Alright this next section, called photo basics, is for anyone who is kind of new to SLR photography or new to manually controlling shutter speeds and apertures. I just want to go through a quick review of what an SLR is, it's sensor size and so forth, just to make sure that everybody's talking on the same playing field you might say. So this is a single lens reflex camera, which means we have a single lens, obviously. There's lots of different lenses that you can choose from, wide angle, telephoto and we'll talk a little bit more about those lenses later on in the class. In every lens is an aperture unit that can open and close down. It never completely shuts down but it does has different sizes and different f/stop settings as we get to know them in photography. And so we can open up the aperture to let in more light, we can stop down the aperture to let in less light. So this is a great way of controlling the amount of light getting into the sensor on the camera. Beyond just controll...
ing the amount of light, it also controls the depth of field or how much will be in focus from foreground to background and so if you have a lens that goes down to 1.4, you're gonna get very shallow depth of field. With those things close to you and very far away from you potentially out of focus depending on where you focus at. Now as you stop your aperture down, the depth of field grows, you get more and more in focus. When you stop all the way down to f/ like a lot of lenses have, you're likely to have great depth of field. Now there's a number things that are involved in this and we don't have time to go into all of it. That's more for a general photography class but that's the real basics on what's happening when you are changing the aperture. As light enters into the camera, we get to the reflex portion in SLR. The mirror, any device that has a mirror is often considered a reflex device. It bounces the light upward to the focusing screen, which you can see when you look through the view finder and the light bounces through the prism system so you can see exactly what the lens sees. And this is great because you get to see the angle of view, you get to see whether it's in focus, you get to see whether you left the lens cap on your camera and so it's a very valuable tool and it's why it's been a favorite among photographers for many, many years. Now in order to shoot a photo, we press down on the shutter release, the mirror needs to get out of the way so that light can get back to the image sensor. Before it can make its way all the way back to the image sensor, it needs to get past the shutter unit which has two parts, a first curtain and a second curtain. So the first curtain will slide open and we can see it from the front and from the side here. It's gonna slide open, this is our exposure and then the second curtain is gonna come down and block the light off and then the mirror comes back down so that you can see what's going on to frame up your next shot and then the shutter unit will return to its starting position and it does this every time you take a photo. Now shutter speeds are used for controlling the amount of light coming in to the sensor and it's also used for controlling motion. You can stop motion, you can blur motion depending on whether you're choosing a fast shutter speed or a slow shutter speed. One of the most important factors in any camera is the sensor and the size of the sensor is very important, that determines what sort of lenses will work with it and the quality of photos that you will get from it. The 77d uses what I would consider to be a medium sized sensor. It's one of the most popular sensors for serious photographers out there in the market. It is a little bit smaller than the traditional 35mm film. There's a lot of cameras out there that do have these, what are known as full frame sensors and this is a little bit smaller, allows the camera to be a little bit smaller and cost a little bit less money. It uses a 1.6 crop factor and so when you're talking about what focal length you see, there's a little bit of a crop factor to figure in if somebody is talking about something in full frame and how that lens will respond when you have it on this camera or a camera with a sensor this size. For holding the camera, one of the things you want to do is obviously put the camera in your right hand and grab the grip of the camera but in the left hand, you want to cradle the lens in your hand so that your thumb is pointing upwards. That is gonna be a more stable position because it gets your elbow into a more stable position next to your torso and you'll be able to hold the camera steadier under low light conditions which can be very helpful. Through out this class we're gonna be talking about a lot of different features that could be controlled automatically or manually. And so sometimes the difference between auto and manual is do you have the time to set it up, do you want to put out the effort to go in and make those sorts of changes and do you know what you're doing on all these? And so while it is fine to put this camera in a fully automatic mode, you are likely to get good basic photographs of almost everything you point the camera at, it's really nice to be able to know how to do it manually. That way if you want to get consistent results or you know what the camera doesn't understand about a situation, you can go in and do it yourself. So that's what we're gonna be concentrating on in this class. So if you want to know more about basic photography, as I said before, the two classes that I have, either a short one or a long one, they are available here at Creative Live and these will take you through shutter speeds, apertures, depth field, lighting, composition and all those other important elements beyond just the operation of your camera that are very important for taking good quality photos and so I encourage you to take a look at one or both of those classes.