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Fundamentals of Photography

Lesson 29 of 107

Lens Quality


Fundamentals of Photography

Lesson 29 of 107

Lens Quality


Lesson Info

Lens Quality

All right, a final little section here on lens quality. And so we talked about the angle of view, we talked about the aperture, but there's also a few things that impact the image quality that you're gonna get from any particular lens. So, first off, we wanna talk about some of these optical challenges in making lenses. And we wanna have lenses with the highest resolution possible, and there is no rating on this, as far as a number, when you buy your lens, but lenses tend to be getting sharper because we have higher resolution cameras now. And so there are some older lenses which are quite nice but on newer cameras, with higher megapixels, they don't stand up as well as they used to back in the days of film and lower resolution sensors, and so that's one of the things that we're getting just inherently in the newer lenses. Some lenses deal with flare better than other lenses, and so when light strikes the front of the lens, it causes ghosting and light hitting different parts of the se...

nsor, and so this is why you wanna use a lens hood, and why some lenses are better corrected for lens flare than others. I talked about diffraction, when we stop our aperture down. And so what happens is that, when we stop our aperture down, the light hitting those aperture blades gets diffracted, sent in slightly different directions, which causes just a little bit of blurriness. So stopping down to f22 and 32 is not recommended, unless you really need it, because it's gonna cause a loss of sharpness on any particular image. Chromatic aberration. Chromatic, color. Aberration, ghosting. Color ghosting will occur when you are shooting a solid object that has light behind it, and so as the light comes around the solid object, the light kinda gets a little misdirected, and it doesn't land in the right spot on the sensor, and you get this color ghosting. Now, this can be corrected sometimes in camera. You can turn on chromatic aberration correction, or you can do it in post-production in a program like Adobe Lightroom. Hit the checkbox and it knows what lens you have, how bad that problem is, and can automatically fix it. Or you can even go in and manually fix it, where it looks for edge lines of a certain color and corrects it and de-saturates it, basically. And so it's something that'll happen even with the best of lenses in bad conditions, you might say. Distortion is something we talked a little bit about before. Barrel distortion is more common on wide angle lenes and pin cushion distortion is a little bit more common on telephoto lenses. And all lenses should be perfectly corrected, but the reality is is that all lenses have a little bit of distortion, and to fix this, programs like Adobe Lightroom will have a little checkbox or they'll have a slider where you can fix this up later. In most images, you're not gonna notice this is a problem, but if you have buildings and straight lines, you might see that and you might wanna correct for that, if you have a lens that has a bit of an issue with these. Vignetting is something we talked about earlier. It's a darkening of the corners, and sometimes we like it and sometimes we don't like it. It depends what type of photograph it is, and what you want from the photograph. This is a problem of fast lenses, wide angle lenses, and cheap lenses. In the early days, some of you might remember, we had TVs that had rounded corners, and that's because the image was really dark and blurry in the corners, because the lenses weren't very good at getting sharp edges. So they just said, "Well, let's just make it like this." And there were some TVs that were round, because they had really bad lenses, I think, at the time, and they couldn't get anything sharp from the corners of them. The bokeh, the quality of the out of focus area, and you know your getting picky about lenses when you're worried about the bokeh of this. And I'm not even going to get into the how do you pronounce it thing. There's a whole thing on the internet about it. I call it bokeh, it's my class, that the way I like to call it. (instructor and students laughing) So, a good bokeh is gonna have a smooth and creamy out of focus area. The bad bokeh, you might be able to see an outline of the aperture, and it's a little bit more jittery and less smooth, and so this is something that some people will grade and qualify. There is no number on this, it's just more of a feeling, it looks more smooth than it does over here. On the right hand side, it's not very good. It kind of goes bright and dark very, very quickly there. And so some lenses are a little bit better than other lenses. Construction of the lens. This is really important to me. I like working with a lens that feels good in the hand, that's comfortable, that focuses smoothly, has nice click stops on the apertures, things like that. And so, metal lens mounts, because I tend to change lenses a lot. The less expensive lenses will use plastic lens mounts. I like a real focusing ring with a rubber grip on it, so that I have a good area to grab onto. Distance scales, and there's other factors in here we'll talk more about as we talk about lenses. But there are some pretty big differences between the lowest end and the highest end lenses. And so, it's not just optical quality, it's the entire quality of that entire product that you're gonna be looking at. And so, when it comes to the optical hierarchy, of what are the best lenses and what are the worst lenses, it generally falls into this category of professional prime lenses, and so a prime, like a 200mm lens, is gonna be a really high quality lens. Next up is gonna be a prime lens, just your standard 50 or 35mm lens. They're not necessarily quote unquote pro lenses, they're just prime lenses. They're gonna be very, very sharp. Next up are your professional zooms, your 24-70, 70-200, 2.8. Kind of next down on the list of sharpness are gonna be your standard zooms. Now, the difference between the 18-55 and the 200... Noticeable, but not huge. You could shoot a cover of next month's National Geographic or whatever magazine you wanna think of with any of these, would be my guess, if it's a good subject. But when you get into the pixel peeping, you will notice greater sharpness with those primes, and especially those high end primes. The lowest on the list are the superzooms, the ones that zoom a really large range, you know, the jack of all trades, master of none philosophy. If you design a lens to try to do everything, sharpness is going to suffer a little bit. And what I have found is that teleconverters will take any lens and lower it by one step on this list. And so, what you probably don't wanna do is put a teleconverter on an 18-200 superzoom lens. Kind of falls off the chart then. But, if you use it on a high quality lens, you'll be getting decent results still, but it's gonna lower it just a little bit from its original native abilities without using teleconverters. We'll talk more about teleconverters in the gadget section in this class.

Class Description

Short on time? This class is available HERE as a Fast Class, exclusively for Creator Pass subscribers.

As a photographer, you will need to master the technical basics of the camera and form an understanding of the kind of equipment you need. The Fundamentals of Digital Photography will also teach something even more important (and crucial for success) - how to bring your creative vision to fruition.

Taught by seasoned photographer John Greengo, the Fundamentals of Digital Photography places emphasis on quality visuals and experiential learning. In this course, you’ll learn:

  • How to bring together the elements of manual mode to create an evocative image: shutter speed, aperture, and image composition.
  • How to choose the right gear, and develop efficient workflow.
  • How to recognize and take advantage of beautiful natural light.

John will teach you to step back from your images and think critically about your motivations, process, and ultimate goals for your photography project. You’ll learn to analyze your vision and identify areas for growth. John will also explore the difference between the world seen by the human eye and the world seen by the camera sensor. By forming an awareness of the gap between the two, you will be able to use your equipment to its greatest potential.


  1. Class Introduction
  2. Photographic Characteristics
  3. Camera Types
  4. Viewing System
  5. Lens System
  6. Shutter System
  7. Shutter Speed Basics
  8. Shutter Speed Effects
  9. Camera & Lens Stabilization
  10. Quiz: Shutter Speeds
  11. Camera Settings Overview
  12. Drive Mode & Buffer
  13. Camera Settings - Details
  14. Sensor Size: Basics
  15. Sensor Sizes: Compared
  16. The Sensor - Pixels
  17. Sensor Size - ISO
  18. Focal Length
  19. Angle of View
  20. Practicing Angle of View
  21. Quiz: Focal Length
  22. Fisheye Lens
  23. Tilt & Shift Lens
  24. Subject Zone
  25. Lens Speed
  26. Aperture
  27. Depth of Field (DOF)
  28. Quiz: Apertures
  29. Lens Quality
  30. Light Meter Basics
  31. Histogram
  32. Quiz: Histogram
  33. Dynamic Range
  34. Exposure Modes
  35. Sunny 16 Rule
  36. Exposure Bracketing
  37. Exposure Values
  38. Quiz: Exposure
  39. Focusing Basics
  40. Auto Focus (AF)
  41. Focus Points
  42. Focus Tracking
  43. Focusing Q&A
  44. Manual Focus
  45. Digital Focus Assistance
  46. Shutter Speeds & Depth of Field (DOF)
  47. Quiz: Depth of Field
  48. DOF Preview & Focusing Screens
  49. Lens Sharpness
  50. Camera Movement
  51. Advanced Techniques
  52. Quiz: Hyperfocal Distance
  53. Auto Focus Calibration
  54. Focus Stacking
  55. Quiz: Focus Problems
  56. Camera Accessories
  57. Lens Accessories
  58. Lens Adaptors & Cleaning
  59. Macro
  60. Flash & Lighting
  61. Tripods
  62. Cases
  63. Being a Photographer
  64. Natural Light: Direct Sunlight
  65. Natural Light: Indirect Sunlight
  66. Natural Light: Mixed
  67. Twilight: Sunrise & Sunset Light
  68. Cloud & Color Pop: Sunrise & Sunset Light
  69. Silhouette & Starburst: Sunrise & Sunset Light
  70. Golden Hour: Sunrise & Sunset Light
  71. Quiz: Lighting
  72. Light Management
  73. Flash Fundamentals
  74. Speedlights
  75. Built-In & Add-On Flash
  76. Off-Camera Flash
  77. Off-Camera Flash For Portraits
  78. Advanced Flash Techniques
  79. Editing Assessments & Goals
  80. Editing Set-Up
  81. Importing Images
  82. Organizing Your Images
  83. Culling Images
  84. Categories of Development
  85. Adjusting Exposure
  86. Remove Distractions
  87. Cropping Your Images
  88. Composition Basics
  89. Point of View
  90. Angle of View
  91. Subject Placement
  92. Framing Your Shot
  93. Foreground & Background & Scale
  94. Rule of Odds
  95. Bad Composition
  96. Multi-Shot Techniques
  97. Pixel Shift, Time Lapse, Selective Cloning & Noise Reduction
  98. Human Vision vs The Camera
  99. Visual Perception
  100. Quiz: Visual Balance
  101. Visual Drama
  102. Elements of Design
  103. Texture & Negative Space
  104. Black & White & Color
  105. The Photographic Process
  106. Working the Shot
  107. What Makes a Great Photograph?


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.


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!


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