14 Jul Understand how Aperture works in dslr photography
Basics of Photography
in this post we will discuss the Aperture and depth of field.The two terms are linked together in a sense aperture controls the depth of field in a picture. Depth of field refers to the amount of area which is in focus in your image.
Above image is a courtesy www.shariblog.com
Aperture is the hole in the lens of the camera that allows the light to enter the camera. It is referred in photography terms as f-stops. The f-stops can be 1.4,1.8,2,2.8,4,5.6 and so on. A smaller f-stop means bigger aperture (i.e bigger hole) and bigger f-stop means smaller aperture (i.e. small hole). As shown in the above image the aperture is related to depth of field in a image. A smaller f-stop means narrow depth of field and a bigger f-stop means more depth of field.
A lot of my friends ask me how to get the blurred background in the back of the subject?. The answer is smaller f-stop and narrow depth of field. The 50mm Nikon AFS f1.8G lens allows to shoot portraits and blur the backgrounds for my portraits.Its important to understand this since the smaller f-stop for eg. f1.8 is a larger whole it will allow more light into the camera also since the f-stop is smaller the depth of field would be narrow and larger f-stop lets say f16 would mean a smaller hole and less light will enter into the camera and the depth of field would be larger from foreground to background.
Image with smaller f-stop f1.8
As you can see the above image is shot with smaller f-stop and has the background all blurred.
Image with bigger f-stop f16
This image has a high f-stop of f16 and as you can see the depth of field is more, everything from foreground to background is in focus.
You can practice aperture by aligning set of pens or bottles on a table. Use the AV or A mode on your DSLR and then set your camera at the smallest f-stop by rotating the main dial ( for standar kit 18-55mm lens this is f3.5 usually). Focus on the nearest pen/bottles and check the depth of field. You should see that the remaining pen/bottles would be blurred. Now increase the f-stop bit by bit and you will see more pens come to focus. Practice this and let me know how it went.
For more tutorials about aperture and depth of field check the following references
Understanding Maximum Aperture Nikon USA Website
Understanding Aperture in 5 simple steps ExpertPhotography.com Website
Introduction to Aperture from digital-photography-school.com Website
Will be posting Basics of Photography Part 2 Soon