Aperture
Tomas George
Lesson Info
8. Aperture
Lessons
Introduction and What You're Going to Learn
00:29 2Video Resolutions
04:15 3Frame Rates
07:25 4Aspect Ratios
02:40 5The Rule of Thirds
01:19 6The Exposure Triangle Introduction and Light Meter
01:18 7Shutter Speed for Video
03:04 8Aperture
05:22ISO
06:35 10PAL Region Downloadable Guide/Cheatsheet
02:04 11NTSC Region Downloadable Guide/Cheatsheet
02:36 12White Balance
03:51 13Different Types of Camera Lenses
05:17 14Focal Lengths
01:15 15Thread Sizes and Lens Mounts
01:22 16ND Filters
04:52 17Polarising Filters
00:53 18UV Filters
00:58 19DSLR vs Mirrorless Cameras
04:01 20Talking Head Video Setup Walkthrough
12:18 21Outside Higher FPS Video Walkthrough
12:18 22Thanks and Bye
00:11Lesson Info
Aperture
Hi there and welcome to this video where I'm going to be talking about the next part of the exposure triangle which is aperture. So aperture allows us to control how much light enters our camera and also allows us to control the depth of field of our shot or how blurry we have the background of the shot. Adjusting the aperture allows us to adjust the hole in the lens. This is where the light travels in and hits the sensor of our camera. So aperture basically affects how much light hits the sensor of the camera. Cameras are designed like the human eye in the eye. We have the iris which controls the size of the pupil from shrinking and expanding the aperture is essentially the pupil, the larger the pupil, the more light will fall onto the retina and the larger the aperture of the lens, the more light that will enter the camera in videography and photography aperture is measured in F stops F stops describe how open or closed the aperture is. The smaller the F stop number, the wider the ap...
erture and the more light will get let into the lens and into the camera, the larger the F stop number, the smaller the aperture and less light will get let into the lens and into the camera. For example, F 1.8 will have a larger aperture than F 11 and F 1.8 will let in more light than F 11. The aperture also affects the depth of field for your image. This is the area for image that's in focus a narrow or shallow depth of field means you have a small area of your image and focus a wide depth of field means you have a large area for image and focus. So a large aperture or small F stop number such as F 1.8 will have a small area of the image and focus and will have the foreground and background out of focus. This could be useful for isolating the subject or for getting a blurry background effect. Also, if you want to get a blurry background effect, the subject will need to be far from the background and you'll need to use a low F stock number. However many kit lenses which the lenses that come with the camera may only have a maximum aperture of F 3.5 for example, and this really isn't enough to get that blurry background effect. Most of the time, it's also normally the more expensive lenses that open up to a wider aperture such as F 1.81 0.4 or 1.2. So something between A F 1.2 to 2.8 could be used to isolate the subject and to get that blurry background effect for this shot you're looking at right now, I'm using a F 1. any more than this, say F 1.4 or F 1.2. There may not be enough of my face and focus. For example, it may put my ears out of focus when the camera focuses on my eyes. As F 1.2 or F 1.4 does give very shallow depth of field for a talking head video like this. I do recommend around F 1.8 if you want to get a narrow depth of field but still have the facial features and focus for many years. Though I did use a lens that had a maximum aperture of F 2.8 which was fine also, but the background wasn't quite as blurry. I also needed to properly expose my image with more light or a higher iso number as using a low F stock number like F 1.8 or let in more light to the camera than say F 2.8 which means if you're using a high F stock number or a low aperture, then you may need more light in the room or you may need to apply more iso to properly expose the image iso is digital light and with higher amounts, it can introduce noise or grain to a image. So generally you want to use a low iso number. However, I will be talking about iso in detail after these aperture videos. Also just be aware that you don't always need to use a low F dot number to get a good shot. You may wish to decrease your aperture or use a high F stop number. If you want to get more of your background and focus, this could be useful if you have multiple people in the shot in different places, or if you're filming landscapes where you want a wide depth of field for your shot, even for sports. For example, if there are multiple people in the shot that are not standing next to each other and you want to get them in focus, you may wish to use a high F stop number or a lower aperture. For example, we could decrease the aperture to say F- to get more of the background and focus as we use a lower stop number, you'll notice the background becomes less in focus. So if you want the background to be in focus, I recommend using a smaller aperture or a higher F stop number such as F-22 to get a wider depth of field. OK. So now let's have a look at an example here, I'm shooting with the ISO in auto so I can quickly change the aperture and it will properly expose the image. Also the shutter speed is at 1/ because I'm shooting at 25 frames per second. And we want to have the shutter speed at double the frames per second number. Also. Right now, the F stop number is F 5.6. And you can see some of the background in the distance. It's not completely in focus, but we can still see it's there. So let's now increase the aperture to F 2.8. And you can see it really blurs the background that isolates the subject. Even at 2.8 we still get a really blurry background because the subject is far away from the background. Let's now increase the aperture to F 1.8 which is the lowest F stop number for this lens. And you can see here it really blurs the background with this high aperture setting. Let's now decrease the aperture to a much smaller aperture. Let's choose F-22. And you can see now a lot more the backgrounds and focus. So if you're going to be near the background, it may be difficult to get that blurry background effect. Even if you open up the aperture wide, as I said before, if you want that blurry background effect, I recommend having the subject far away from the background. So if you're going to be shooting indoors and you're in a small room and you want that blurry background effect, I recommend using a lens that opens up wide, maybe around F 1.8. However, if you're outside or somewhere like this, where the subject is far away from the background, you can blur the background out with an aperture like this, which is F 2.8. OK. So that's aperture and it allows you to affect how much light hits the sense of your camera and also the depth of field for your image. Thanks for watching and I'll see you in the next one.
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