One of the most basic questions people ask when they’re ready to purchase a DSLR camera is whether a full frame sensor is better than a cropped sensor. I suppose they can ask that question backwards as well because everyone has their own priorities. The word “better” is subjective.
In today’s post, I’d like to first identify what a camera sensor is and then after that, I’ll talk a bit about the differences between cropped and full frame sensors. Finally, I’ll discuss some of the pros and cons of each type. Believe it or not, there truly are some characteristics that matter, depending on what your goal with photography is.
What is a Camera Sensor?
An image sensor is the part of a camera that can be considered the brain. Or part of the brain. It’s the piece of technology that detects stimuli from the outside world (the scene) and translates that stimuli into something the rest of the camera can understand. Once the camera understands the information the sensor is transmitting to it, the camera can create an image. In a more specific sense, the sensor converts light waves into signals, or small bursts of signals, that the rest of the camera can use. As you can imagine, there’s a heck of a lot of technology that goes into making a sensor and while I’m sure there are books written on the subject, I’ll leave this definition here.
Functionally, the sensor sits behind the mirror, which sits behind the lens. When you take a photo, the mirror flips up to expose the sensor. It’s the sensor that captures the light in the scene. If you’ve ever removed your lens and looked inside of your camera, it’s the mirror you’re looking at, not the sensor. You’d have to manually lift the mirror to expose the sensor.
Full Framed & Cropped Sensors
While there are many different types of sensors out there that come in a variety of sizes (based on manufacturer), I’ll be discussing the two “types” that you’ll hear of the most. These two are generally called full frame and cropped. Full frame sensors are the same size as a 35mm film frame. So if you remember back to the days of most photographers using film and then remember back to what those frames in the film looked like, you’ll have a good idea of the size of a full frame sensor.
Cropped sensors are smaller than full frame sensors. If you use Photoshop, just think about cropping an image. By cropping, you’re removing area from a photo. The same is true when it comes to cropped sensors. Some of the sensor has been removed, for the lack of a better way to explain this. Basically, they’re just smaller sized sensors.
When you compare the sizes of full frame to cropped sensors, it’s helpful to use something called a crop factor. The crop factor is the ratio between sensor sizes. If you’re starting off with a cropped Canon APS-C sensor, you can say that a full frame sensor is 1.6 times larger than it. You would just multiply the size of the sensor by 1.6 and end up at 35mm. If you were starting off with a full frame sensor and you’d like to find out the size of a micro four thirds sensor that has a crop factor of 2, you’d simply divide 35mm by 2 and you’d have your result.
There are a few truths when it comes to sensor size. In general, when you’re out shopping for a camera, you’ll find that cameras with full frame sensors cost more. That’s just the way it is. It’s like a sliding scale when it comes to this too. The smaller the crop factor, meaning, the larger the sensor, the more expensive the camera. So it you’re looking for something on the less expensive side, check out those smaller sensor cameras. And finally, remember that all cropped sensor sizes aren’t the same. Some have a crop factor of 2, some have a crop factor of 1.5, 1.6 and even 1.3. The closer you get to 1, the closer you get to a full frame sensor. The sizes depend on who makes the camera. Each manufacturer has the favorites. Remember, these rules aren’t hard and fast, they’re merely guidelines.
The Goods & Bads of the Cropped Sensor
Cost
I shoot with a camera that has a cropped sensor. I chose the camera, which happens to be a Canon Rebel T7i, for very specific reasons. There are pros and cons to both cropped and full frame sensor sizes and in these next two sections, I’ll discuss a few of them.
First of all, as I mentioned above, cameras that use cropped sensors cost less. I don’t sell my photography. I mostly use it for blogging and things like that. Mostly posting online. I don’t think I’ve ever printed out one of my photos. Well, back in 2005 I did, but I don’t think that counts. To me, a camera with a cropped sensor is better, simply because of the price. Is it better all around for everyone? Probably not, but it’s better for my specific uses. This price thing is a huge consideration for many people and it’s the reason Canon, Nikon and the others don’t only sell top of the line, full frame cameras. There’s a lot of middle ground that people live on.
Now, don’t get me wrong here. I paid $749 for my camera body, which was and is a lot of money. If someone tells you that $749 isn’t a lot of money, you’ll know that they’re fooling themselves. Even for a camera, for $749, I better be getting a lot. So, it’s not like cropped sensor cameras are cheap, it’s just that they cost less than full framed ones.
Focal Distance
Focal distance is the distance between the lens and the sensor inside of the camera. If you’re using a full frame sensor camera with a 100mm lens, the scene through the camera appears just as it should – one that’s being viewed through a 100mm lens. Now, if you put that same lens on a cropped sensor camera with a crop factor of 1.6, when you look through the camera, the scene will appear as if it’s being view through a 160mm lens. So, the bottom line is, it’s possible to get more distance out of a camera with a cropped sensor than with a full framed one. It’s not better quality distance, but it is more distance, which may be important to some folks. Especially those who are trying to save money on lenses. Zoom lenses can get really pricey and getting more bang for the buck, so to speak, can be exciting.
I went through a phase where I was really into wide angle photography. I bought myself an 11mm wide angle lens and I had all sorts of fun with it. I told everyone I knew that I was shooting with an 11mm lens and got a bunch of oohs and aahs. My friends were impressed. It wasn’t until later that I realized that while I was using an 11mm lens, I wasn’t exactly shooting 11mm shots. Since I was using a camera with a cropped sensor, I learned that my 11mm photographs were actually (11mm x 1.6 crop factor) around 18mm. I’m sure you can imagine my disappointment. But still, they were great photos and I had a lot of fun.
While you get some free distance on the telephoto side, you lose side distance on the wide angle side. Wide angle lenses can be expensive too and you’ll need to think about what type of photography you’re truly interested in. People these days can easily spend more money on lenses than they spend on their camera bodies, so this is an important consideration.
Sensitivity
There’s one thing that cropped sensors are really good at. Actually, they’re good at this, but could be better. That’s dealing with a lot of sunlight. Since the sensors are smaller than their full sized counterparts, they don’t absorb as much light. This can be helpful when doing a lot of outdoor photography. You generally won’t need any type of filter to cut down on the abundant sunshine. Now, I say that these sensors could be better in sunlight because I’ve taken lots of outdoor photos that were overexposed. No camera or sensor is perfect and you’ll always need to make tweaks to the settings on the camera for the best shot.
The Goods & Bads of the Full Frame Sensor
Low Light
Full frame sensors are like sponges; they soak up light. Where is this helpful? In dark and low light situations, such as those indoors at performances, weddings, birthday parties or any other event that’s not in full sunlight or outside. If you’re either a professional photographer or an amateur who is interested in engaging in low light photography, you’ll likely need to pay the extra money and go with a camera that uses a full frame sensor. Compensating for low light with a cropped sensor doesn’t yield the best result. You can slow down the shutter speed, which can cause camera shake or blur, increase the aperture size, which can cause a shallow depth of field or increase the ISO value, which can introduce noise and grain into your images. The easiest and best way to deal with a lack of light is to increase sensor size. Simply put, with a larger sensor, there’s more surface area for the light to touch.
The Math
I don’t know why I get hung up on this so much, but I really don’t like having to calculate the true focal distance I’m shooting at with my cropped sensor camera. As I mentioned above, if I’m taking photos with my 11mm wide angle lens, the fact that I’m not really at 11mm is always in the back of my head. For fun photography, this doesn’t really matter, but I’ve been in situations where the scene called for a specific capture. I like to grab lenses and go and when I’m dealing with something that’s important, I always need to do the math to make sure I’m taking the correct lens along with me. Remember, the lens focal distance needs to be multiplied with the crop factor on cropped sensor cameras to get the true distance. With full frame sensors, you know that whatever it is that’s written on the lens is what you’re shooting with. That’s pretty easy to live with.
Great Wide Angle Quality
Let’s say that I really wanted to get the true 11mm wide angle shot with my cropped sensor camera. What would I have to do? Attach a 7mm wide angle lens to it. Have you ever seen what the glass looks like on some 7mm wide angle lenses? I have and I can tell you that when you take photos with these things, you’re going to get distortion. Much more than is anticipated, all because I had to compensate for the cropped sensor.
With full frame sensors, you can take the wide angle shots and not have to compensate for anything, which may lead to less lens distortion. Of course, a lot of distortion can be corrected in post processing, but it’s much better to avoid it at the source.
Well, there certainly are a lot of considerations to take into account when trying to decide on getting a cropped sensor or a full framed sensor camera. In reality, I think it boils down to price for many of us. Most of us simply aren’t willing to pay for a camera that uses a full frame sensor, especially since cameras that use cropped sensors perform so well. The information I shared above is good to know though, because as your photography skills grow and the time comes for you to upgrade your camera body, you can put this knowledge to good use. If you have any questions regarding today’s post, please let me know in the comment section below. Thanks for reading!
Update:
This is actually a great post. I’ve got some more to add based on my experience and what I tell people who ask me for this type of advice. There are definitely pros and cons to both of these types of sensors and as photographers (amateur or pro), we really need to analyze what we’re ultimately after in order to make the best decisions. I know that sometimes trying to figure out what’s what can be maddening, simply due to the sheer volume of what’s available, but it can be done and we can be completely happy with our purchases.
When considering this topic, we need to first ask a few questions: do I need a full frame camera to be a professional photographer? That one is asked a lot. How about; do I need a full frame camera at all? If I have one, should I upgrade my cropped sensor camera for a full frame? Will I get more background blur with a full frame camera? What about cost? Does a full frame camera cost more than a cropped sensor one? How about the lenses? What about weight? Which weighs more? There are many things to consider and I hope to touch on them in this post.
Full frame sensors are the same exact size of old 35mm film. The size of a full frame sensor (the standard sensor size in digital photography) is 36mm wide by 24mm tall. It’s a 3/2 ratio. Cropped sensors are smaller than full frame ones. Depending on which manufacturer you’re looking at, a full frame sensor may be either 1.5 or 1.6 times larger than a cropped sensor. This is called the crop factor.
In the above photo, the larger red square is the full frame sensor size and the smaller one is the cropped sensor size. Mind you, this cropped size will vary depending on what brand of camera you use. Most camera makers use a 1.5 crop factor while Canon uses a 1.6, which is slightly smaller.
I’m sure you’ve heard these terms many times, but what do they actually mean? Well, let’s pretend we’re taking the photo above. That’s me holding a cup of coffee. With a full frame camera, we’ll be able to capture the entire scene that the lens sees. With a cropped sensor camera though, we’ll only be able to capture part of it. A cropped part, if you will. That would be the part inside the white rectangle. If we were to stretch the center part out so it’s the same size as the full frame image, we’d have two very different photographs. One would be more wide angle while the other would be more zoomed in. Same lenses, different outcomes.
Here’s a question for you: if you use the same 50mm lens on both full and cropped sensor cameras, will you end up with two 50mm photos? The answer is no. On a full frame camera, yes, you’ll have the true 50mm image. On a cropped sensor camera though, the photo will seem as though it was captured with an 80mm lens. Everything in the scene will appear to be more close to the camera, or again, zoomed in on. So if you’re out shooting with a 100mm lens attached to your Canon EOS 5D Mark IV, you’ll be taking true 100mm photographs. If you put that same lens into a Canon EOS 7D, your photographs will seem as if they were taken with a 160mm lens. That’s because with Canon cameras, the crop factor is 1.6. Simply multiply the lens’s focal length by the camera’s crop factor. In this case, that would be 100×1.6-160.
Many Canon cropped sensor cameras (like the Canon Rebel line) come standard with one of two different kit lenses. These are the 18-55mm and the 18-135mm. What isn’t readily known though is that when shooting with either of these lenses, you’re not shooting at the focal length you think you are. On a cropped sensor camera, you’re actually shooting at 28×88 and 28×216 respectively. Here’s another question: Is this change in focal length a good thing? Well, that would depend on how you shoot and what your intentions are. If you like far away telephoto shots (nature, wildlife, sports), then yes, a cropped sensor camera may be right for you. Because telephoto lenses are so expensive, you may be getting more bang for your buck because you’ll be able to zoom in so much more with this type of camera. I actually own a Canon 300mm lens and with one of my cropped sensor cameras, I’m getting a 480mm result. That’s not bad and it’s quite the bargain.
Also, when it comes to macro photography, cropped sensors can help greatly because they’ll allow you to get much closer to whatever it is you’re taking a picture of. After all, we can only get so close to something and having an extra boost is nice.
Let’s discuss background blur for a moment because this topic is usually top of mind for many photographers. The question is, do full frame cameras offer more background blur than cropped sensor cameras? The answer is, everything else being equal, yes they do. There is a whole heck of a lot that goes into this reasoning and I’m not even going to try to go into it here, but just know that you’ll end of with more background blur with a full frame camera. I want to stress that everything else needs to be equal though, so keep that in mind.
If you wanted to compensate for this “lack of background blur” with a cropped sensor camera, all you would need to do is change your lens and aperture setting. If you’re shooting with an 85mm lens at a f/1.5 aperture with a full frame, you’d need to shoot with a 56mm lens at an aperture size of f/1.2 on a cropped sensor camera. Again, all you need to do to find of what you need is to multiply (or divide) the full frame specs by, in this case, divide by 1.5 (or whatever the crop factor is).
Here’s another example. If you’re using a full frame camera and have a 160mm lens attached to it at f/6, to get a similar photo on a cropped sensor camera, you’ll need to use a 100mm lens at f/4. Simple math.
To clarify what I wrote above – the larger sensor isn’t the absolute reason you’ll be able to achieve more background blur in your photos. The real reason is that most lenses are manufactured for full frame cameras. These lenses work well with full sized sensors. As you can see from what I shared above, to achieve the same blur with a cropped sensor, you’ll need to open up your aperture and in many cases, that’s simply not possible or is cost prohibitive. If you’ve been shopping around for a while, you know how expensive large aperture lenses can be. When you get down toward the lower ends of things (larger apertures), it can get pricey fast.
How about lighting? Does a full frame sensor perform better in low light? Yes it does. Why? Because, if you have the same amount of pixels on each sensor, each pixel size on the full frame sensor will be larger than its counterpart. Think about each pixel as an ice cream scooper. A bigger scooper will scoop more ice cream. A bigger pixel scoops more light. And what does more light mean? Less noise. Or grain. Whatever you’d like to call it.
I think the elephant in the room here is price. How do full frame cameras compare to their cropped sensor camera counterparts when it comes to what you’ll spend. Full frame cameras cost more. They’re larger and heavier and there’s just more camera to pay for. That increases the price. There’s also more electronics involved, which boosts the price as well. When it comes to lenses, those made for full frame cameras generally cost more as well. So when purchasing a camera, especially as a beginner, you really need to think about how often you’ll be using it, what you’ll be shooting, and how much your photos matter. If you’re going into business for yourself and you’ll be taking photos for clients who will be paying you, you’ll likely want to spend the money on a full frame sensor. But if you want to take pictures of your kids for the sake of keeping memories or to share on social media, you might want to consider a cropped sensor.
Let’s talk about camera weight now. To make a long story short, most full frame cameras weigh more than cropped sensor cameras. If we look at the Canon 5D Mark IV (full frame), we’ll see that the weight comes in at 31.4 ounces. Now if we look at the Canon SL2 (cropped sensor), the weight comes in at 15.98 ounces. That’s a big difference. Obviously this extreme type of example won’t always hold true, but in general, there’s a fairly distinct weight difference. And again, the same holds true when it comes to lenses. Full frame lenses are generally larger and heavier than cropped sensor lenses, so be prepared for a pretty big camera and lens combo if you decide to go in that direction.
Okay, that’s all I have for right now. I hope I offered some additional information to this post and if anyone else has anything to add, please do below. Thanks!
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