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Canon Lenses: The Complete Guide

Lesson 15 of 58

Aperture: Flare


Canon Lenses: The Complete Guide

Lesson 15 of 58

Aperture: Flare


Lesson Info

Aperture: Flare

But the flare shape is also determined by the aperture. You can actually look in here and you can count the blades on the aperture by the type of flair in here. And for instance, on this lens, I can tell I have 12345678 bladed aperture in this lance. And so our standard apertures are these straight edges. This is the easiest way to build an aperture, and you will see kind of the lower end lenses built with this type of design. One of the things that you might see listed under the characteristics of a lens is a rounded aperture. And what this means is they put a little curve in the aperture, and I don't design and build lenses myself. But I believe this complicates the process of them opening and closing in the way they actually have to move in and out. But this is preferable so that we have a rounder out of focus area, which doesn't look awkward, cause imagine if we had a three bladed aperture and we had these triangles on our images in all our flare areas, it would look quite awkward.

And so you want to have, ah, lot of blades and you wanna have them rounded. Or even better, you want a truly round aperture so that these air all curves so that when they stop down, they form a perfect circle. But this perfect circle is very hard to create because they're trying to create perfect circles for all the different apertures, and that's why they typically get a rounded one. It's kind of a compromise with the largest versus the smallest aperture. It's all pretty close to round. There are a few lenses that were ableto have nearly perfectly round aperture settings on him, and those tend to have very nice flare areas because they're very natural looking. This also has an impact on the bouquet or the out of focus area of our photograph. We're gonna talk about that in a later section as well. And so how many blades is in your lands? It's not a critical factor on which lens I would choose to buy, but it's something to be aware of because it has an impact on our final photographs, and I always seem to get questions on Starburst. I think I've answered him, but I Well, let's just check in on any other questions that we might need to catch up on. Yeah, I love that starburst affection. Um, so w M. C. Ward had asked him. This is just going back to diffraction. Um, so would my seven d mark two, which would be a crops and circle, have the same diffraction as my five d. Since if the pixel sizes are about the same, Yes. So it's the pixel size, not the sensor size. And so it would. I was about to say no, but I didn't really hear what was the other camera waas. And so there are technical places. For instance, DP Review is a great local site that international, but they're located locally here. And if you go into this, the pages about the camera reviews somewhere buried in there will be in the specifications pixel size, and it's measured in micro meters, and it's gonna be like 2.3 or 4.9, and you can actually check the pixel size off the camera that you were using. And you can compare that with the other cameras that you might have to see where that might be So that a reason to at that point B a pixel peeper. We're getting into that territory. And that's one of the things that I want to avoid a little bit. I mean, we're comparing lenses, but we're not gonna be going in incredible detail and comparing the that close of detail between lens and lens word. We're trying to do the big scope here, right? But that so that the size of the pixel is that is different than saying, This camera has 20 megapixels and this camera has 20 megapixels that you could have you could. Well, I'm not sure what you're asking, but you could have two cameras that have 20 megapixel right that have different Lett's add on top of 20 megapixels, 20 megapixels, same size sensor. They could have slightly different size pixels. It's possible because there is the gap between the pixels and that could very generally they would probably be very, very close. But you could you could pretty summarize going. Oh, this camera has 50 megapixels, and this one has 24 they're the same size sensor that 50 has gotta cram a lot more little pixels in there. And so they're probably a lot smaller. But if they were, if there were two different size sensors, then you got to go back to the looking at the individual pixels. And so one of the areas where this is concerned people is that Cannon has recently introduced a megapixel camera. Okay, so you got 50 megapixels. What does that mean? Smaller pixels packed into that same size area, and this is drawn the attention of some landscape photographers because landscape photographers love intricate little small detail. But landscape photographers also like stopping their lens down to F 16 and F 22. And that's one of the questions that people need to answer is if they're landscape photographer, which I do a fair bit off and you stop your lens down to 22. Do you get too much to fraction on a five DS 50 megapixel camera and you have to back up to F 16 or F 11 in order to hold the sharpness that you need for your photography? And so this is potentially one of the limit points of how far we're going to take pixels. Yeah, 100 megapixel. Sure, that might be fun, but we're gonna have a lot of diffraction. How about how about a 1,000,000 pixels? We're gonna have diffraction at F 2.8 and so we're gonna have to improve the quality of our lenses if we wanna have pixel levels that are that small and in that great of numbers. And so there's a bit of, ah tech war between the lenses and the sensors that we can't have higher quality sensors until we have higher quality lenses. And if you are upgrading your camera, you need to upgrade your lenses to match that, because you gotta have kind of equivalent items to work well together. Where on my lens does it say the number of blades? It doesn't, it doesn't. But if you look in the instruction manual, if you look at the data online about your lands ah, good website would list that in the specifications. However, if you do take a photograph of yourself a selfie and you use a really long exposure like one second, you'll see all the blades, and if you do it long enough, you'll be able to count them

Class Description

Working with interchangeable lenses can be both exciting and daunting to all levels of photographers. Canon® Lenses: The Complete Guide with John Greengo will prepare you to select the right lens and get the most out of all of your lens investments.

John Greengo is the master of making complex photography concepts easy to understand and in this class, he’ll bring all of your Canon EOS DSLR lens options and operations into focus. 

You’ll learn about: 

  • Focal length and aperture
  • Canon zoom lenses
  • Which lens accessories to buy
  • Third-party lenses
  • Maintaining a lens system

John will cover the full range of Canon lenses, from ultra-wide to super-telephoto, zooms to primes, fisheye to perspective control. You’ll learn how to match the right lens to your needs and get insights on the best ways to use it.

Whether you are thinking about buying a new lens or just want to get the most out of what you already have, Canon Lenses: The Complete Guide with John Greengo will help you out.


  1. Class Introduction
  2. Canon Lens Basics

    John Greengo gets you up-to-speed on the basics of working with interchangeable Canon® lenses.

  3. Focal Length: Angle of View
  4. Focal Length: Normal Lenses
  5. Focal Length: Wide Angle Lenses
  6. Focal Length: Telephoto Lens
  7. Focal Length Rule of Thumb
  8. Field of View
  9. Aperture Basics
  10. Aperture: Maximum Aperture
  11. Aperture: Equivalent Focal Length
  12. Aperture: Depth of Field
  13. Aperture: Maximum Sharpness
  14. Aperture: Starburst Effect
  15. Aperture: Flare
  16. Aperture: Hyperfocal Distance
  17. Camera Mount System
  18. Canon Lens Compatibility
  19. Canon Lens Design
  20. Canon Lens Composition
  21. Canon Lens Shape
  22. Canon Lens Coating
  23. Canon Lens Focusing
  24. Lens Autofocus
  25. Canon Lens Image Stabilization
  26. Canon L Lenses
  27. Image Quality
  28. Canon Zoom Lenses: Standard
  29. Canon Super Zooms
  30. Canon Wide Zooms
  31. Canon Telephoto Zooms
  32. Prime Lens: Normal Lenses
  33. Prime Lens: Moderate Wide
  34. Prime Lens: Wide Angle
  35. Prime Lens: Ultra-Wide
  36. Prime Lens: Short Telephoto
  37. Prime Lens: Medium Telephoto
  38. Prime Lens: Super Telephoto
  39. 3rd Party Lenses Overview
  40. 3rd Party Prime Lenses
  41. 3rd Party Zoom Lenses
  42. Lens Accessories: Filters
  43. Lens Accessories: Lens Hoods
  44. Lens Accessories: Tripod Mount
  45. Lens Accessories: Extension Tubes
  46. Lens Accessories: Extenders
  47. Macro Lens: Reproduction Ratio
  48. Macro Lens: Technique and Choices
  49. Fisheye: Technique and Choices
  50. Tilt Shift: Techniques and Choices
  51. Make a Lens System Choice
  52. Choosing A Portrait Lens
  53. Choosing A Sports Lens
  54. Choosing A Landscape Lens
  55. Best Lenses for You
  56. Lens Maintenance
  57. Buying and Selling Lens
  58. What is John Greengo's Favorite Lens?



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!

a Creativelive Student

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!


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!