Tips / People Inside Your Camera /
4 - Ms. Lens Opening
Ms. Lens Opening makes a circle become smaller and larger in
the lens.
This circle is like the iris in your eyes.
The circle is called the lens opening, the f/stop,
or the aperture.
 |
| Ms. Lens Opening |
| f/4, f/5.6, f/8, f/11, f/16,
f/22 |
Ms. Lens Opening Speed speaks "words" like these: f/4, f/5.6,
f/8, f/11, f/16, and f/22.
The words are called apertures, f/stops, or lens openings.
BTW—your camera probably has more apertures than those above.
Aperture is another way you can control how much light reaches
the sensor.
The aperture is inside the lens.
The aperture works like the iris in your eye.
When your retina (sensor) needs more light because it's night,
your pupil (aperture) opens up.
When your retina (sensor) needs less light because it's night,
your pupil (aperture) closes down.
| x |
f/4 |
| x |
f/5.6 |
| x |
f/8 |
| x |
f/11 |
| x |
f/16 |
| x |
f/22 |
Extra Benefit from Ms. Lens Opening
Let's say you're photographing a 1940s Fiesta Ware sugar bowl.
When you camera focuses on the bowl, it's in focus.
But, part of the space in front of the bowl may also in acceptable
focus.
And, part of the space behind the bowl may also in acceptable
focus.
These areas of acceptable focus are called the depth-of-field.
Blur the background with Ms. Lens Opening if:
• If the background is distracting.
• If you want the subject to stand out from the background.
Set the aperture so there's less depth-of-field.
Use a physically large aperture, which has a small number, such
as f/4.
| picture here |
| f/4 - Less Depth-of-field |
If the background adds to subject, try to make it sharper.
Set the aperture so there's more depth-of-field.
Use a physically small aperture, which has a large number, such
as f/16.
| picture here |
| f/16 - More Depth-of-field |
As mentioned, your camera has apertures in-between those above.
In-between Lens Openings
Your camera has lens opening in-between those above.
Check your instruction manual.
How Do You Set the Lens Opening?
You can set the lens opening several ways.
Exposure Mode Dial
You may have an exposure mode dial on your camera.
Look for A or Av.
That's the lens opening setting.
Usually, you can adjust the lens opening by turning a knob near
your thumb or forefinger, as you hold the camera.
If there are two knobs, try one or the other.
ASM Button
If there's no exposure mode dial, look for the ASM button.
Pressing the ASM button will cycle the camera to A.
That's the lens opening setting.
Usually, you can adjust the lens opening by turning a knob near
your thumb or forefinger, as you hold the camera.
Don't Have the Above?
Don't have an ASM button?
Check your instruction manual.
Somewhere on the menu you'll find lens opening.
Remember, lens opening is also called f/stop and aperture.
Hi & Lo
Hi or Lo may appear in the viewfinder or on the LCD screen.
Hi will appear when there's too much light.
You have to choose a faster lens opening.
Memory Device
The bigger the number, the less light is reaching
the sensor.
The above mnemonic can help you to understand what's happening
as you change the lens opening.
For example, the lens opening f/16 is a bigger number
than the lens opening f/11.
So, at a lens opening of f/16, less light is reaching the sensor,
than at f/11.
Next, let's look at Mr. ISO.
