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Auto Focus Calibration

Lesson 53 from: Fundamentals of Photography

John Greengo

Auto Focus Calibration

Lesson 53 from: Fundamentals of Photography

John Greengo

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Lesson Info

53. Auto Focus Calibration

Summary (Generated from Transcript)

This lesson focuses on the topic of Auto Focus Calibration in photography. The instructor explains that DSLR cameras have a phase detection focusing system that can have slight errors, causing the focus to be inconsistent. The lesson teaches how to calibrate the camera to correct for these errors, using a focusing target and measuring if the focus is in front or behind the subject. The instructor also mentions that this calibration is especially important for those using longer telephoto lenses and fast lenses with shallow depth of field.

Q&A:

  1. What is Auto Focus Calibration?

    Auto Focus Calibration is the process of adjusting the focus of a DSLR camera to correct for any errors or inconsistencies.

  2. Why is Auto Focus Calibration important?

    Auto Focus Calibration is important because it ensures that the camera focuses accurately on the subject, especially when using longer telephoto lenses and fast lenses with shallow depth of field.

  3. How can you test if your camera needs Auto Focus Calibration?

    You can test if your camera needs Auto Focus Calibration by focusing on a subject and measuring if the focus is in front or behind the subject using a focusing target or a homemade test chart.

  4. How do you perform Auto Focus Calibration?

    To perform Auto Focus Calibration, you need to unfocus the lens, let it auto focus, and then take a picture. You may also take multiple pictures at each setting and unfocus in the other direction to achieve focus from both sides.

  5. Who would benefit the most from Auto Focus Calibration?

    Those using fast lenses with apertures of 2.8 or faster, including telephoto lenses, macro lenses, and portrait lenses, would benefit the most from Auto Focus Calibration.

Next Lesson: Focus Stacking

Lessons

Class Trailer
1

Class Introduction

23:32
2

Photographic Characteristics

06:46
3

Camera Types

03:03
4

Viewing System

22:09
5

Lens System

24:38
6

Shutter System

12:56
7

Shutter Speed Basics

10:16
8

Shutter Speed Effects

31:57
9

Camera & Lens Stabilization

11:06
10

Quiz: Shutter Speeds

07:55
11

Camera Settings Overview

16:12
12

Drive Mode & Buffer

04:24
13

Camera Settings - Details

10:21
14

Sensor Size: Basics

18:26
15

Sensor Sizes: Compared

24:52
16

The Sensor - Pixels

22:49
17

Sensor Size - ISO

26:59
18

Focal Length

11:36
19

Angle of View

31:29
20

Practicing Angle of View

04:59
21

Quiz: Focal Length

08:15
22

Fisheye Lens

12:32
23

Tilt & Shift Lens

20:37
24

Subject Zone

13:16
25

Lens Speed

09:03
26

Aperture

08:25
27

Depth of Field (DOF)

21:46
28

Quiz: Apertures

08:22
29

Lens Quality

07:06
30

Light Meter Basics

09:04
31

Histogram

11:48
32

Quiz: Histogram

09:07
33

Dynamic Range

07:25
34

Exposure Modes

35:15
35

Sunny 16 Rule

04:31
36

Exposure Bracketing

08:08
37

Exposure Values

20:01
38

Quiz: Exposure

20:44
39

Focusing Basics

13:08
40

Auto Focus (AF)

24:39
41

Focus Points

17:18
42

Focus Tracking

19:26
43

Focusing Q&A

06:40
44

Manual Focus

07:14
45

Digital Focus Assistance

07:35
46

Shutter Speeds & Depth of Field (DOF)

05:18
47

Quiz: Depth of Field

15:54
48

DOF Preview & Focusing Screens

04:55
49

Lens Sharpness

11:08
50

Camera Movement

11:29
51

Advanced Techniques

15:15
52

Quiz: Hyperfocal Distance

07:14
53

Auto Focus Calibration

05:15
54

Focus Stacking

07:58
55

Quiz: Focus Problems

18:54
56

Camera Accessories

32:41
57

Lens Accessories

29:24
58

Lens Adaptors & Cleaning

13:14
59

Macro

13:02
60

Flash & Lighting

04:47
61

Tripods

14:13
62

Cases

06:07
63

Being a Photographer

11:29
64

Natural Light: Direct Sunlight

28:37
65

Natural Light: Indirect Sunlight

15:57
66

Natural Light: Mixed

04:20
67

Twilight: Sunrise & Sunset Light

22:21
68

Cloud & Color Pop: Sunrise & Sunset Light

06:40
69

Silhouette & Starburst: Sunrise & Sunset Light

07:28
70

Golden Hour: Sunrise & Sunset Light

07:52
71

Quiz: Lighting

05:42
72

Light Management

10:46
73

Flash Fundamentals

12:06
74

Speedlights

04:12
75

Built-In & Add-On Flash

10:47
76

Off-Camera Flash

25:48
77

Off-Camera Flash For Portraits

15:36
78

Advanced Flash Techniques

08:22
79

Editing Assessments & Goals

08:57
80

Editing Set-Up

06:59
81

Importing Images

03:59
82

Organizing Your Images

32:41
83

Culling Images

13:57
84

Categories of Development

30:59
85

Adjusting Exposure

08:03
86

Remove Distractions

04:02
87

Cropping Your Images

09:53
88

Composition Basics

26:36
89

Point of View

28:56
90

Angle of View

14:35
91

Subject Placement

23:22
92

Framing Your Shot

07:27
93

Foreground & Background & Scale

03:51
94

Rule of Odds

05:00
95

Bad Composition

07:31
96

Multi-Shot Techniques

19:08
97

Pixel Shift, Time Lapse, Selective Cloning & Noise Reduction

12:24
98

Human Vision vs The Camera

23:32
99

Visual Perception

10:43
100

Quiz: Visual Balance

14:05
101

Visual Drama

16:45
102

Elements of Design

09:24
103

Texture & Negative Space

03:57
104

Black & White & Color

10:33
105

The Photographic Process

09:08
106

Working the Shot

25:29
107

What Makes a Great Photograph?

07:01

Lesson Info

Auto Focus Calibration

The next little bit is exclusively for some special people, Nikon and Canon owners, Pentax, too. Anybody who uses a DSLR has a phase detection focusing system in their camera and I told you about the slight error that can happen and this is how you correct for that error. And, cameras are supposed to focus on a subject and be perfectly on. With mirrorless cameras, because they're grabbing the information from the sensor, it's actually accurate all the time. And so, it knows when it's got it. But, for an SLR, it's an estimation and sometimes it's a little wrong and it focuses consistently off because there's something off in the calibration. And, it could front focus, it could back focus, as well. And, I know that there are some people out there that would just say (stomp) it shouldn't to that. I spent a lot of money. And that's true, but we are dealing about physical stuff that needs to be manufactured and there are certain tolerances. If you want perfect focus, we could probably do it...

and it would be a $100,000 lens. And, it's just, you know, we would rather have a lens that focuses 99.9% of the time for $1,000. And, so, things are gonna get off when there's mechanical parts and moving parts and there's manufacturing tolerances. And, sometimes, what happens is a camera will hit plus or minus 1% and then, the lens will hit plus or minus 1% and then the two of them will probably be zero but, it could be plus two or it could be minus two and that's when things kind of get thrown off. And, so, in the past, we had to send all of our gear back to the manufacturer and then, they would do something with it and then we get our gear back and now, they allow it, us to fix it ourselves. And, so, if you wanna fix it yourself, you have to test it to see exactly what's wrong with it. And, it needs to be a consistent problem. If you're having a situation where it focuses in front, in back, everything's out of focus but, it's different every time, okay, that's something else. It's where, you know, I'm focusing on the eyes and the nose is in focus on a consistent basis with the same lens all the time. That's the type of problem we can solve here. What you need to do is you need to focus on a subject and you can use a focusing target, a book, or pretty much anything else you want. But, we need to measure if we're actually focusing front or behind it. So, it can't just be a flat object. You can buy a test chart that looks like this or you can make your own which is what I do with rulers and yardsticks. It's pretty easy to do. And, you just gotta line em up and set em up. And, so, I'm gonna focus on the vertical one and I'm gonna measure whether I'm in front or in back. And, so, when you get into the calibration of these cameras, you'll be able to adjust the focus forward or back by one increment. I don't know what one increment is but, it's a really small amount. And, so, this is what my photos would look like. So, I'm adjusting it by minus 20 and plus 20 on the extremes and the yellow arrows indicate where I thought the best focus was. And, so, my camera set at zero is front focusing ever so slightly. So, I would probably set my camera to plus three or maybe plus four, something in that range there. Now, this is something that is not gonna be a major problem for most people most of the time. It's for people who have longer telephoto lenses, people who have very fast lenses who shoot at shallow depth of field on a regular basis. And, so, you're gonna need everything that you would use to get really sharp photos. You're gonna wanna have your tripod, cable release, self timer, things like that set up. You're gonna need to set your camera up to shoot the highest quality images possible at the shallowest depth of field possible and there's a couple different ways that you can do that but, you wanna shoot as shallow depth of field as possible. And, then, what you're gonna do is I unfocus the lens, I let it auto focus, and then I have it take the picture. Now, kind of the one additional step that I'll do is I'll do a couple of photos at each setting. I'll unfocus, take a picture, unfocus, take a picture, and, then, if I really wanna be precise, I unfocus the other direction, so that it has to achieve focus from both directions. I want it to be able to find the right spot from both sides and I'm trying to look for things that are consistent. If it's out of focus every time, then I'm gonna make an adjustment and I'll go forward and back. Now, yeah, I'm kind of a picky guy, and I have some fast lenses so, I like to be right. So, I have to, I hate buying new cameras because I gotta go do the calibration on all my lenses, and I gotta lot of lenses, and I gotta get it all right. And, for the most part, I am adjusting almost all of my lenses a few point forward or back. And, so, if you have lenses that are faster than 2. those are the people that are really gonna need to do it. So, this is for, typically it's Nikon and Canon, anyone who has fast glass and I'm talking about apertures of 2.8 or faster. Talking about telephoto lenses, macro lenses, and portrait lenses, those are the people that are gonna get the most benefit and see some change in it. If it's something erratic, then, you're gonna need to send your camera back to the manufacturer because there's something else going wrong. It's consistent problems that we can fix here.

Class Materials

Bonus Materials with Purchase

Fundamentals of Photography Class Outline
Learning Projects Workbook
Camera Keynote PDF
Sensor Keynote PDF
Lens Keynote PDF
Exposure Keynote PDF
Focus Keynote PDF
Gadgets Keynote PDF
Lighting Keynote PDF
Editing Keynote PDF
Composition Keynote PDF
Photographic Vision Keynote PDF

Ratings and Reviews

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
 

I don't think that adjectives like beautiful, fantastic or excellent can describe the course and classes with John Greengo well enough. I've just bought my first camera and I am a total amateur but I fell in love with photography while watching the classes with John. It is fun, clear, understandable, entertaining, informative and and and. He is not only a fabulous photographer but a great teacher as well. Easy to follow, clear explanations and fantastic visuals. The only disadvantage I can list here that he is sooooo good that keeps me from going out to shoot as I am just glued to the screen. :-) Don't miss it and well worth the money invested! Thank you John!

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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