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Focal Length

Lesson 3 from: Choosing the Right Camera Lens

John Greengo

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Lesson Info

3. Focal Length

Next Lesson: Normal Lenses

Lesson Info

Focal Length

Alright. We're gonna talk about the focal length of the lens. This is what you see from side to side in a lens, and it's the lens's most important characteristic. And so we're talking about our angle of view. We're gonna talk about the different types of lenses in here. I've grouped 'em into normal lenses, wide lenses, and telephoto lenses. Now for this section, it doesn't matter whether you have a prime lens or a zoom lens. All that matters is that you can get to that number that we're talking about. So, let's talk about those numbers. If we have a camera, and we have a 50mm lens on it, with a full-frame camera this is what we're gonna see from side to side. As we see more from side to side, we're getting into the world of wide-angle photography. And there's moderate wides, there's just kind of normal wide angles, and then there are ultra-wide angles when you get wide enough. When you see a narrower angle of view, you're talking about a telephoto lens. And they will sometimes be refer...

red to as short, medium, or super-telephoto lenses. Now, all the numbers that you see on screen in red here are in relationship to what you would see with a full-frame sensor, because remember, in the previous section, I said that that is the standard that most people, including myself, are gonna be talking about lenses. But I know, 'cause I've taught a lot of classes, that most people in photography right now with interchangeable lenses are using a cropped frame sensor, very similar to ones used in Sony and Nikon and Canon. And so they're gonna have about a 1.5 to 1.6 crop factor. So if you have one of those cameras, you may wanna pay more attention to the blue number on the bottom, because to get that angle of view, that is the lens that you would need in there. Now, if you wanna measure what you can see with a lens, there are multiple ways of doing it. You can measure, if you want, horizontally, you can measure diagonally, vertically. And the way that I'm gonna be doing it for my class is horizontally, 'cause that's how people usually hold the camera, and they kind of think straight from side to side across. What do you see from side to side? So let's take a look at what different lenses look like in one of my favorite photographic locations, is the road down in Arizona that leads to Monument Valley. And so I gotta be careful about this, but if you were standing out in the middle of the road with a 50mm lens, this is a very realistic look of what it looks like to look down this road. Now as we go into the world of wide-angle, now remember, full-frame users look to the top of the screen, where we're talking about focal length, and the crop-frame users, over to the right-hand side, and if you have a micro 4/3 system, you take the top number and you divide it by two. They have a little extra math homework on them for this project here. So we're gonna go into the world of wide-angle. 35 is considered a modestly wide lens. As many of you know, 24 is one of my favorite wide-angle lenses, an I'll talk about that more in a little bit. But one of the things you'll notice as we go to 16mm and ultra-wide is, look how much foreground takes up the scene, compared to where we were in the 50mm. So one of the things we'll talk a lot about in wide-angle lenses is foreground material. And this is very important to landscape photographers, 'cause they're often looking for flowers and bushes and rocks and sticks and branches to photograph in the foreground along with a beautiful background in there. So, we're gonna zoom back up to 50mm, going through our equivalents here, modestly wide, back to our normal lens at 50. And we're gonna enter the world of telephoto. So 100mm would be considered a short telephoto lens. And let's get ourselves up to 200, where we can start seeing some compression. Now this is when you are using a longer telephoto lens. The compression effect is much easier to see, 'cause it's happening all over the frame. Now that road that you're looking at onscreen is very far from the butte in the background. It's about five miles from there. And compression refers to the fact that you're looking at two objects that look like they're kind of compressed together. And you're gonna get that very clearly when you're shooting with two, 400, and even longer lenses. So let's go ahead and bring this back down to to get our normal view once again, and we'll be able to see what our crop factor was at 100, 200, and 400. So all these different lenses are just simply different angles of view for telling different types of stories. And each one is good at something that's a little bit different.

Class Materials

Bonus Materials with Purchase

Choosing The Right Camera Lens Handout (15 pages)

Ratings and Reviews

E.L. Bl/Du

John is one of the best instructors Ive watched. he's clear, concise, and gets right to the point. His display's and diagrams are so great, he makes very complicated subjects easy to understand, and fun. He holds your attention and interest b/c everything he says is valuable. This really helped me understand the vast complicated world of lenses. I would highly recommend this class to anyone who doesnt know what hyperfocal distance is.

Boris Dimitrov

Excellent class packed with incredibly useful knowledge. John is an amazing lecturer. He has also developed really great materials to help explain all the concepts and technologies that are explored in the class. Looking forward to my next class with him!

a Creativelive Student

Great class. So informative. John Greengo is such a fantastic tutor and explains everything in such and easy-to-understand way. I would highly recommend this class. Prior to doing this class, I was so confused about which lenses are best for various photography. Now I understand lenses completely. Thanks John!

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