Sensor Size


Camera Buyer's Guide


Lesson Info

Sensor Size

Let's talk about the sensor size. One of the most important features arguably, the most important feature on a camera is the sensor. And one of the most important aspects on that is how big or small is that sensor, 'cause as you saw in the early example, the difference between an interchangeable lens camera and your phone was one of the big differences in image quality was the sensor size. The sensor is the item that has replaced film in our cameras, it is the device if we were to pull off the lens on an SLR and open the mirror and go behind the shutter, this is what is recording the light and turning light into an electrical signal that is being recorded into our digital image. The important thing to know is that there are a lot of different size sensors out on the market and it's gonna have a fairly profound impact on the types of equipment that you can use, the lenses you will use, the quality of image that you will get. And the trade off simply goes between choosing a large sensor ...

which does a very good job at acquiring light and giving you a lot of high resolution, but it's also comes at a big cost at a very large camera in some cases. Now, the largest of the common sizes available today is based off of 35mm film. What's magic about 35mm film? It was really popular, that's about it. It was just a perfect Goldilocks size when it comes between having the camera that you can carry over your shoulder pretty comfortably, and a camera that could produce an enlargement that you could turn into a poster. That's what worked out well for film and as photographers made that transition from digital or from film to digital, it was a really nice system where you could just buy a new camera and use your whole collection of lenses. For historical reasons, full frame, or sensors based on 35mm frame size is a standard that photographers still talk about quite a bit even though there are very few people shooting 35mm film anymore. I know you're out there and that's great, I love it, keep shooting film, but the most part, that's the system that we're gonna be basing a lot of our numbers and our lingo and the way we talk in photography. But the manufacturers have made smaller size sensors so they can make smaller cameras with a different set of features. It's kinda like the engine in a car, they make cars with different size engines so that they can do different things. They have different names, APS-C is a little bit smaller, both Canon and Nikon have those as well as other manufacturers. Four Thirds is a little bit smaller yet, that's used by Olympus and Panasonic. Many of the point and shoot cameras, the better ones are using something called the one inch sensor which just as a little side note, there is nothing one inch about a one inch sensor. That is the name of the sensor, it is not the size of the sensor. If you wanna know why, I will explain that in my fundamentals of photography class, it's too long for this one. There are a variety of other small point and shoots and of course phones which are gonna have much much smaller sensors. With smaller size sensors, the pixels are smaller, and they're not as good at gathering light. So you kinda wanna get the largest size sensor that fits your needs. I am not happy with the titles of these sensors because we have words, we have letters, we have numbers, and none of it makes sense to somebody who is new to photography, so in my classes, and I don't think anyone else does this, in my classes, I measure them the same way we measure our TVs and computer screens, which is just measuring them from corner to corner. Now you can get a feel for, okay, 43mm versus 28, I can tell what the difference is in size. Now when we're talking about interchangeable lenses, we're gonna be mostly talking about these four groupings of cameras, full frame, APS-C and the Four Thirds system. When you have a full frame camera, which has a 43mm sensor in size, measured diagonally, you can find cameras from Canon, Nikon, Sony, Leica and Pentax, that offer this as an option. If you want a 1.5 crop, that's available from Nikon, Sony, Pentax, Fuji, and Leica as well. It's a little bit smaller in size, and this is known to have a 1.5 crop factor, because it is smaller than the full frame by a factor of 1.5. I hate to throw a lot of math on you, but if you take 43 and 28, it's a 1.5 times difference between those two. We'll talk more about that as we get into the lenses and the effects of using the different size sensors. Canon decided to do something slightly different that has a ever so slight more crop to it, so it's considered a 1.6 crop. The Four Thirds cameras use something that is notably smaller, so that they could have a camera system that was notably smaller than the other big cameras out on the market. The sensor size is gonna have a big impact on the types of lenses that we choose and what we get in the view finder. Let's take a look at how this impacts the actual photos that you're taking. Let's imagine a full frame sensor. We're gonna use a large sensor and we're pointed out at the dock here, and we have this nice big beautiful scene in front of us. What would happen if we were shooting with a crop frame camera rather than a full frame camera. Let's switch it over to a crop frame camera. You will see that our camera still pointed at the same subject but it's slightly different in its angle of view. They are similar views between the two, but the full frame is seen more from side to side. There is a cropped magnified view that you're getting when you have that crop size sensor. This was a problem in the early days of digital because we didn't have lenses design for these new sensors. Everything was designed for the 35mm standard. This picture was taken with a 16 to 35 lens at 16mm, which is a very wide angle setting. If you wanted to get the same picture with a crop frame sensor because let's just say that's the camera you had, you can do it but you need a slightly different lens. You would need a 10 to 22mm lens, shooting it at 10mm, and it's because of our little math problem. It's a smaller size sensor, by a factor of 1. and so 16mm on full frame is the equivalent of 10mm on the crop frame sensor. This is one of the most confusing aspects for people getting into photography, and it's because different size sensors are gonna capture different angles of view with the same lens. It's just something that you kinda have to work through and the more you do it, the better you'll get at this. Originally, this was a big downside to these crop frame sensors. Because you couldn't get the wide angle 'cause they didn't have wide angle lenses. But now, wide angle lenses are very common, and you can shoot almost as easily wide in the crop frame as the full frame. But because full frame is what all the professionals are shooting, there are a few more options for those of you who are into extremely wide angle views, might be landscape photographers, or people doing architecture or real estate, the full frame is gonna have some advantages there. Now let's view this once again from a different perspective. We're up in Alaska and we're shooting wildlife. If we have a full frame camera, and the subject's just a little bit further away, we have a lot of empty space around that subject. If we were using a crop frame camera with the exact same lens, the pixels on our sensor would be more on our subject that we're concentrating on. This is where crop frame cameras have a distinct advantage as any time you are shooting telephoto. People shooting wildlife, sports, birds, anything that's far away with telephoto lenses, it's gonna be easier and cheaper to do with a crop frame camera. If you wanted to take a photograph like this, with a crop frame sensor, like a 1.6 crop, you could probably do it with a 300mm lens and here's some of the stats. Nine inches length, 2.5 pounds, gonna cost you around $1,400. As we talk more and more about crop and full frame sensors, you're gonna get the idea that full frame sensors are higher quality and that's true. You will get higher quality with full frame sensor but, there's always a but, you need a better lens to make that happen on that bigger sensor. What sort of lens do you need? If you wanna get that same type shot, we take our 300mm, we multiply it by our crop factor and this is the lens that we need. We need a 480, and you're in luck, because there's a number of manufacturers that make 500mm lenses. Granted, they're twice the length, three times the weight and seven times the price, you can get a little better photo. If you want a good photo of a whale jumping out of the water, a crop frame sensor and a 300 is gonna do you a good job. If you're willing to spend a lot more money, you can do a little bit better if you're trying to compete with the absolute top professionals from National Geographic out there with the big 500mm lens. For most people, it's probably not worth that upgrade there for that particular scenario, but it's an option for those of you who financially want it. When it comes to sensor size, let's just think about bigger versus smaller. What does that mean? Bigger means in general, not always, but in general, you're gonna get bigger pixels that are better at recording clean information of light. You're gonna get more pixels, in general, not always, but you're generally gonna have more space for getting more pixels for more resolution. You're gonna get an overall better image quality, 'cause you're collecting more light through the camera. And it's gonna work better under low light condition. If you were a wedding photographer and you're gonna be shooting under the low lights of a reception hall, most professional wedding photographers are going to have a full frame sensor, because that's what does the best job in that sort of condition. The smaller size sensors have some benefits to them. We get a smaller camera size. Less electronics, less sensor size, we could have also smaller lenses, which can be a fact. The smaller lenses can be a big impact there. It's gonna be less weight because everything is smaller, and in general it's gonna cost a little bit less money. And so, let me do another example for you here. I showed you the 100 to 400 earlier from Canon and this is for a full frame sensor. I told you that mirrorless does not save any size. The sensor size will mean that there's a different size lens and so the Panasonic and Olympus Four Thirds system has their own 100, 400. To be honest with you, these are not totally 100% equal, there's a slight difference in light. This one from Canon is gonna let in a bit more light, it's not much though, they're very very equal lenses. This is how much size you will save from a full frame to the Four Thirds sensor, and that's just on this one particular lens. I'm gonna see if I have any other particular, let's see if I have, here's another good example. If we were to go with a normal 50mm lens, a normal lens with a Four Thirds system versus a normal lens with a 35mm system. Now, granted, this is a really high quality lens for a full frame system, but you know what? This is also a really good lens for the Four Thirds system. When you go with a smaller size sensor, all of your lenses get to be a little bit smaller. You do compromise a little bit in image quality because this on a large size sensor is gonna take better quality images than this. How much difference? Well, in marginal light condition, it's gonna be a little bit better, enlargements, it's gonna be a little bit better, but you know what, for most people, the Four Thirds system would be probably totally fine in most everything that they do. Alright, let's get these carefully back on here. Alright, so let's do some closer examination of different size sensors in some particular cases 'cause I know some people want some case studies. What about this sensor versus that sensor? This is probably one of the most asked for comparisons. What's the difference between a full frame sensor and a crop frame sensor in what it does? This is a sensor that's 43mm diagonally across versus one that is 28. It's called an APS-C sensor, because there is a system back in the late 90s called the Advanced Photo System and this was the size of film that was used in that very short lived film system. If we're comparing the sizes, it's 36 by 24mm, and 16 by 24mm. If you wanna go off of image area, how much land do we have? The full frame is 225% the size, the APS-C is 44% the size, so it's less than half the area, and that's why there's kind of a pretty big difference in the price and the types of equipment that you can use with these. I like doing sports photography, and doing sports photography you need a telephoto lens that lets in a lot of light. One standard would be, okay, let me get a full frame camera and I need a lens that has a seven degree angle of view with an aperture of 2.8. If you have that, you could shoot basketball in an indoor arena and do quite well. Alright? With a full frame camera, it's gonna cost you almost $10,000 to do that with that angle of view at that aperture. If you said, well wait a minute, let me see what it would cost with a crop frame camera. These are not totally apples and apples comparisons. This is the closest camera from Canon to the 5D Mark IV, and the 200mm lens is a different lens but it has the same angle of view and it has the same aperture settings so when you're actually out there on the court shooting shots, you're gonna be at the same shutter speed, and the same aperture, and the same ISO, getting very much the same shots. At $2,100 versus $9,400. Which one is gonna take better photos? In most cases the full frame camera. There's a lot of little give and takes. One of the things here is that the 7D Mark II shoots at 10 frames a second, and the 5D Mark IV, shots at I believe 8 frames a second. There's gonna be a few things that the 7D Mark II gets that the other camera doesn't get. But the lens system over there is just much more expensive. This is the idea between, should I get an APS-C system, or a full frame system? It's gonna cost you quite a bit more if you wanna upgrade to full frame. Let's try another scenario. This time let's go with Nikon, and let's just go, I just wanna get a good general camera with a couple of all purpose lenses. If you were coming in and asking me for my advice, I'd say well the Nikon D7500 is a great all around camera. If you wanna go full frame, I'd look at the D750. That's a good all around camera, but with the full frame sensor. As far as the lenses, I'm gonna recommend slightly different lenses that are appropriate to the cameras that you use. So you're looking at a package of a little under $3, with a crop frame camera. And if you said, well you know what, I got a little extra money. I got a little extra Christmas bonus at work and maybe I can upgrade to a full frame camera. Can I do that for $500? Well you might be able to upgrade the camera, but you're gonna have to upgrade the lenses as well. And when we put the whole package together, let's take a look at what we're gonna get into, we're gonna get into little bit different lenses that are gonna cost a little bit more money, the camera's a bit more money and suddenly you've doubled the price of what you've done. So the price of going full frame jumps up quite a bit. And I do recommend full frame for a lot of people, but you need to have the budget to do it. The worse thing to do is to buy a full frame camera, and then buy garbage lenses or not have what you need in lenses, unless you know that you're gonna be able to afford lenses shortly down the road. I remember when the first full frame cameras that were kind of affordable came out, people just upgraded their cameras, they didn't upgrade their lenses, and then they were complaining about the qualities not really any better than I had before. That's 'cause you need to upgrade the whole package. BacK when I was a kid and everybody had to have a stereo system, you can't just have a good turntable, you gotta have good speakers and a good amplifier. Can't just buy one thing and think you're solving the problem. And it's very important balance between cameras and lenses in this case. Let's do another scenario. This time, let's compare full frame, 1.5 crop frame, and the Four Thirds system. Let's say we wanna have a pro zoom kit. When I say pro zoom kit, I'm talking about two lenses that have an aperture of f/2.8, so they let in a lot of light. This is the type of thing that a wedding photographer would have or a news photographer would have, and I've chosen a body that is a good body, but not the top of the line nor the bottom of the line body. In this case, I'm going with the Canon 6D Mark II and a couple of lenses that have a max aperture of 2.8. What I'm curious at is how much is this gonna cost me in money and in weight? Alright, now let's compare a similar system with a crop frame system. In this case, I'm gonna use Fuji X-T2 as an example which is an excellent camera from Fuji. They do make a couple of pro zoom lenses that are different apertures to fit the different size sensor in it. When we check out the price and the cost to this, price and the weight of this, you'll notice that there's a notable savings difference because we've gone to a smaller size sensor which has less cost throughout everything we're doing. Now let's jump down to the Four Thirds sensor, which is a smaller sensor, smaller lenses, slightly different focal lengths but it's still that same 2.8 maximum aperture. All of these lenses are near identical when it comes to the angle of view and how much light they're letting in as far as what shutter speed and aperture you're gonna end up shooting with, and when we look at the price and the weight of this, you can see that the price and the weight come down noticeably from this. For an average consumer, somebody just interested in getting into photography, I think the Four Thirds system is a really good system. I think the APS-C system is probably the best system for most people who don't mind carrying a little bit of extra weight with them. And if you really wanna get serious, then there is the full frame. There is one thing that I know some of the technical guys out there, the nerds, that they are just, they're screaming at their computer right now. Some of you don't hear them, I hear them screaming. They're very loud over on this side of the, I can feel them. What they're screaming at is that these aren't the same. I didn't first said they were exactly the same. They're equivalent in their angle of view, and in their aperture setting, but one of the big difference is, is that they don't have the same depth of field. Alright, depth of field is a really important aspect in photography, and if you're shooting portrait photography, it's gonna look vastly different with all three of these. So you know what, I did a test, and I can show you how much difference, because there is a difference, and I'll let you be the judge of how much difference there is. When you're shooting a portrait, and you're shooting with shallow depth of field, you want your subject in focus, but you want the background out of focus. This is a shot with a Four Thirds sensor. My subject's in focus and the building and the foliage is out of focus. So what I wanna do is compare what this would look like with different lenses. When we shoot it with a APS-C sensor and then a full frame sensor. Okay, try not to look at the pretty girl, I want you to look at the blurry background and how blurry the background is. And you'll notice that the full frame sensor is able to blur out the background more. For people who do portrait photography, who do senior potraits, wedding photography, this is a very important aspect which is one of the reasons why they use larger size sensors. If you do a lot of portrait photography, it's something to consider that the larger the sensor, the more you're gonna be able to blow that background out of focus, which means that your subject is gonna stand out from that background. This is one of the big differences between taking pictures with your phone and taking pictures with an interchangeable lens camera. You're really able to get nice shallow depth of field. How much of a difference is it for the average photographer? Most of the time, it really depends on how much you shoot portrait and want that shallow depth of field. It is a great tool to have and I love using it from time to time. Our three common sizes of sensor, 43, 28 and 22. Let's compare some of the things. Number one, you're gonna get the best quality with the full size sensor. It's gonna be the best under low light. It's gonna be part of the largest system, because this is the system that's been around for many many years and it is without a doubt the favorite of professional photographers in almost all genres because it's such a well established system. This next one is a little bit, you know, shaky, on exactly the numbers but you can use ISO settings up to 12,800 and still get very clean usable results for most any practical purpose that you would have with most photographs. Stepping down in size, I think is probably gonna get you the best value, so if you are value minded, you wanna look at that medium size sensor. This is also gonna be really good for sports and wildlife because those long lenses become much more affordable. In the whole system, it's gonna cost probably half what the full frame system is. The downside to this is the top good ISO is gonna be a step lower than full frame. Shooting at 6,400 is relatively uncommon for most people and so it's gonna cover pretty much most user's needs virtually all the time. I will rarely ever go over ISO 3,200 in what I shoot. And then there's the Four Thirds system which is definitely gonna be the most compact and lightest weight so if you are into travel photography, or backpacking or bicycle touring or anything where weight and size is really limited, then this Four Thirds size can be really nice. And the image quality from this is still very good. Not as good as the others, but it's still very good, and I'm happy to use this in many situations myself. The top good ISO is gonna be probably closer to around 3, so it's gpnna be a step lower and you know what, in two or three years, I'm gonna raise this number to double that, but then I'm gonna probably raising all of them so as one gets better, they all tend to get better at the same time. I think it's probably time to check in with Kenna and see if there's any questions I can address. Question about medium format sensors, and where those fit in with regard to this world that we've been talking about. Well my guess is that anyone who's looking at medium format sensors is gonna know almost everything I talk about in this class, and so for those of you who don't know, back in the old days of film, there was small which was 35mm, 110, little things like that, then there was this medium format film which used film about this size, and then there was large format film. So there is small, medium and large. Medium format, these days, means anything larger than a full frame sensor. Fuji, Leica, Phase One, Hasselblad, are a number of the more popular manufacturers that make full frame or make medium format cameras. They're fantastic and they're kind of, if we go back to the car analogy, those are the Ferraris and the Lamborghinis and it's a little beyond the scope of your average buyer, which is why I've chosen not to include it in this class. It just gets into a different realm. Just in case you're wondering, the bottom price to get into that is around six to $7,000, camera body only, lenses are usually three to $5,000 a piece depending on the brand. I had to draw a limit on the bottom and the top and I'm sorry but I'm gonna put them there, for a good reason. Well thank you, just good to understand and know what the medium format sensor is. It's bigger than the full frame. Okay, question from Brenda H. is, is there any difference in image quality if you put a full frame lens on a crop frame camera? Right, okay. For a lot of the legacy systems that had been around for awhile, for instance, Nikon and Canon, take this little Nikon right here. Nikon uses a crop frame camera, so this has a 1.5 crop sensor, but one of the big advantages of this is that you can use Nikon's entire line of full frame lenses and what happens is it projects an image that's a little oversized, but that doesn't cause any problems at all. There's no problem with using a full frame sensor on a crop frame camera. As I said, there's nothing wrong with it, you're kind of not using the lens to its full capability, but there's nothing wrong with it, you'll get perfectly sharp photos, no problem. Great, thank you. Okay, so clarification, this is for Renato, when we were talking about Four Thirds sensors, so regarding the Four Thirds sensor camera lens and has 2x crop factor, are the aperture sizes of these lenses doubled as well? Is there any correlation between the crop factor and how the aperture, does that change? For example, is a 25mm 1.4 equal to a 50mm 2.8? Right, so this is an area that a lot of people can get confused and it can get very very tricky. We just pull one item here out here. So this is the Four Thirds normal lens, which is a 25mm lens, and I will pull the, this is a 50mm sigma lens, and these are the exact same in their angle of view, and they are exact same in their aperture, their maximum aperture of 1.4. Which means when you put these on a camera, you're gonna end up with the same shutter speed and the same aperture. Now, the one for the full frame sensor will shoot with shallower depth of field and that depth of field is not in any sort of number. There is no number that goes along with the lenses to how shallow you can shoot. That's just gonna be an effect that you're going to see as a result of that 1.4 aperture. But because, the 1.4 lens is projecting its image on to a larger sensor, it is collecting more light, but the resulting shutter speed and angle of view is the same. When we talk about equivalence in comparisons between different sizes, there are some things that are the same and there are some things that are different. So these two lenses, there's three things that are important. Number one, they're exactly the same in the angle of view. Number two, they have exactly the same aperture. But the third thing is that they are gonna have a different depth of field between them. And so two of the three key factors are the same, but one of them is different. And there are some photographers that concentrate on the one that's different and so they'll argue, they're not the same, they're not the same. Well they're the same in two things, not the third thing. This is from Jean Ames who says, what is the difference between the sensors, of say a Canon 6D and say, which is considered to be an amateur full frame, versus the Canon 5D Mark IV, which might be considered to be a professional camera. So they're both full frame sensors, but what's the difference? Yeah, there are some cameras and it varies for manufacturer, I think I do have a 6D and I thought I had a 5D Mark IV, it might be in my bag. We'll just look at the 6D for right now. In that particular case, the difference is that 6D, and I'm trying to remember my numbers here, got a lot of numbers coming through my brain right now, and I'm thinking 26, is 26 megapixels, the 5D Mark IV which is the step up to this is 30 megapixels and yes that's four more for all of you that are good at math, but in reality, it's not that big a difference. It's a few hundred pixels on each side, and by the time you blow your images up, it's hard to see any difference at all. There are a number of manufacturers that have nearly identical sensors in different cameras, it's the features in the camera that are different. The other thing that's important is the processing of the information and generally, newer cameras have better faster processors and they can take information from a particular sensor and make it better than a previous camera. You really have to look at individual cameras, so in that case, I can tell you there's four megapixels difference, but when it comes to true final image quality, negligible. Almost no difference at all. You're gonna be looking at other feature differences that are important in that case. Alright, awesome. Everyone, as we started out by saying this course here is always going to be free, this camera buyer's guide, will always be free right here on this class page, at CreativeLive, however I highly encourage you, if you were enjoying the way that John talks and his knowledge about gear and cameras and photography, be sure to check out the rest of his classes here at CreativeLive, he is best known for his fundamentals of photography here at CreativeLive. He is also has his lenses courses. The photography starter kit for beginners is a shorter version of the fundamentals class, and of course he has fast start classes for probably most of the cameras that you might have out there. All you have to do is search Gringo on CreativeLive and that's when you'll see all the different classes that he has available right there and then.

Class Description

Buyer's guide will be your guide to figuring out the best digital camera for your needs.

Gear expert John Greengo dives into the major brands and lenses that are currently on the market.

John breaks down some of the more confusing aspects of mirrorless and DSLR's from focusing systems to sensor size; you'll get a better understanding of what the gear does so you can make an informed decision.

At the end of the class, John gives his recommendations for different types of photographers from the aspiring student to the filmmaker and everyone in between.


Samantha Locadia

John is a great teacher, and I've learned allot in this lesson. I already had an idea what camera I want to buy next but happy to know it was also what he recommended (for my field). Really love his free classes by the way where he talks with other photographers and discusses photos of viewers. Awesome!

Michael And Dawn

John has a very good way of explaining things to make them both simple and complete. His makes great use of visual graphics in his explanations. I highly recommend any of his courses, the material presented is well thought out and flows very well.

Kevin Li

Amazing course. So much education provided in these free classes. I will definately be taking more. I am so glad I watched these before jumping in and buying a camera. This is a much watch for all people who are new to photography and are looking to buy a camera.