Lessons
Class Introduction
07:11 2Canon Lens Basics
14:12 3Focal Length: Angle of View
11:31 4Focal Length: Normal Lenses
09:43 5Focal Length: Wide Angle Lenses
18:15 6Focal Length: Telephoto Lens
21:27 7Focal Length Rule of Thumb
15:36 8Field of View
10:14Aperture Basics
04:41 10Aperture: Maximum Aperture
18:44 11Aperture: Equivalent Focal Length
07:48 12Aperture: Depth of Field
06:23 13Aperture: Maximum Sharpness
08:33 14Aperture: Starburst Effect
05:18 15Aperture: Flare
06:48 16Aperture: Hyperfocal Distance
19:32 17Camera Mount System
14:57 18Canon Lens Compatibility
14:26 19Canon Lens Design
12:29 20Canon Lens Composition
04:30 21Canon Lens Shape
05:50 22Canon Lens Coating
06:53 23Canon Lens Focusing
14:10 24Lens Autofocus
08:17 25Canon Lens Image Stabilization
06:57 26Canon L Lenses
10:18 27Image Quality
09:46 28Canon Zoom Lenses: Standard
17:50 29Canon Super Zooms
05:20 30Canon Wide Zooms
09:48 31Canon Telephoto Zooms
16:09 32Prime Lens: Normal Lenses
09:19 33Prime Lens: Moderate Wide
07:01 34Prime Lens: Wide Angle
05:33 35Prime Lens: Ultra-Wide
09:23 36Prime Lens: Short Telephoto
09:03 37Prime Lens: Medium Telephoto
08:59 38Prime Lens: Super Telephoto
13:59 393rd Party Lenses Overview
06:01 403rd Party Prime Lenses
15:25 413rd Party Zoom Lenses
26:28 42Lens Accessories: Filters
33:42 43Lens Accessories: Lens Hoods
09:58 44Lens Accessories: Tripod Mount
04:51 45Lens Accessories: Extension Tubes
04:30 46Lens Accessories: Extenders
13:11 47Macro Lens: Reproduction Ratio
18:59 48Macro Lens: Technique and Choices
25:59 49Fisheye: Technique and Choices
18:49 50Tilt Shift: Techniques and Choices
27:08 51Make a Lens System Choice
05:37 52Choosing A Portrait Lens
17:21 53Choosing A Sports Lens
17:31 54Choosing A Landscape Lens
10:39 55Best Lenses for You
08:46 56Lens Maintenance
11:19 57Buying and Selling Lens
11:15 58What is John Greengo's Favorite Lens?
08:37Lesson Info
Canon Lens Shape
So we got our glass compounds. We've got the glass that we got the type of glass we're gonna do now. Once we have this, we need to shape it all right. Now, most lenses are gonna be shaped into a spherical, rounded type element and that works out well for most lenses. We can you do that most of the time and it's gonna come out fine, but from time to time, depending on the chemical compound, depending on the way the light travels through. Here are red, blue and green points of light. Don't end up in the right area. How do we fix this? Well, one of the solutions is to create an ass spherical element that has a non perfectly smooth exterior. It's it is smooth, but it's not a rounded in the way that a spherical forms of sphere alright. And by doing that, if they do it just right, they can fix this problem. So this could potentially reduce spherical aberrations astigmatism, and it can also reduce the number of elements, which means we can make a smaller lands. You'll find these in white angl...
es, lardo, large aperture lenses and compact zooms where they're really trying to reduce the size of the lens quite a bit. And so there's a long list of lenses that are using this aspirate kal glass. And as I say, I'm not involved in the process of making. But I would think polishing a spherical element is a whole lot easier than an astrological one, because the types of machines they have will take, like, 40 lenses in them and just be kind of rubbing them all around, smoothing them all up when it comes to ask Miracle. It's a whole different system that they had to develop in order to work with these types of glass elements. And so there are different types of s mericle elements, ground and polished. That sounds pretty good to me. Molded glass not quite as good, so they just kind of form it in that shape rather than grinding it down. And then there are precision moulded plastics that they will use, and that's more likely to be found in some of their point and shoot and smaller in cameras. And so they are technically plastic lenses in there, which some people are very concerned is that a glass lens or plastic lens. Well, you know what that they could do with plastics. They could make him as good or better than standard glass. D o stands for diffraction optics, and it's only used in a couple very unique, very special lenses from Canon. So one idea says, we're all designing our lenses right is Excuse me. What if we just made everything smaller when it that I mean OK, here's our big lands. Let's just make the lens and all the lens elements smaller. What's the problem with that? Can't we just reduce everything? Well, if we do that, it's quite possible that are light rays once again, do not end up at the same point and we're not getting sharp focus. So nice idea. Just reduce everything, make everything half the size and it will work doesn't always work that way. So another solution that they found was a diffraction of scratch structure, and they found that this was fairly good, and they could use this to focus the light in on the sensor and get a pretty good image out of it. But it wasn't perfect. Perfect. Some of the light dispersed off to the side. How do we fix this out and what they're currently using is they're using a dual layered, multilayered refractive structure that corrects for these problems. Redirects light properly in, and they're able to reduce the size of the lens significantly in some cases in order to get a nice, sharp image. So they designed a 400 millimeter F four lens, and they said, You know what? This thing is going to be 31.7 millimeters in length. They know this stuff ahead of time, exactly what they're going to need. But we want to design something that is significantly smaller with these new optics. And this is how they came up with their 400 d o. D fractal optic lens. They just introduced their second version of this. And if you compare what a normal 400 is versus the D O, it is a big savings in size and in wait. So 27% smaller, 31% lighter in size. Very nice thing to have. You will also find this in another lens that they have. They have a standard 72 300 lands pretty typical. It's 14 centimeters, almost six inches in height. They do have a triple layer Dio design in their 300 d Oh, let's 30% smaller, 18% lighter. This is all well and good, but life is not perfect in the world of D. L. Because of the way the lenses air cut, he will sometimes get flare issues that don't look like flare from a normal lens. And they can't just implement this on every single lens. It just doesn't work out, which is why we don't see it on everything out there. There's only this compact zoom. There is the old 400 the new 400 which, by the way, is much sharper than the old one that has this dio technology. They kind of let it lie dormant for about 10 years, and I kind of wondered if they were going to do anything more with it. Because, optically speaking, the 400 the 72 300 are among the weaker canon lenses when it comes to sharpness and overall image quality. And so it's not a perfected technology, but I will have to say that the 400 F four and all the image tests that I've seen is pretty darn phenomenal. It looks really, really good. And so maybe they have kind of figured out any of the little bugs in there because it's looking really good these days on that latest lens, at least so that's a special lens designed for those lances.
Class Materials
Bonus Materials with Purchase
Ratings and Reviews
user-b3a96c
I so appreciate what a good teacher John is. I wish I would have known this much about lenses when I first started out buying my lenses. It was hard finding information about lenses. I didn't want to spend money on a lens I wouldn't use. The better understanding we have about our gear the better photographers we will be. I have never seen a class like this. Invaluable...yes I bought the class! I am really impressed with the high quality photography classes available on Creative Live!
Tami Miller
Have loved the other John Greengo classes I've watched & purchased - and this is another winner! Having been a high school/college science teacher, it is refreshing to take a course with someone who not only is extremely experienced, seems to be a computer having stored so much knowledge, but is equally concerned about making the information truly understandable to different levels. And he shares the information using every tool he can: slides, video, interactive presentations, and great quizzes. I learned so much about my Canon lenses - and lenses in general with their many components. I am excited about testing each of mine to see what macro ratio they handle, and especially appreciated the tutorial on testing each for their specific quirk that affects super sharpness. This class is great whether you own Canon lenses or not. Thanks John Greengo!
Abbeylynne
This was a great class not just about the lenses that Canon offers but also how each lens works. As usual, John's slides are alway informative and entertaining. There is a phrase: John has a slide for that! I am not even a Canon user and found this class to have great information for the use of each specific lens. Great work John! Thank you Creative Live for another great class!