You know those pictures where only the flower is in focus, and everything else is blurry? Or the pictures where only the pen on the white paper is focused and the rest isn't? (yes I agree, that's a very bad example.)
So what about the picture where only the bride and groom's faces are nicely focused, and the rest of the world doesn't exist? Now that's more like it.
Before we start, let's have a look at 2 quick examples.
As you can see in the two examples above, only a specific subject in the two pictures is in focus, whereas the rest of the picture isn't in focus.
We're now going to understand how to achieve this effect easily.
First, we will try and understand what aperture is. Wikipedia tells us "An aperture is a hole or an opening through which light is admitted." Ok, great. Thanks for that info. It was really helpful.
Just kidding, there's a lot more to that quote, but it's not Wikipedia here.
We will try to understand what aperture is by using simple language and some basic terms.
The aperture controls the amount of light that enters your camera. The lower the aperture number is (1.4,2,2.8 and so on), the bigger the hole where the light comes in is, and therefore more light comes in. The bigger the number (11,16,22 and so on) the smaller the hole is, and therefore less light comes in. The numbers mentioned above are called F numbers and their purpose is to let us know how big or small our aperture is. The diagram below explains quite simply what I'm talking about.
After understanding the mechanics of the aperture, let's have a look at the things the aperture affects:
1. The amount of light:
As you already know, the aperture's size affect's the amount of light that goes through your lens and onto the camera's sensor. Let's just go over it once again-
A small F number means a bigger hole which means we get more light in.
A big F number means a smaller hole, which means we get less light in.
2. Depth of field:
I'm sure you've heard that expression before, but I'm not sure you understood exactly what it meant. I'm not sure I do either.
What I do understand is that by altering the aperture setting on your camera (higher or lower number) you change the depth of field of your picture.
That said, let me share my great knowledge with you.
Let's take the picture of the rose as an example. You might want to click on it to get a better look before we start.
As you can see, only the red rose is focused. This means the depth of field (known sometimes as DOF), is short. How do you achieve this effect then? You set the aperture to a small number, set the right shutter speed or use the aperture priority mode (don't forget to read about shutter and modes here), and take the picture. See the picture below as another example.
*Note that the DOF is changed not only by the aperture (large or small), but also by the distance to the object, and the lens you are using.
The equation is like this-
large aperture (smaller opening), results in a wider depth of field.
Small aperture (bigger opening), results in a lower depth of field.
Let's take a different example now. I'm sure sometimes you want to take a picture of a nice landscape. Landscape pictures have areas which are closer to the camera and areas which are much farther away. (The grass near you, the trees far away, and the sky way above). Ok, so let's think this through together. We know that by setting a small F number, only a certain part of the picture is sharp and focused, and that by setting a large F number, we get a larger amount of sharp areas. So what f number should you use for this kind of picture? A high f number. Get it?
And the last example will be the one when all you want to do is aim and shoot. People are standing about 3 meters away from you and behind them is a beautiful view. You want the people to come out nice and sharp, and the background behind them quite sharp as well. What aperture (f number) should you use? Think about the answer for a second before continuing.
The answer is- you set the f number in the middle. Between 8 and 11 will usually do the job.
3.Sharpness:
We covered this point in the previous topic, but just to make sure we understand it we'll go through it quickly again.
The sharpness is the area of the picture which is in focus. A landscape picture is usually sharp throughout the whole picture. A portrait picture is usually sharp only where the object is standing. An artistic photo has no rules.
Aperture
by Amigo | 23:14 in aperture, depth of field, f stop, focus, lens, sharpness | comments (2)
How many time have you heard a variation of this sentence?
'I want to start taking great photos like professionals do.
I heard something about a Nikon D80 being quite good camera, or a Cannon EOS 50D. Which one do you recommend I get?'
My answer is usually something like this- 'I think a Fugifilm will do just fine.'
It has almost become a fact. When someone want to start learning something new, he has to have the best, newest, most expensive equipment, or else it won't be fun or worth the effort.
How many times have you seeing someone buy a new set of golf clubs, use it once or twice, and since then it's sitting nicely beside the vacuum cleaner in the garage?
I have to admit I never saw anyone like that.
So I'll try to give a better example:
Someone says to himself- I've got to get back into shape. I'll start by running 3 KM a day, and I'll slowly move on to 6, 9, and then maybe 12 KM a day. Well I guess I've got to get my self some good running shoes. So off he goes to his favorite sports store, and tells his great plan to the very helpful sales guy who knows exactly what our guy needs. A pair of the amazing Saucony shoes which are lighter than any other shoe in the market, they are made out of this wonderful new fabric which will never get damaged, no matter what you do to them* (*except if the get wet, burned, cut or left out in the sun), and of course they are great for the distances our guy is planning to run.
There are one or two other choices, Brooks and Asics have great models as well. Want to have a look?
Surprising, that same old guy of ours, has just found interest in a site called eBay. He heard it's a great place to sell second hand or used products.
Look, what I'm trying to say is, you don't always have to get the best most expensive product. Sometimes getting it will only have bad results.
Imagine someone who during his whole life has being using a PC, and then suddenly his parents decided to get him a MAC for his birthday. Poor guy, he won't understand how to turn the thing on. And if he does finally find a way, he will have a very hard time understanding why the machine keep's working for more than 20 minutes without getting stuck or having to press the restart button.
Ok sorry about that. Let's be serious again.
Someone once told me- 'You don't have to be Neil Armstrong to understand how to ride a bike'.
Same thing when we're talking about cameras and photo shooting. You don't have to have the newest Cannon or Nikon in order to shoot great pictures. All you need is nice a nice composite, a basic camera with the option for manual settings, and good imagination.
During our time together, I'll try to explain more about what I mean, and I'll give you tips about how to achieve what I'm talking about.
For all the beginners out there (and it not something bad to be a beginner! on the contrary!),
I'll try to explain all there is to know about cameras, shooting modes, setting, and what it takes to take the best photos without having to buy a new set of golf clubs or a pair of new Brooks.
Imagine this-
You are 32 years old, you have 2 kids. The younger son is outside with his friends playing football. It's a nice sunny day so you decide you're going to join the boy. Oh no I don't mean play with him, all you want to do is go outside and make sure you have some pictures of the occasion.
After putting on your favorite T-shirt, you walk outside and sit down on the bench (don't worry we're just about to get to the point). You take the camera out of it's case, and wait for the perfect moment.
And their it is! He has the ball! His just about to kick the ball!! Wow that looks great! Click. You took the picture. Now it's time to have a look at it.
If someone was watching you at that moment, they'd think your mother in law just had a heart attack.
The picture is completely smeared, and not only that, it's way too bright!
Ok. That was a quick introduction to what's called shutter. As you can learn from the intoduction, the shutter can effects both the amount of light and the way object's appear smeared or not.
Before going into example of each one of the cases, let's first have a look at some technical info about the shutter.
"A shutter is a device that allows light to pass for a determined period of time, for the purpose of exposing photographic film or a light-sensitive electronic sensor to light to capture a permanent image of a scene." That's from Wikipedia.
If we try to translate that into easier language we could say that, the shutter is basically what controls the amount of time our camera's sensor, is exposed to the light coming threw the lens. Again, the light coming from the outside goes threw our cameras lens, then threw the hole (aperture) we set, and eventually it reaches the shutter. The shutter can be either opened or closed. Theirs no in between point. You can see an example of what a shutter looks like on the left.
How does the shutter thing work?
It's simple. We tell the camera how much time we want the shutter to be open for, and the camera does exactly what we tell it to do. I wish everything was that simple in life. We can tell the camera to open the shutter for a very long time or for an extremely short time.
What should you tell it to do then? Why should you care about how long the shutter is open for? All you want to do is take a good looking picture.
And that's exactly my point. You want a good looking picture.
As we've learned, the shutter controls both the amount of light, and if our objects are smeared all over the place or not. It does this by the speed the shutter opens and closes. It can open and close really quickly, or open and the close after a longer period of time.
The light:
The slower the shutter speed is, the more light reaches the sensor.
The faster the shutter speed is, the less light reaches the sensor.
So if it's still 14:00 and your son is still out their with his friends, the light coming from the sun is probably quite strong. So you will want to use a fast shutter speed, because the light outside is so strong that even by opening the shutter for 1/500 of a second, enough light will reach the sensor.
On the other hand, if the time is 18:30, and the sun is just about to set, the light isn't as strong. In this case you will need to have the shutter open for longer (1/60 for example) if you want the picture to be nice and bright.
But if the object you're photographing is moving (like your son kicking the ball), he will probably come out smeared using a slow shutter speed. We'll soon understand why that is.
Let's take a look at an example of to different shutter speeds:
Shutter speed (Motion, and Smear):
The shutter can open and close either quickly or slowly.
The faster the shutter opens and closes, the less motion and smear will appear. (Freeze effect)
The slower the shutter opens and closes, the more motion and smear will appear. (Motion effect)
Now this is where it becomes fun. We'll use a race car as an example.
What will happen if you take a photo using a slow shutter speed (using a tripod)? The car which is moving fast, will come out kind of smeared, and it will add an effect of motion. Why? Because the camera's sensor will be exposed for a longer time, and as the car moves along, the sensor captures the movement. The background around the car, will come out nice and sharp because it stayed still.
So what will happen if we use a really short shutter speed? The sensor will be exposed for a really short time, so the car's movement will be captured to a frizzed looking photo.
The fun part is when you start adjusting the shutter to different speed's and see the exciting results.
Exposure (in short):
The shutter speed effect how bright or dark our picture will be. We know the same thing is true for the size of the aperture.
So if we want to take a picture of the car moving without the motion effect, we will have to use a really quick shutter speed, and that will cause less light to reach the sensor, and then we could have a really dark photo. To fix that you'll have to use a very low F-number (wide aperture) in order for more light to enter the picture. If that is not enough, you can play with the ISO.
In short, the exposure and the shutter work together when effecting the exposure. (More about exposure here)