at taking pictures, and you understand how these lenses and crop factor work, then it really will not be an issue.

Honestly, I have seen so many photographers still using crop factor cameras because they are very comfortable with it, and they know how to master it, as well.

What Makes Crop Sensor Cameras Worth Buying?

More often than not, when you are looking for photography advice, you will come across people who will tell you to invest in a crop sensor camera rather than a full-frame camera.

This is especially there if you are just starting out, and I used to think about it a lot until I realized that buying a crop factor camera is a lot better for beginners because if you just want to learn photography, you can do so with ease with a crops sensor camera.

portrait of rail
Image Credits: Fotis Fotopoulos

These cameras are also cheaper, use the same lenses, and will give you the same image quality, provided you know how to take pictures in the first place. There is absolutely nothing wrong with crop sensor cameras, and there is a whole market for these.

There Are Drawbacks To Crop Sensor Cameras

When you are talking about the drawbacks of crop sensor cameras, I will be honest; I do not remember the last time I ran into issues with these cameras. However, I would still like to address a few, so you know what you are getting into.

For starters, the only major drawback that comes from a crop sensor is the crop factor itself. For instance, if you are using a 50mm lens on a crop sensor camera, the focal length becomes 80mm.

This means that you will now have to have more distance between you and the subject so you can properly take the picture. If you can overcome that issue, then there are no drawbacks.

How Does Sensor Size Affect Focal Length?

Yes, for those wondering, the sensor does affect the focal length of the lens you are getting. For instance, if you are using a 50mm lens on a full-frame camera, the effective focal length will still be 50mm due to the 1.0x crop factor of the 35mm sensor.

image of Canon APS C camera

However, if you are using the same lens on a Canon APS-C camera that has a crop factor of 1.6x, then the 50mm will be multiplied with the crop factor, giving you 80mm of effective focal length. In the case of a zoom lens, the crop factor will then apply to all the focal lengths of the lens that you are using.

Do Smaller Sensors Always Mean Worse Performance?

No, not really. Smaller sensors do not always mean worse performance. As a matter of fact, these sensors are used a lot more common than one might think and have been around for a long time.


The point here is that if you have been looking for a good camera in general and you do not want to spend a lot of money, getting your hands on a crop sensor camera is a lot better choice and will get you better results overall.

Your Author

  • Celebrating childhood in photographs and emotions through photos. My aim is to transfer all my photography experience by sharing useful camera-related guides and individual reviews so you can get an idea about everything before buying.

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