Hi today we'll show you how an SLR camera works. This is an older Olympus O30 a film camera but the same applies to digital SLR cameras as well. This is the lens mount here, this ring, and you screw a lens onto there. And basically what happens is, it's very simple. The light comes into the lens, don't worry I'm not poking the mirror, in through there, through the lens. This is normal upright, this is the fore the shutter button is pressed, the light comes in, there's a mirror here, this is called the mirror box, there's the area here, the light reflects off the mirror up onto a part for the focusing screen, which is a bit like a projector screen, in fact it is like a projector screen. And if I show you from the back, right now, you can see the focusing screen through there. Anyway, I don't have to confuse you, so basically yeah, the light comes in front of the camera like that. Bound is off the mirror, which is at 45 degrees, up here, the focusing screen. And then that image is reflected inside a prism here called the pentaprison. And that focused image is come out comes out through the viewfinder, which is what you see. You won't see anything now because there's no lens attached, so it's not focused. So again, so yeah, the light comes in here, bounces off the mirror, which is 45 degrees, up onto the focusing screen where it's focused, when you focus the lens, you'll focus it on the focusing screen. And then that image is then reflected through the prism to your eye, which is obviously at the back on the viewfinder. Now, that mirror is down at 45 degrees all the time, apart from when the mirror is open, is lifted up to take the photo. Press the shutter button here, the mirror goes up, and it exposes the film. But since it's finished, the exposure, the mirror drops back down and you continue to see the image through the viewfinder again. So I set that for a one second exposure, so that's why that's why I went on for a second. That's why the mirror lifted up for a second, so you get a good look. So let me start from beginning. Press the shutter button, mirror goes up, the film's exposed, the mirror drops down. So let me put on a faster shutter speed, the moment it's on one second, this is a camera very kindly donated to me by friend. So let's put on a thousand to a second, one thousandths of a second. Can't speak properly today. One thousandths, thousandths, sorry. So press shutter, very quick exposure, that's one thousandths of a second. Again, you see the mirror flip up out of the way. The shutter opens, the light hits the film or the sensor. The shutter shuts, mirror flips back down again, I think in that order. That's how I've just taken very simple indeed. So there you go. This is a lovely old camera, Olympus OM30, donated to me by my friend Justin, for a kind look. One more time for prosperity. Get the strap out of the way. There, if that explodes you're down to one second. You've got the torch in there, so you can see. Ready, set. That one more time, so you can see the film area. Flash on the torch in there. There you go. Bye-bye.