Understanding Aperture

What is Aperture?

  • Aperture is about the AMOUNT, the amount of light that enters your camera through the lens “hole” or the “eye” of the camera.
  • Once the light enters the hole opening in the lens, it then enters your camer

What is the Aperture on your camera?

  • Just like the pupil in our eyes that open and close depending on the amount of light we see, the camera has an eye too, which is the Aperture.
  • When our eyes need more light, the pupil opens up (creates  a bigger opening) to let in more light.  When there is too much light, the pupil gets smaller (creates a smaller opening) to let in less light.
  • So, the Aperture does the exact same thing for the camera, but the Aperture  “hole” opening lies within your lens.
 aperture

(LEFT)  f/1.4, the opening is big, lets a lot of light through (MIDDLE) f/5.6 , (RIGHT)f/16- the opening is small, lets less light through.

How is Aperture measured?

  • Aperture is measured in the size of the “hole” opening in the lens
  • Aperture is measured in a measurement called “f-stops”
  • The size of the aperture hole opening determines the f-stop number
  • The BIGGER the aperture hole opening, the MORE light comes in, which gives a SMALLER f-stop number.
    • The smaller f-stop numbers (such as 1.4, 2.8) let more light into the camera, and these numbers are considered “FAST”
    • So when you hear of terms like “fast lens”, “fast aperture”, “fast f-stop”, just know that means the lens is able to open up WIDE and letting more light coming in.
    • More confusing terms you will hear when describing the big hole opening: “Stop down your f-stop”, “wide aperture”, “open up your f-stop”. All that means is to let more light into the camera by opening up the aperture hole opening, which you do by making the number smaller.
  • The SMALLER the aperture hole opening, the LESS light comes in, which gives a BIGGER f-stop number
    • The bigger f-stop numbers (such as 6 or bigger) let less light into the camera, and these numbers are considered “SLOW”
    • So when you hear of terms like “slow lens”, “slow aperture”, “slow f-stop”, just know that means the lens hole is SMALLER and give you less light coming in.
    • More confusing terms you will hear when describing the smaller hole opening” “Stop up your f-stop”, “small aperture”, ” close your f-stop”. All that means is to let less light into the camera by closing up the aperture hole opening, which you do by making the number bigger.

aperture

Wait! This is confusing! Big opening, why smaller f-stop number? Small opening, why big f-stop number? Why is it opposite?

 

  • Right! This is why everyone gets so confused and frustrated about understanding aperture!
  • It makes sense that the bigger the Aperture opening, the more light comes in, but why is the f-stop number smaller?
  • And, it makes sense that the smaller Aperture opening, the less light comes in, but why is the f-stop number bigger?
  • Answer- The bastards who set it only wanted to confuse everyone! Just kidding,  it is actually in reference to the lens’ focal ratio, but we won’t get into it further because it will make your head spin.  For now it may be more helpful to understand what the numbers do with the following little analogy:
  • Try understanding the f-stop number relationship this way:
    • Imagine your windows as the aperture on your camera (stand in front of your windows if this exercise helps), with the drapes hanging.
    • Pull all the drapes to the edges, more light comes in, right? So you just opened up the aperture “hole” opening, by letting in more light. Imagine the small f-stop number as the amount of drapes that is covering the hole.
    • So, you have LESS drapes covering the light coming in, the less drapes equals the SMALLER f-stop NUMBER!
    • More light comes in= less drapes covering the window = smaller f-stop number.
    • Exercise again: Pull more drapes in, covering more of the window, which means less light comes in.
    • So, you have MORE drapes covering the window, the more drapes equals the BIGGER f-stop NUMBER!
    • Less light comes in = more drapes covering the window = bigger f-stop number.
    • Finally, imagine the f-stop number as the amount of coverage, covering up the light opening.

How to control Aperture?

Just like controlling the amount of light into your room by opening and closing the window shutters, you can control your Aperture and how much light enters your lens, then to your camera. Essentially controlling your Aperture is one part of controlling your total Exposure

  • Most camera’s will have a “Aperture Priority” function on your camera. You can choose your Aperture  and make it fast or slow by turning the dial. Your camera will automatically adjust the rest of the exposure settings.
  • You can control it on “Manual”, but this will take more practice because you will have to manually control the rest of the exposure components (Shutter Speed and ISO).

Why would I want to understand Aperture? Isn’t it easier to just shoot on “auto” or “program” and let the camera do it all the thinking for me?

  • Certainly on most occasions, letting the camera do all the thinking for you will give you good results.
  • BUT, in order to take your photography to a higher level and more CREATIVE CONTROL, you must learn Aperture.

OK, so what exactly does this Aperture thing-y do? How will it give me more choices and creative control? – Answer: DEPTH of FIELD

  • The primary creative control of Aperture is to control the “Depth of Field”, which means how much of the image you want to be in focus.
  • By controlling the amount of light coming into the camera by the size of the Aperture hole opening, you control how much FOCUS you want.
  • When you’re photographing  something with a NARROW or SHALLOW depth of field, that simply means that you want something specific to be in focus (only one part) and the rest to be kinda blurry.
  • When you’re photographing something with a WIDE or DEEP  depth of field, that simply means that you want more of the picture to be in focus.

EXAMPLES of Aperture controlling your Depth of Field- how much you want to be in focus:

apertureThe tomato picture has very NARROW or SHALLOW depth of field because only a specific, selected point is in focus, where as the rest of the image is blurry.

Foreground: the single tomato and the wood in the very front of the image is sharp, in focus.

Midground: the cluster of tomatoes is less in focus, kinda blurry

Background: the tomato leaf, and basket of tomatoes is very blurry, out of focus.

This was shot intentionally so that the focus would be on the single tomato, bringing the perspective to the single tomato. Still pretty, isn’t it?