Camera Lenses for Video – Understanding Lenses for Beginners (Focal Length, Aperture, Focusing)

Camera Lenses for Video – Understanding Lenses for Beginners (Focal Length, Aperture, Focusing)


So you got your camera. Now you need a
lens, but there are so many to choose from. And what do all those millimeters and
“f” numbers mean? You’ll understand it all very soon. Hey guys, Camber back with
you today from Maryland, and we are talking about lenses and which one is
right for you for starting out in video. Now just because a lens can zoom in
really far doesn’t make it a good lens. I’ve heard this way too many times: “Hey man, I just got this new lens for my camera. It goes 55 to 250. I can get
anything with this lens.” And I’m like: Huh, that’s cool. When I’m really thinking: Oh, I wish you would have asked me sooner I know a lens that’s better and
cheaper than that. The reason I bring this up is because that’s where this
thing came from. I thought, oh I can do anything with this lens I don’t have to
buy all kinds of lenses, and I think that I’ve never even used this. So if you look
at any lens you’re gonna see a bunch of numbers written on the side or on the
front of it and those numbers are your focal length, your maximum aperture, and
your lens diameter. So the first number on any lens is going to be the focal
length and that’s measured in millimeters. As you can see here this
lens is 50 millimeters. It’s an actual measurement in millimeters inside your
lens but all you really need to know is that the smaller the number the wider
your angle of view and the higher the number the more narrow your angle of
view. So the next number after the focal length that you’ll find on your lens is
the aperture. It’s a ratio of the focal length to the maximum aperture of the
lens and this one is 1 over 1.4. So your aperture controls how wide your
lens can open to let in more light. So the higher the f-number the smaller the
opening of your camera letting in less light and the lower the f-number gets
the more open your camera lens becomes letting in more light. Now with these
lower maximum “F” numbers your lens is typically going to be bigger and also
more expensive. So that lower maximum F number meaning the wider open your lens
can get will let in more light but also create that blurry background look and
can make your footage look really nice. So the last number you’re gonna see on
the lens is your lens diameter and this one is 82 millimeters. So that last
number gives you the diameter of the front of your lens
so that when you start buying different kinds of filters you’ll know its size to
get to fit your camera lens. Now another thing to consider when it comes to
choosing a lenses image stabilisation. Image stabilization is nice because if
you’re hand-holding your shots it’s not gonna fix it completely but if you’re
being pretty smooth already and it’s gonna help smoothen that out even more.
So now that we know all those different numbers are there’s also two main types
of lenses we want to look at and that’s your prime lens and your zoom lens. So
the difference with these is your prime lens is going to give you one focal
length for instance this one is 50 millimeters whereas this one has a range
of 24 to 70 millimeters. So you might be thinking why would I get the prime lens
of 50 millimeters when I could get the zoom lens it’s 24 to 70 it has 50 in it
and I have all those other focal links to use too. One of the first advantages to
getting a prime lens versus a zoom lens is that your prime lenses are going to
be a lot cheaper because they have fewer moving parts. Also in your prime lenses
since there’s fewer moving parts, fewer pieces of glass in between for all the
different focal links, your prime lens is going to be sharper at 50 millimeters
then your zoom lens is going to be at 50 millimeters. Most prime lenses are going
to be made so they can open up to a lower F number or a wider aperture
giving that more blurry background than your zoom lenses will be able to give
you. And your maximum aperture of your lens is another reason why getting one
of these lenses that can go really far isn’t necessarily that good. Because as
you can see on this lens, it goes from f4 to f/5.6. And what that means, at the
shortest focal length 55 it’s going to be at f/4 and as you zoom in to 250 that
maximum aperture is going to go up to 5.6. Whereas this lens has a maximum
aperture of 2.8 and it stays at that 2.8 throughout the entire range of 24 to 70.
Another thing with lenses are manufacturers make certain types that
are only for crop sensor cameras. These lenses are typically going to have that
variable range in aperture which makes them less expensive. So if you put
a crop sensor lens on a full-frame camera you’re going to get this vignetting
around the corners because this lens is designed for the camera with the smaller
sensor. Whereas when we switch back, now that vignette around the edges is gone
because this lens is designed for a full-frame camera. So you can use a
lens designed for a full-frame camera on any camera, however, if you use the crop
sensor lens on a full-frame camera it’s going to give you that vignette around
the edges of your picture. If you don’t understand what I mean by crop factor,
check out this video I made here talking about how your sensor size of your
camera it’s gonna affect what the focal length of your lens looks like. So one
last thing to consider when you’re choosing a lens is the focus and what I
mean by that is whether it’s mechanical or electronic focus. As you can see on
here, as I turn the focus ring you can see different numbers for measurements
on where the camera is focusing. So when you’re setting up focus pulls on these
kind of lenses and you know where exactly your different focus elements
are gonna be you can set where you’re gonna hit those focus points. Whereas you
look at this lens, there’s no distance markers. All you have is a spinning focus
ring that never stops because this lens has an electronic motor. So as you turn
this it sends a signal to that motor and changes the focus in your camera, but if
you’re trying to pull focus with one of these it’s really hard to do because the
speed at which it focuses is inconsistent. The faster you turn it the
quicker it’s gonna get to your focus point; so you can’t just set one place
and go there every time because if you go faster or slower than before then
it’s not going to get that same focus at the same point. But if you have a nice
autofocus system they work really great. Especially if you have a good touch
screen where you can pick your points and it’ll pull focus consistently and
perfectly on the points that you want. So starting out, I would definitely suggest
getting a nice zoom lens because then you do have that wide range of shots. And
zoom lenses can be quite pricey so if you were gonna start with something else,
I would definitely say pick up one of these 50 millimeters. This is Canon’s
version. It will run you $125, it can open up to f/1.8 giving you a really
blurry background. Remember that investing in good lenses now is going to
pay off now and in the future because it’s going to improve the quality of
your shots now and also as you improve your cameras in the future you’ll be
able to use those same good lenses on those new cameras. So that was a lot of
stuff to cover but if you made it this far go ahead hit that thumbs up. Leave a
comment down below about what your favorite lens is or which one you want
to get and why. I got links in the description for a lot of great lenses
whether you’re rocking Canon or Sony so check those out. Subscribe if you haven’t
and remember that the only way to get better at something is to practice. So get that
lens, get out there, and film something. See you soon!

8 thoughts on “Camera Lenses for Video – Understanding Lenses for Beginners (Focal Length, Aperture, Focusing)”

  1. Good stuff as always. I’d like to add that lens maintenance and care is also critically important, as it always making sure to replace your lens back and lens cap when the Lens is not in use. Also, you’ll probably cover filters in another episode, but I always recommend getting at least a cheap UV filter for general protection, it’s saved my lenses multiple times.

  2. I have been watching a few of your videos now. I am find them really helpful. I brought myself a 50mm canon prime lens. Just want look at this video https://youtu.be/Jk-lkAk66hQ
    And I don't think I have my slow motion right. It's was filmed 50 fps and editing in final cut pro at 60 fps should it be at 24??

    Any other tips would be great. Like how to get those super smooth b-roll shots would be great

    Matt

  3. So what lens did you get instead of the 55-250mm IS STM? I was thinking of getting that on sale to try out a telescopic/portrait for $120… JC ^.^

  4. Dude, thank you for giving the basics in such a clear, concise and efficient way! And breaking each subject down in a separate video is Very helpful to focus on one subject at a time. Thank you!

  5. I don't understand what is the difference between aperture and focus ring on the lens can any one explains that to me ?

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