Lesson Info
26. Aperture
Summary (Generated from Transcript)
The lesson is about the fundamentals of photography, specifically focusing on aperture. The instructor explains what aperture is and how it controls the amount of light entering the camera sensor. He also discusses the different names for aperture, such as diaphragm and iris. The instructor then goes on to explain the concept of focal stop and the ratio between the focal length and the entrance pupil of the lens. He provides a graphic for memorizing the different aperture settings and explains how changing the aperture affects the amount of light entering the camera. The instructor also clarifies the difference between maximum aperture and the range of aperture on zoom lenses. He encourages the students to memorize the aperture settings and provides a hint for doing so. The lesson concludes by mentioning that aperture not only controls the amount of light, but also affects the depth of field in photography.
Q&A:
What is aperture?
Aperture is the opening in the lens that controls the amount of light entering the camera sensor.
What are some other names for aperture?
Other names for aperture include diaphragm and iris.
What is the focal stop?
The focal stop is the ratio of the focal length to the entrance pupil of the lens.
How does changing the aperture affect the amount of light entering the camera?
Closing the aperture down lets in half as much light with each setting, while opening up the aperture lets in twice as much light.
What is the difference between maximum aperture and the range of aperture on zoom lenses?
The maximum aperture refers to the widest aperture that a lens can achieve, while the range of aperture on zoom lenses refers to the different aperture settings available at different focal lengths.
How can the aperture settings be memorized?
The aperture settings can be memorized by remembering the numbers 1 and 1.4, and doubling the previous number in the sequence.
What is the range of aperture settings commonly used in photography?
The range of aperture settings commonly used in photography is typically from 1.4 to f/22.
Does changing the aperture only control the amount of light entering the camera?
No, changing the aperture also affects the depth of field in photography.
Lessons
Class Introduction
23:32 2Photographic Characteristics
06:46 3Camera Types
03:03 4Viewing System
22:09 5Lens System
24:38 6Shutter System
12:56 7Shutter Speed Basics
10:16 8Shutter Speed Effects
31:57Camera & Lens Stabilization
11:06 10Quiz: Shutter Speeds
07:55 11Camera Settings Overview
16:12 12Drive Mode & Buffer
04:24 13Camera Settings - Details
10:21 14Sensor Size: Basics
18:26 15Sensor Sizes: Compared
24:52 16The Sensor - Pixels
22:49 17Sensor Size - ISO
26:59 18Focal Length
11:36 19Angle of View
31:29 20Practicing Angle of View
04:59 21Quiz: Focal Length
08:15 22Fisheye Lens
12:32 23Tilt & Shift Lens
20:37 24Subject Zone
13:16 25Lens Speed
09:03 26Aperture
08:25 27Depth of Field (DOF)
21:46 28Quiz: Apertures
08:22 29Lens Quality
07:06 30Light Meter Basics
09:04 31Histogram
11:48 32Quiz: Histogram
09:07 33Dynamic Range
07:25 34Exposure Modes
35:15 35Sunny 16 Rule
04:31 36Exposure Bracketing
08:08 37Exposure Values
20:01 38Quiz: Exposure
20:44 39Focusing Basics
13:08 40Auto Focus (AF)
24:39 41Focus Points
17:18 42Focus Tracking
19:26 43Focusing Q&A
06:40 44Manual Focus
07:14 45Digital Focus Assistance
07:35 46Shutter Speeds & Depth of Field (DOF)
05:18 47Quiz: Depth of Field
15:54 48DOF Preview & Focusing Screens
04:55 49Lens Sharpness
11:08 50Camera Movement
11:29 51Advanced Techniques
15:15 52Quiz: Hyperfocal Distance
07:14 53Auto Focus Calibration
05:15 54Focus Stacking
07:58 55Quiz: Focus Problems
18:54 56Camera Accessories
32:41 57Lens Accessories
29:24 58Lens Adaptors & Cleaning
13:14 59Macro
13:02 60Flash & Lighting
04:47 61Tripods
14:13 62Cases
06:07 63Being a Photographer
11:29 64Natural Light: Direct Sunlight
28:37 65Natural Light: Indirect Sunlight
15:57 66Natural Light: Mixed
04:20 67Twilight: Sunrise & Sunset Light
22:21 68Cloud & Color Pop: Sunrise & Sunset Light
06:40 69Silhouette & Starburst: Sunrise & Sunset Light
07:28 70Golden Hour: Sunrise & Sunset Light
07:52 71Quiz: Lighting
05:42 72Light Management
10:46 73Flash Fundamentals
12:06 74Speedlights
04:12 75Built-In & Add-On Flash
10:47 76Off-Camera Flash
25:48 77Off-Camera Flash For Portraits
15:36 78Advanced Flash Techniques
08:22 79Editing Assessments & Goals
08:57 80Editing Set-Up
06:59 81Importing Images
03:59 82Organizing Your Images
32:41 83Culling Images
13:57 84Categories of Development
30:59 85Adjusting Exposure
08:03 86Remove Distractions
04:02 87Cropping Your Images
09:53 88Composition Basics
26:36 89Point of View
28:56 90Angle of View
14:35 91Subject Placement
23:22 92Framing Your Shot
07:27 93Foreground & Background & Scale
03:51 94Rule of Odds
05:00 95Bad Composition
07:31 96Multi-Shot Techniques
19:08 97Pixel Shift, Time Lapse, Selective Cloning & Noise Reduction
12:24 98Human Vision vs The Camera
23:32 99Visual Perception
10:43 100Quiz: Visual Balance
14:05 101Visual Drama
16:45 102Elements of Design
09:24 103Texture & Negative Space
03:57 104Black & White & Color
10:33 105The Photographic Process
09:08 106Working the Shot
25:29 107What Makes a Great Photograph?
07:01Lesson Info
Aperture
Alright, it's time to move on to the aperture within the lens. And so, in your lens is an aperture that is gonna be able to give us some control over the amount of light coming into the sensor. So this is the opening through which light travels. Now I have found that the word aperture gets used in some incorrect ways much of the time. People will ask you, what aperture is that lens you have? And that's actually incorrect. What they're trying to ask you is, what's the maximum aperture of that lens you have? Because the maximum aperture is listed there. It's that 1.4 formula in this particular case. When they ask about the aperture, that is really the mechanical device in the lens that opens and closes, alright? Diaphragm, iris, it has a lot of different names that it can go by. And so, with this, the focal stop, the ratio of the focal length to the lens to the entrance pupil. So this is the size of the opening that we're shooting. And so this is a good graphic for you to memorize. Alrig...
ht, that's why we have it up on the wall in here right now. It's a very important concept to remember, because these are fractions and it's kind of awkward because 1.4, which is a small number, is a big opening. And 22 is a small opening but it's a big number relatively speaking. So let's go ahead and take our aperture and start closing it down. So as we close our aperture down, with each one of these settings we're letting in half as much light. So these are very important increments. And as we open up our aperture, we are letting in twice as much light. So it's very much like shutter speeds in that we're gonna be trading these numbers back and forth. Well, maybe I should do this with the shutter speed and this with the aperture and everything will be equal, just kind of trading them one for the other. And so 1.4 wide open, 22 very small. So if we go from 5.6 to f/ we are opening up the aperture by a full stop. We're letting in twice as much light. If we go from 5.6 to f/8, we're stopping it down and letting in half as much light. And this is where things are a little bit different than they were with shutter speeds and ISOs. If you remember back to shutter speeds and ISOs, we were doubling the numbers and we were cutting them in half. Not so here. In this case, we're going from 5.6 to f/4. And we double the amount of light, and that's because with a circle, that kinda has unusual properties. You only have to make a circle a little bit bigger to double the surface area of that. So that's why we have this kind of odd set of numbers that you need to know about in photography, and these are kind of the prime aperture numbers that you will see listed for lenses and settings on your camera. Now, some people with these zoom lenses we were talking about, with variable apertures, get a little confused because they go, I got this 16-80 lens, it has a range of 2.8 to f/4, does that mean I only get to use two apertures, 2.8 and f/4? Because it kind of sounds like 2.8-f/4, that's the range that you have. No, what that means is it means that 16 millimeters, you are gonna be able to have a maximum aperture of 2.8. Alright, but you'll be able to stop your lens down probably to f/22 or maybe beyond. When you zoom it out to 80, your maximum aperture is f/ and you'll be able to stop it down to 22, 32, or maybe beyond. And so it's just listing what the maximum aperture is. It's not listing the range of the aperture. So when you see that listed on your lens, it's just one part of the equation. But it's the important part of the equation. Usually we're not checking to see how far down our lenses can stop, although that can be a factor for some people who do need lots of depth of field. But generally lenses are gonna stop down more than enough for what everybody needs. It's the other end that's the really important end. Alright, this might be the least favorite slide in my entire class. I want you to memorize all the aperture settings. Does anyone feel now like they could just rattle off all the aperture settings? Raise your hand if you think you can just rattle off all the aperture settings. Nobody? Like, if I had to write down on a piece of paper, okay? Well, let me give you some hints on how to do it. If you can remember two numbers, you can figure out the whole sequence. The first number is number one. And that's so easy that doesn't take any effort at all. So you only need to remember the next number in the sequence, which is 1.4. Now the way that you figure out the whole formula is you take a number and you double it for the following number. And so if you're at a certain number, you just look to the previous number, you double it and that becomes your next number. So every other number doubles. Alright, you see the sequence here? So if you can remember 1 and 1.4, you could figure it out as far as you need to go. So let's go ahead and take this out a little bit further here. Do the math right as you've seen it on screen. What's the next number gonna be? Now yes, every once in a while, we do round a number up just for simplicity sake. And you can keep taking this on into infinity. So remember 1 and 1.4. And what's special about 1.4? It is the square root of 2. Okay, that's as far as we'll go into that. Alright. But this is the series, remember, 1 and 1.4. Now let's see who can answer this tricky question in the class. So, if we, well, there's actually a story about this. You've all heard of the movie director Stanley Kubrick, right? Well, he produced a movie called Barry Lyndon, and in Barry Lyndon he was filming some really really low-light scenes. And he needed the fastest lenses he could find. Now the fastest lenses he could find were special Zeiss lenses that were made I believe for the NASA program. Alright? And so he got his hands on one or two of these lenses so he could film this really low-light scene. And the lens that he got was one stop faster than a 1.0 lens. My question to somebody in the audience here is, what was the aperture of that lens? It's a stop faster than a 1.0 lens. If you know, raise your hand and we'll pass up. Let's get the microphone up here. It's half of 1.4. Okay, so what's half of 1.4? .7. Thank you. .7, alright. So everybody, check your closets, check your basements, your attics, see if you have a Carl Zeiss Planar 50-millimeter f/0.7 lens, and it's gonna be worth a mint, alright. There's only like six of these things made. And so, yes, you can have lenses faster than 1.0. It just happens to be a relation of a 50.1.0 lens is a 50-millimeter lens with a 50-millimeter opening. With this, I'd have to run the math, but it's gonna be 60-some millimeters in its opening. And so it's a difficult, challenging lens to make. But it is possible, so you can go to really almost infinity in either direction on this, as far as you want. So just remember, 1 and 1. and you've got them all memorized. Now how many people in this audience can figure out all the apertures? Raise your hand. Okay, I was hoping to see everyone's hand. Good. (laughter) 'Cause it's really easy once you know the secret formula. Alright, so the apertures you're gonna be using in the real world of photography, for the most part, are gonna range from 1.4 to f/22. Now like shutter speeds and the ISOs, we're gonna be able to select third stops if we want. So if you wanna get very precise or you need just a little bit more depth of field or you're trying to balance some other part of the equation, feel free to set these thirds of stops. There's no problem with them. I'm just not gonna list them 'cause they clutter up my screen with too many numbers. We're gonna stick with the whole numbers. So, these apertures are gonna control the amount of light coming through the lens. But they do something else that is quite interesting and makes photography a lot of fun. And that is it controls the depth of field, and this is what we're gonna talk about in the next section.
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a Creativelive Student
Love love all John Greengo classes! Wish to have had him decades ago with this info, but no internet then!! John is the greatest photography teacher I have seen out there, and I watch a lot of Creative Live classes and folks on YouTube too. John is so detailed and there are a ton of ah ha moments for me and I know lots of others. I think I own 4 John Greengo classes so far and want to add this one and Travel Photography!! I just drop everything to watch John on Creative Live. I wish sometime soon he would teach a Lightroom class and his knowledge on photography post editing.!!! That would probably take a LOT OF TIME but I know John would explain it soooooo good, like he does all his Photography classes!! Thank you Creative Live for having such a wonderful instructor with John Greengo!! Make more classes John, for just love them and soak it up! There is soooo much to learn and sometimes just so overwhelming. Is there anyway you might do a Motivation class!!?? Like do this button for this day, and try this technique for a week, or post this subject for this week, etc. Motivation and inspiration, and playing around with what you teach, needed so much and would be so fun.!! Just saying??? Awaiting gadgets class now, while waiting for lunch break to be over. All the filters and gadgets, oh my. Thank you thank you for all you teach John, You are truly a wonderful wonderful instructor and I would highly recommend folks listening and buying your classes.
Eve
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JUAN SOL
Dear John, thanks for this outstanding classes. You are not only a great photographer and instructor, but your classes are pleasant, they are not boring, with a good sense of humor, they go straight to the point and have a good time listening to you. Please, keep teaching what you like most, and I will continue to look for your classes. And thanks for using a plain English, that it's important for people who has another language as native language. Thanks again, Juan
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