So What Is Aperture Value ?
So what is aperture value? It’s the opening in a camera lens.
The aperture value along with shutter speed and ISO work together when taking a photograph.
They control taking the photo and what it will look like regarding the colour, brightness, sharpness, and focus.
When you press the shutter release to take a photograph you open a mechanism in the lens which lets light in.
That mechanism is the aperture.
The light that does come in is that which is reflected from the scene which is in front of the lens at the time.
The image in this scene is recorded onto film in a film camera, or a sensor in a digital camera.
The aperture opens briefly in the lens to let in the reflected light which results in the image.
You can adjust the aperture to open to a greater or lesser degree.
This helps to produce a different quality of photograph in conjunction with ISO and shutter speed.
The length the aperture remains open for is governed by the shutter speed.
Aperture values to explain what is aperture
The aperture settings on a camera are shown as numbers preceded by an f such as f1.8, f3.5, f6.3, f11 and f16.
This is just a sample of the f numbers available.
Generally the range of aperture values in common use starts at f1.2 and rarely goes beyond f32.
The f numbers govern how wide the aperture opens when you press the shutter release button.
The lower the f number the more the of the aperture opens.
The higher the f number, the less it opens.
Therefore at f1.8 more of the aperture opens than at f6.3. While at f6.3 it opens wider than at f11 and so on.
That’s a very basic explanation of what is aperture and the mechanics involved.
It’s what it does to the photographs that’s is the important thing.
The wider it opens, the smaller the portion of the photograph that is in focus.
When it opens less, more of the photograph is in focus.
The difference between one f number and the next in the sequence will make little difference to the photos sharpness.
This means that no single f number is vital to the quality of a photograph in terms of how sharp it will be.
Examples to show what is aperture
The best way to see what is aperture is to look as some photographs that illustrate it.
I took a series of photographs at different aperture values.
The subjects are the same in all of them, some toy dinosaurs, part of a guitar and some oranges.
In the first group of photographs I set the aperture to f1.8.
At this value there’s a very limited depth of field.
This means that there’s only a very small portion of the image in complete focus.
The faces of the brown dinosaur on the left is in focus.
So also is the face of the green dinosaur second form right.
The rest of the image is out of focus.
The focus in the guitar phots is very close to the front, and only this small area is in focus.
In the orange photos it’s right at the front, where the photo is sharp
More sample photographs
I shot the second group of photographs with an aperture value of f3.5.
This didn’t open the aperture as wide as f1.8 did, so the depth of field is slightly greater.
There’s a little more of these photos in focus then.
Most of the orange dinosaur at the front is in focus, but not it’s face.
The blue dinosaur at the back is still totally out of focus.
It’s a similar story with the photos of the guitar and the oranges, a slightly greater depth of field.
The next aperture value I shot a series of photos at was f6.3.
At this aperture value, the dinosaur photo is almost in complete focus.
The back of the blue dinosaur is all that isn’t.
These are small toys which I placed with only 10 or 12 inches from front to back of the subject.
As the number of the aperture value gets bigger, less of the aperture is opening.
That focuses things better and more of the image gets sharpened.
While f11 is not considered the sharpest aperture value to shoot at, most of the photograph is in focus.
The blue dinosaur’s tail is slightly out of focus.
The focus point of the dinosaur photos was set farther back than in the others.
For that reason there’s less of the guitar and oranges photos sharp at this aperture value.
Setting the focus 1/3 into the scene is the best place to get sharpness throughout.
The last sample photographs
As the aperture gets smaller, the f numbers get bigger the difference in sharpness of photographs lessens.
The last photos in the series are at f11 and f16.
f16 aperture value is a favourite for landscape photographers, because it has a huge depth of field.
At these f values the dinosaur photograph is almost totally sharp.
If you keep the camera steady or use a tripod you should get a totally sharp photograph.
The photograph of the oranges looks almost sharp throughout also, but the guitar doesn’t.
That’s because there was some distance between the camera and the oranges and there was none between guitar and camera.
Learning what is aperture value and what affect in particular it has on a photograph will help your photography.
It will allow you to take a photo that’s sharp through, or to isolate a particular focused object.
Check out these articles
This is my explanation of what aperture is and what it does.
Check out some other articles on the subject to get take on it.
You may find their presentation easier to understand than mine, or will add a better understanding with mine.
Read about shutter speed which works in tandem with aperture and ISO.
Find out more about aperture in the articles Introduction to Aperture in Photography and BACK TO BASICS – APERTURE.
