DOF (Depth of Field)
As the name suggests, DOF means the amount of sharp portion (Sharp field of view) when looking thru your camera's viewfinder, before or behind the focussed subject. The DOF is controlled by the Aperture of the Camera.
There are many types of camera in the market, but, every camera has got the Aperture, the one like KODAK KB10 (Compact Camera), has a fixed Aperture (which the user can't change). A Camera like NIKON FM10 (Professional in layman's terms or SLR Camera), has a dedicated ring, rotating which sets the Aperture, so here the User has the option to select his/her choice of Aperture.
Aperture, as the Name suggests is the small opening through which the light enters before falling on the Film/Sensor (Sensor in case of Digital Cameras)
As a rule:
Smaller the Aperture size, higher the DOF (means more amount of Field of View is Sharpened). And similarly, Bigger the Aperture, lower the DOF (means less amount of Field of View is Sharpened).
The convention:
The aperture is denoted by the f-stops as something like this as simple numbers (The following is of one of the Nikkor Lenses, these variations at the extremeties, could vary with varying Lenses):
22 16 11 8 5.6 3.5
Now the main convention followed is:
Higher the Value of the f-stop, lesser is the Apperture size.
As can be seen Above, f22 has the smallest Aperture opening, and f5.6 has the largest.
The Challange:
For Any Photographer, the real challange is to select the right aperture before clicking the shot. For example, f16 or higher means everything in the picture (literally) would be sharp, so, it's advisable to select higher f-stops (f11, f16, f22) for Landscapes (f11 is usually suggested, as anything higher does purple fringing, contributed by stray Ultra Violet Rays)
Similarly for Macro Photography (Closing in to the subject and shooting), blurring out the background makes a good sense, as the subject that close will show lot of details, so, it's good to focus the thing we want to show the most. So, it's advisable to select lower f-stops (f1.8, f3.4, f5.6) for Macros.
Please note that, as we go nearer to any object, it's background gets blurred.
4 comments:
Great post...
Maybe, you can put the it this way:
"Depth of Field (DOF) is that amount of your shot that will be in focus."
And then:
"Large depth of field means that most of your image will be in focus."
And, well:
"Small (or shallow) depth of field means that only part of the image will be in focus and the rest will be fuzzy."
It's just me, but this could make the picture clear for a wider audience.
Great going so far.
hey Amit, that's a really nice suggestion. Will update the post soon. :)
Thanx guru. :)
how about for action? what do u suggest?
great info :)
hey elaine, you mean Action Photography? Well will soon put that too. I guess, there i can tell something on ISO too.
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