The Sensor


The Photography Starter Kit for Beginners


Lesson Info

The Sensor

All right, let's dive into the next section. We're gonna talk about the sensor in the camera. In the old days, we would've been talking about different films, we would've been talking about Kodak, Fuji, Agfa, and all the other ones, but let's talk about the sensor. Inside your camera, if you were to take off a lens, and if you had a mirror, get that out of the way, and the shutter unit out of the way, is the sensor, the light recording device in your camera. There's a lot of different things going on here that you need to be aware of when choosing a camera and using a camera. First off, there are lots of cameras. Yes, there are lots of cameras out on the market. And they have different size sensors in them, which is going to allow different types of accessories to be used with them, and really kind of be the sole determinant or the big factor that controls how good they are at doing a variety of different things. Now, the fact of the matter is, is not that many people shoot 35 millimet...

er film anymore, but a lot of people did. It was the most popular film format for many, many, many years, because it was the Goldilocks of film. It was small enough that we can put it in a camera, hang it around our neck, and trudge around Europe for two weeks, all right? It wasn't too bad for that. But it was also big enough that we could make a decent-sized poster, and it was just that perfect size. And so, when we made that transition many years ago, from film to digital, it was really convenient for all of us photographers who had film cameras just to buy a new digital camera and use it with our collection of lenses. And so, despite the fact that not that many people are shooting 35 millimeter film anymore, that's still the gold standard when it comes to sensor size. So that's what we call a full-frame sensor. In order to make more affordable cameras and smaller cameras, the manufacturers worked on smaller-sized sensors. A lot of the Canon and Nikon entry-, medium-level cameras are using an APS-C system, slightly different sizes between them, but they're both roughly the same. The micro Four Thirds system is using a little bit smaller-sized sensor; and then there is some smaller sizes, and they will give you these very unusual fraction sizes, which is an indication of the sensor size. We're not gonna get into it, but I will tell you that these numbers are highly deceptive. 13 by 9 millimeters is nowhere close to an inch in size. It's called inch by name only: it's not really an inch in size, which is very deceptive. The small ones, the whole thing is very confusing. I wish we would throw the entire thing out the window, because the naming protocol system for sensors is complete garbage. I've kind of taken my liberty of going in and I'm gonna rename 'em. I think it's a lot easier if we name them the same way we do our TVs and our monitors: just measure it from corner to corner and give me a number. A full-frame camera is 43 millimeters across diagonally. The smaller camera's around 27, 28; Four Thirds is 22, and so on and so forth. Your typical iPhone is around 6 millimeters in the size of that sensor, and as far as comparing them, I think this makes a lot more sense in how you compare them. All right. The ones we're going to look at a little bit more closely, the ones where you have a lot of interchangeable lenses, are on these four sizes right here. So Canons, Nikons, Sony, Pentex, all make cameras that are full-frame cameras. Exactly the same size as 35 millimeter. Now, Fuji, Leica, Nikon, Pentax and Sony make a 1.5 crop; and very, very close to that is the Canon one. Why do we call this a 1.5 crop? Basically, it's the relationship of 28 millimeters to 43 millimeters; and we can figure out that in a couple different mathematical ways. We're gonna talk more about this cropping aspect, but it's smaller, and it crops the frame around the edges, 'cause it's a smaller-sized sensor. Canon's is a little bit smaller at 1.6, and then the Four Thirds' is roughly a two-times crop factor compared to 35 millimeter. The sensor size is important because the imaging area is gonna control how many pixels we have, and certain capabilities of the camera. For right now, in general, the bigger is better, 'cause a bigger surface area for gathering more light. Let's take a look at a scenario where we are shooting with a full frame sensor, so we're gonna use the entire area, and we're gonna capture an image. All right, so here's our image. Now how does it differ working with a full frame camera versus a crop frame camera? Well, if we were to take the exact same setup and use a crop frame camera, it's using a smaller-sized sensor, which records a little bit smaller area. Now is that the same image as what you just saw a second ago? Well, it's the same scene, but it's a different angle of view. We're not getting this area around the edge, and so the angle of view is different, and so it's not really giving you the exact same photo. It's a cropped-in image, cropped by a factor of 1.6. This image was taken with a full frame camera, 43 millimeter sensor on it, with a wide angle 16 millimeter lens. If I wanted to get that exact same image with a crop frame sensor, I certainly can: and I can do it with a 10 millimeter lens. Now why a 10 and not a 16? All right, well, I apologize. There's a little bit of math involved in photography. 10 millimeters times the crop factor, 1.6, gets us back to 16: so these are equivalent lenses for the sensors that they have. If you tell me about a shot that you're trying to get, and you tell me what lens you're using, and you wanna know if that's the right thing to use, I'm lost: I have no idea what to say, because I don't know what sensor you're using yet. I need to know the sensor and the lens: they work together, and so you have to know, if you know one, you gotta know what you're doing with the other one. This was a problem in the early days of digital, 'cause there wasn't really all these good wide-angle lenses. It was great for telephoto, all right? Now, we're out shooting wildlife. Got a humpback whale jumpin' out of the water. We got a full frame camera. Now what would happen if we shot this with a crop frame camera? All right, now our pixels are a little bit more concentrated on our subject: we're not getting all that extra area around the edge. So if you're into sports and wildlife photography, there is an advantage to a crop frame camera, because you don't need as big a lens to get in and get that shot. So if you were taking this picture on a crop frame camera you would probably need something like a 300 millimeter lens which is a pretty big lens, and it's not cheap, but it's something that you could, most people could probably put in the budget and get it after a little bit of time. Now, as we talk more and more about sensors, you're gonna probably say "Whoo, I should upgrade "from my crop frame sensor to a full frame sensor, "'cause those are better cameras, right?" Yeah, they are better cameras, in general. But if you wanted to get this exact same shot with a full frame camera, let's figure off what lens we're gonna need, because lenses are matched to their sensors. We started with a 300, but we were on a 1.6 crop, which is the equivalent of 480: let's just call it 500. So you're gonna need a 500 millimeter lens, which is twice the length, three times the weight, and about six times the price. So if you wanna upgrade, go for it: it's great. It's gonna cost ya, in everything. The camera costs more, the lenses cost more. This was one of the big problems that I saw back in the days of digital, when full frame cameras first started becoming more popular, is that people would say "Oh, okay, "I can afford a full frame camera. "I'm gonna go buy a full frame camera. "Well, I can't afford the lenses, "so I'll just use my old lenses." Then they weren't getting the image quality that they expected; and when you upgrade one, you gotta bring the whole system up, because it's a matter of lens quality and sensor quality that works together. So if you wanna go full frame, that's great: just buy lenses that are appropriate for doing that. In summary, we have different size sensors. In general, you will get better performance from the larger size sensors; but there is a price to be paid, a literal price to be paid. And it's also in size and weight. So, as an example here, I have a full frame camera, I have a 1.5 crop, and I have a micro Four Thirds two times crop camera. I can find use for all of these. This is really nice if you're gonna be going to work or school, and you just kinda want one little camera to throw in the camera bag that still has a lot of good manual controls that still has the ability to take the lens on and off, and, you know, feels good in the hand. This is a camera that I like to work with. It's small, it's light, the lenses are relatively small and lightweight to work with. When things get really serious, it's nice to have a nice big grip on this camera: it doesn't fall out, all the buttons are nice and big and easy to have, and so there's a place and purpose for all of these different cameras. Which one is best? It really depends on what you're doing and what your needs are. If you're trying to compete with the highest level of professionals out on the market, whatever those other professionals that you're competing with is probably what you're gonna need to use, or something better. If this is for yourself, the best camera is the one that's with you, and so if you like the concept of this but (scoffs) you're just not gonna bring it with you, it's no good. Really, the best advice I've ever heard on what camera you should get is you should get the camera you are most happy using. Whatever that is, whatever you can afford, whatever camera you just say "God, I love this camera! "I always wanna take it with me." That is the best camera for you. Even if there's something else technically better, if you love this camera, that's the one you get. A Michelle Mealing had asked, "Does that mean that the equivalent crop frame cameras "have more distortion on the edges "when you're talking about the difference "and the different angle view?" Right, interesting thought there, but no. There is not more distortion. That is gonna be pretty much a sole contributing factor of the lens, how much warping or bending those lenses might have. That will be a topic that we might touch on real briefly in the lens section: but no, sensor size is not gonna play a part in that. Great, so it's the lens. Right. Another question that had come in from Gordon: "What is the largest sensor in a mirrorless camera?" My mind always starts thinking up, 'cause I'm always looking for wiggle room. "What do you really mean by a mirrorless camera?" Conventionally, it would probably be either the Sony or the Leica, which uses a full frame sensor: but, now that I just thought of that, I just realized that we've had a couple introductions in the last few months. Hasselblad and Fuji have introduced medium format cameras. I don't know that you can walk down to the store and buy one today, 'cause they're still kinda en route to the market, and they have a medium format sensor, and I'm forgetting the exact dimension; but if you remember, 43 millimeters, their sensor size is roughly 63 millimeters. It's another 20 millimeters, it's almost another inch in size. But, you know, I have a flatbed scanner at home, and technically, it's an imaging device. It doesn't have a mirror in it, and so I can photograph things with a scanner; and there are ScanBacks, which are technically mirrorless. Look for the Hasselblad or the new Fuji. Both of them look like very interesting new medium format mirrorless cameras. Studio? All right, we have another one online. "Full frame versus crop: could you not just back up?" Can you talk a little bit about, is there more difference with full frame-- Let me answer that question right here. Great. Okay, can I back up? Not always. Sometimes you can, and that is a solution. But sometimes, you're in a small room, and you're at the Grand Canyon: and if you back up, you can't see the Grand Canyon anymore. Backing up is a great option whenever it is an option. In theory, yes you can, to solve those problems, but that's not always a reality of this world. Thank you. And let's see, anyone's further? Nope, thought you were raising your hand. We have one more-- We have one question over here. Oh, great. Let's get a microphone up to the front row. When is the change in quality between sensors noticeable? You said that the full frame has a better quality than the smaller ones. When is that noticeable? The quality that you get from any particular sensor is dependent on a couple of things. One is the size of the sensor. That's, I don't know, it's kinda like the overall horsepower. But how it actually performs, it doesn't mean that two cameras with the same size sensor will perform the same. There are some cameras that, we use the term "punch above their weight level:" they do really well. For instance, can I admit that I'm a fanboy of, I really like Fujis, all right? They do a really good job on a number of things, and so this 24 megapixel sensor looks really good, and competes very well. This is a 30 megapixel sensor, and they're gonna look pretty similar. But if you were to go same, same in full frame versus crop frame, it's gonna be a little bit better when you start shooting in high ISOs. If you're shooting at ISO 100, a landscape-type scene, you're gonna see next to no difference at all. But when you start going and doing a concert, and you're shooting at ISO 6400, that full frame is gonna look a little bit better. In general terms, that's when we get to talk about ISO, it'll be about one stop better. If you have a full frame camera, it usually allows you to shoot at an ISO level one stop higher than you would with a lower-level crop frame camera. From Matthew Keiter, who says "What is the limit to sensor size "of wanting to enlarge the photo onto a big canvas?" So when it comes to printing, what are those factors, and does sensor matter? Sensor size is indirectly related to print size. Print size, at least from a theoretical point of view, has to do more with the number of pixels. In theory, in a perfect world, we could have a little tiny sensor, like a micro Four Thirds sensor, that has, oh let's just come up with a number. A trillion pixels. We could print a huge picture from it. But the reality is that, it does relate to the sensor size. For most people right now, you're gonna be able to print a 16 by 20, 20 by 24, quite nicely; and with the right printing setup, you can print two-, three-, four-foot photos. Many of us probably saw the iPhone campaign. I don't know if it was for the current or the previous one, where they had three-foot by four-foot posters shot with an iPhone, which I think at the time was around 10 megapixels or so. It's a matter of the lens and the processing and a lot of things, and so it's not a direct answer to that question, and I apologize for that. But that's the reality of the world. It gets a little complicated.

Class Description

“This is a great starter class. I thought I understood how shutter speed and aperture worked together, but this class made it come together in a matter of minutes. I'm already taking better pictures and this is just the beginning!” -Jennifer Manley, CreativeLive Student

Learn how to take the kind of photograph you’ll want to print and pass on to the next generation. John Greengo is back to teach this updated photography for beginners class. You’ll learn the principles of good beginner and intermediate photography and get the skills necessary to create amazing photos. 

Advanced cameras are available at modest price points, but learning how to use them takes an investment.

  • Learn the the most essential functions of your camera 
  • Gain confidence in putting new functions into action 
  • Get the swing of basic photographic terminology 
  • Feel prepared to move on to more advanced classes 
  • Gain a solid understanding of must-know lighting and composition techniques 
  • Lean to position yourself and your subject to capture the best photo possible with the camera you have – no additional gear needed 
If you want to take more memorable and inspiring photographs of your travels, your friends and family, or the great outdoors then this photography for beginners class is for you. Learn how to make average pictures amazing photographs and gain the ground necessary to continue your photography education.  

“This is a super introduction to photography for anyone who really wants to learn how to understand and begin to use the camera to its full extent. John is an excellent teacher, very easy to follow, with great graphics and examples.”  -Sarah, CreativeLive Student  


Kanoelani Patenaude

I am a pro photographer in my dreams, where I know the in's and out's of my camera; however, reality proved differently, as real life would tell you, I was a deer caught in headlights just looking at my new 7D Mark II. I am a photographer enthusiast without the skills, but a lot of love for the moments one, or the profession/hobby of it can capture. I mostly shoot my husband, friends, and community surfers in the lineup, and of course, my children, who rarely sit still. Thus, I switched from Nikon to Canon, venturing on the 7D Mark II for the grand reviews of how stellar of camera it is for action shots (surfing, and kids, this was a no brainer). That said, and overwhelmed with the way beyond my skill set, but noted desire and aspiration to grow, I made the purchase, and sought help rather quickly as I wanted to feel confident with what I was utilizing to capture the best memories possible. I came into this John's courses knowing the "on/off" button, and "auto" shoot mode. I came out of the course feeling like the pro in my dreams, and ready to shoot manual. John's teaching style is on point, and his detailed visuals are a huge plus. My first shots post this photography kit course, I thought were great for my first educated shoot, and shockingly, I even received and email from one of the sponsors of the surfers I captured, asking if they could use my image for their sites and publications. Not bad for a newbie. Though, my intent was never a business purpose, I did not know if I should charge a small fee, or give it for free. I don't mind free as it's not my business, yet I don't want to ruin it for any professional photographers in town doing the same thing that are charging. Perhaps another course to help me with that. I highly recommend courses by John Greengo! Thank you so much, John!

Megan Wagner

John is extremely articulate and is a great teacher with lots of visual aids and metaphors to help understand photography. I have been doing photography for a few years now and this class was a tremendous help in boosting my knowledge and refreshing my memory in multiple aspects of photography. The graphics that John uses are helpful and he even goes through images and asks which settings would be best to use and will go through the why. He makes things easy to understand and is very clear about the information he provides. I am so glad I took this course and I would highly recommend it even to an experienced photographer. Thank you John Greengo!