What is Aperture (f-stop number) in DSLR camera

what is Aperture?
Aperture is nothing but a hole. In camera, it is the opening that controls the light rays to fall on the film(sensor). It is measured in terms of f-stop numbers.
It is calculated as f-stop number = focal length of lens / diameter of hole.
It is denoted as f/2.8 , f/4,.....
In general, we have following f-stop numbers  f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22.
Lesser is the number like f/2.8, less will be the area in focus and vice-versa. So while taking a picture say a flower, choosing a smaller f-number will give an effect where only flower is sharp and background is blur. And when you wish to take a picture of whole garden then choose a large f-number so that everything is in focus.

Suggested exercise: Depending on lighting conditions choose a shutter speed and keep it constant (say 1/200). Now try clicking pics by changing only f-stop number each time. Make sure you don't change the subject(say flower) you are shooting!

You will notice two important things,

  • With increasing f-stop number the picture is getting darker which means in low light conditions one can lower f-stop number and in bright day light one can have high f-stop number.
  • The area which is in focus(sharp) increases with increase in f-stop number.

Video credits Lori Allen

Comments

Post a Comment

Popular posts from this blog

How camera works?

Image
To know this, lets look at all the parts that a camera has in it. Following figure briefly shows how light passes through different parts of camera. It is an SLR camera which is the most common and traditional equipment used in photography. Image credits Black Pearl The light reflected from a object passes through a set of lenses, and onto a hinged mirror. From there it is reflected to a five sided prism called Pentaprism in such a way that what ever you see through the eye piece is exactly the same light falling onto film. The click button flips the mirror. While looking through the eye piece, the mirror is in inclined position(as shown) and as soon as one presses the click button the mirror just moves upwards so that all light falls on film and therefore the image is captured. Video credits Allversity
Keep reading

What is photography

Image
Photography is an art of capturing moments in a frame. An object is seen when light falls on it and is reflected back to our eye, everything that can be seen in this world is only because of light. So in order to take a picture of an object, one has to capture light reflected from that object. When we talk about photography, we actually talk about light and different ways to capture it. A little knowledge about light and its properties is necessary to understand photography. Video credits Joe Edelman Importance of Lighting in Photography Light: It is a spectrum of electromagnetic waves. Human eye can observe only a part of the light whose frequency is between 400nm to 780nm(approx.). So in photography all the light we see fall into this frequency range. Things to remember: Light travels in straight lines. Intensity of light decreases by square of the distance. Following video explains how inverse square law applies to photography Video credits Gil
Keep reading

Which Camera to buy?

I classify cameras into three types: Point and shoot cameras Bridge Camera Professional Camera As the name says "point and shoot" camera is for those situations where one has to point the camera to the object and just click. Almost all the compact digital cameras fall into this category. They are designed and automated such a way that everything is done in one click. Suggested for everyone, even to those who want to be a professional photographer because it very compact, easy to handle and quick.            Pros: Automatic features, Portability, Compact and Quick.          Cons: Very few manual options                                                                            Bridge Camera: It is a bridge between full automatic and total manual camera. It carries all the technology from point and click camera and adds some more manual features to it making it more versatile and good starter kit for enthusiastic learners.They tend to have more zoom capability as
Keep reading