the thing that gives your digital SLR camera the edge
is the ability to change the lens it's in the lens that all the magic happens
and there's a lot of magic out there to capture. once you know how to control
your lens,
you can really start to bring stuff alive in your photography.
Now what are the different types of lens? The one you're most likely to get with
your camera
is a zoom. This one I've got on here is a very standard zoom. It's an
18 to 70 millimeters zoom.
This is a kit lens, which actually came with the camera I bought years ago and I kept it
because it is a crackling good quality lens despite the fact it came as a part of a kit.
what do I mean by 18 to 70?
18 to 70 is the power of
the magnification it's how powerful a zoom you're setting on the lens.
It actually refers to millimeters you may have heard people talk about a
24 millimeter lens or a 10 millimeter lens or
a 200 hundred millimeter lens. That is the power
of the zoom, it's called your focal length. You adjust it by rotating this ring
on the top of the, on the end of the lens here. Some have them back here and some
have them at the front,
but you rotate that ring and adjust the power and there are numbers here
which tell you what you've got it set to. At the moment that's on 18 millimeters,
if I turn it all the way through you can see it goes to 70 millimeters.
This other ring here is for focusing you can set the camera to autofocus which is
what it usually on
but you can also change it to manual if you want to take over and take control
and specifically focus
in a specific place or if the focus is having trouble
getting hold of something you can do it manually, but there are more to lenses
than just zooms there are other types of lens too.
let's take a look at a prime lens for example you may have heard of them.
A prime lenses give you the very best in optical quality,
they're fabulous, they're fantastic but they don't zoom.
the right hand gives it and the left hand takes it away again, you've got fabulous
optical quality but no zoom.
That means you can't just stand here and be lazy and zoom in on something, you've got
to walk up to it or back from it. Now some focal lengths are better than others for
particular jobs.
8500 mill is pretty good for portraiture it's the
rule of thumb it is only a rule of thumb it's not a given rule.
Now if you had all prime lenses you'd have great optical quality
but you'd also have a bag the size of a tank to lug it all around in
and you'd be changing lenses every five seconds.
Possibly getting dust into the camera. That's what a prime lens is.
There are specialist lenses, if I have a ferret around in here, I know I've got one
somewhere. There we go, this weird looking lens
is called a Lensbaby, there are all sorts of specialist lenses.
Now focusing, you're choosing what is how
far away you want the point of focus to be so if I was to focus on you there
you are at about 12 feet away, i'd twist this around or the auto focus
would choose 12 feet and it would focus.
With the Lensbaby you can not only focus backwards and forwards
but when you twist it about like that, you can focus
round and round you can choose a spot of focus and move it around the picture
getting some pretty amazing affects and making people
look at the point you want them to in the picture. A far more common specialist
lens,
would be a macro, now a macro lens is for doing extreme close ups
it means you can focus Incredibly Close to whatever it is you want to take a
picture of.
Let's pop it on the front of the camera,
this is the beauty of a Dslr, you can do this so quickly. You ca completely alter
the characteristics of your camera.
Now if I set this
to its minimum focus, so I'm doing it manually
on auto focus like on any other lens, but i've
set it to manual. If I set this to its minimum focusing distance
and i wanna take a picture of something really close it doesn't zoom,
so you gotta move yourself to the subject. Now
for example my finger, let's just show you what I mean. I'm just gonna do this
and I'm gonna cheat, instead of moving myself i'm gonna move the subject which is my finger nail.
which is slightly grubby but never mind. There we go. As you can see my finger nail is
completely filling the frame.
I can focus that close which is incredible.
Once you enter the amazing world of macro photography almost
anything becomes interesting when you enlarge it to that extent.
what about an old coke an I found on the beach a little way back.
I thought I'd hang onto it for this very purpose.
I'm gonna pop it back onto auto focus and
just balancing it on my knee just to take a
close-up picture of a coke can.
You see even a crushed up coke can becomes pretty interesting.
Let's just go back to our old mate,
the zoom again. I've got one here, now this is
probably a bit more of a specialist zoom lens, this is a wopper as you can see
and it is really the domain of the sports photographer or wild life
photographer who's going to need a lens quite as big as this.
it's just the same as the zoom lens I showed you at the beginning
now you adjust the power of the zoom, the focal length by twisting this ring here.
This one goes to a 150 to a 500 millimeters
and you can manually adjust the focus by
twiddling the ring at the back. Now this is a very very powerful zoom so it
magnifies a lot.
There's a couple of ferries out over there and as you can see their really
quite small in the distance, now if I zoom in on them, this ones so powerful
I don't need a full zoom to fill the frame with
ferry, there we go.
As you can see I can make that big in the picture.
Now focal lengths are all very good for making far of things come closer but
there's actually a lot more you can do by adjusting your focal length:
than magnify stuff.