Behind the Glass Part 1: An Introduction to Lenses

A camera without a lens is like macaroni without cheese, a ship without sails, Simon without Garfunkel... you get the point. Your lens is an important, multitasking gadget, allowing you full control over a variety of aspects to your shot. Aperture, focus, and focal length are all dictated by this handy device. But don't take our word for it! Camera guru, Vincent LaForet is here with Blake to show us the basics on what lenses do and how to pick one that is best for your project. Check out the video below!


Aperture
The aperture is the diameter of the lens opening. The larger the diameter of the aperture, the more light reaches the film or image sensor. The aperture also performs a critical function for focus. As the aperture decreases in size, the background and foreground gain sharpness. This zone of sharpness is called the depth of field.

Aperture is expressed as F-stop and will be indicated on your camera in abbreviations that look like this: F2.8 or f/2.8.
The "F" stands for the focal length of your lens, and the number indicates the diameter of the iris opening. (For a more in-depth explanation, head over to this lesson!)

Focus Ring
Located around the barrel of your lens, this helps you focus the image. Some lenses will also have an auto focus switch, which means that your lens can do the focusing for you on those days that your eyes are feeling a little tired.

Prime or Fixed Lens vs Zoom Lens
A prime lens has a fixed focal length, whereas a zoom lens has a handy ring that allows you to switch to different lens equivalents within the single lens. But don't knock prime lenses entirely! They may be less versatile than a zoom, but they often have superior optical quality, are lighter weight, smaller bulk and cheaper.

PPro tip: No matter what kind of lens you're using, always try to zoom by foot (aka- walk yourself closer) to get near to the subject. This will always provide superior quality as opposed to trying to zoom in with the lens.

A Lens for Every Occasion!
Various lenses are suited for specific applications. Lets have a look at some common lenses and what they do.

16mm- An ultra wide lens, this bad boy distorts heavily, emphasizing objects in the foreground by making them look a lot larger than the background. Dynamic, but use with caution!
28mm- Standard for documentary and photojournalism to shoot cowboy shots, otherwise known as medium shots.
35mm- Another standard for documentary filming, also tight enough to shoot portraits.
50mm- Standard for cinema/video, it approximates the human eye's typical focal length.
85mm- A popular portrait, or "beauty" lens. Capable of making everyone look lovely!
200mm- The top of the scale for most people, this is a telephoto lens. Their inherent shallow depth of field makes them useful in eliminating unwanted foreground and background objects by simply throwing them out of focus. Great for sports photography!

Now that we've had a friendly overview, let's take a closer look at the wonders of focal length and what that means for your video. Onward to Episode 2!

Category:
DSLR
Gear
Shooting
Difficulty:
Beginner

14 Comments

alexdez

alexdez

Thanks a lot!
It was worth to learn something "new" about aperture just to see Vincent LaForet's incarnation as a brutal viking!
Looking forward to see next episodes!

AKA  AL alien

AKA AL alien

LOL This is great but I usually push buttons and turn stuff to see what it dose But thats just how I learn great Info thanks c];-D

Nicholas Lam

Nicholas Lam

Why does Vincent favour lenses in this way? "My favorite focal length is..." It depends on the story Vincent! A 24mm for instance on an APS-C sized sensor can help to exaggerate and pull the subject out of the scene and closer to the viewer.

David Stotz

David Stotz

I'm sure most people for whom this video is targeted will be using some sort of cropped-frame camera (APS-C or four-thirds), but VIncent Laphoret was talking about the various focal lengths in terms of their usefullness in a full-frame, large sensor camera. Most people will not have these same experiences with these lenses. With a crop-frame camera all those focal lengths will be about 1.6 - 2 times longer, drastically altering the way they behave. For instance, on these cameras, a 24mm lens is not wide angle at all, and a 50mm is a telephoto lens.

Richard Wood

Richard Wood

This is good for somebody starting out in photography or videography but is perhaps a little basic for people who have already a lot of pictures under their belts.

Sam Sloan

Sam Sloan

They didn't discuss crop factors... :-/

Giustino Bruno

Giustino Bruno

Sicuramente chi ha l'occasione di vedere il video potrà farne tesoro :-)

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Lesson Summary

Join Blake as Vincent Laforet explains the world of lenses. Learn how to distinguish a prime from a zoom lens and more!

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