I’m going to take you to a
natural example which will itself show you the science behind the this
mechanism. Before discussing what is aperture, I would like to tell the substitutes of aperture. The other name of aperture is very familiar to every photographer
as well as the gear, is F-Number and found (f/) as symbol in any DSLR (Digital
Single Lens Reflex). Bokeh is another name of aperture. Actually it’s the
blurriness of a background. Let’s talk about what this thing is and how it works.
How To Control Aperture in DSLR (Digital Single Lens Reflex)
I was talking about a natural
example to explain aperture, which is a “human eye”. The camera’s aperture
functions same as our eye does. Let me put here a very simple example. If you bring
your finger in front of your eye very close and try to focus on your finger,
you’ll see that the background behind your finger gets blurred or gets out of
focus. Depth of field (DOF) depends on the focal length of our eye. If
the finger is far from the eye then the background behind the finger will be
less blurred or the finger will be more in focus and when the finger will be
close to the eye then the background will be more blurred or gets out of focus.
There are many metering modes of aperture or F-Number in a DSLR. Typically
F-Number starts with 1.4 which is desirable for every photographer. Heading
towards the higher F-Number, which is 1.8, 2.0, 2.8, 3.5, 4 & 4.5
respectively in prime and telephoto lenses. The less the F-Number is, the more
the background will blur. The higher the F-Number is, the less the background
will blur. To elaborate this difficult mechanism, here’re some of the simple example
pictures to learn you more quickly.
If we increase this figure from
f/1.8 to 32, you will achieve less blurry background while decreasing the
F-number will result the smooth background. Aperture or F-Number is technically
a mechanism in every lens to control the blurriness of background. In a DSLR, you
can control it manually in Manual Mode or setting the Mode Dial
on Aperture Mode (Nikon) or AV Mode (Canon). In Nikon,
you can find a button right behind the shutter release button. Mechanically, it
consists of 5 or 6 blades which closes or discloses the way that goes to the
sensor of a camera. If we set a camera’s F-Number to a minimum of f/1.4 then
the blades will be fully opened to focus the subject very clearly, while in
this situation as we set the f/1.4 the background will be much smooth. Higher
F-Number can only be used in intense light conditions because increasing this
function suppresses the pathway to the sensor that’s why light has less chance
to meet the sensor. Most of the photographers increase F-Number in order to
shoot landscapes and use wide-angle lens to cover the whole scenario. While
telephoto lenses starts with an extended focal length that’s why they don’t
have the ability to capture the landscapes in wide angle.