How Changing Aperture affects Depth of Field

Although I have many titles I am of course, a mommy first and foremost. The addition of my baby daughter in late April has mean’t that I have to be very creative in trying to make time to work, blog not to mention spending some fun time with my other little girl Sophie. So last Saturday I decided to roll these three things into one. We made these delish cupcakes and Sophie decorated them. She was very proud of her work, as you can see, spending 15 minutes decorating and 2 minutes devouring them!

Meanwhile I seized the opportunity to put together this mini tutorial for you on How Changing Aperture affects Depth of Field.

A lot of my students bemoan the fact that there is too much math involved in photography. And they are right – there is a lot of math!
If you get down to it, it’s all about math and physics but where would the fun be in learning about that? What about the creativity of manipulating light and dark? Evoking emotion in your viewer. Perfecting your art?

So let’s get visual and forget about the math for a minute.  What I want to demonstrate here is how I can alter the Depth of Field by Changing Aperture settings on my camera.

Depth of field refers to the zone of acceptable sharpness in a photo.

I took the following pictures of Sophie’s cute cupcakes in succession, everything(ISO and Shutter Speed) else been held constant, just changing the aperture of each shot.

You can see how increasing your f number (aperture) REDUCES the size of the opening in the lens  and hence increases the depth of field – the amount of the “in focus portion” of the picture.

Your Turn!

Try this at home by lining up several similar objects – wine bottles, tomatoes, flowers, crayons – whatever you have easy access to.

• In order to make this as easy as possible for you make sure your in a well lit place
• Set your camera to Aperture Priority mode- Usually either A or Av on your Mode Dial.
• Keep your focus point set to the same point each time. In the above pictures I kept focused on the orange cupcake.
• Turn the mode dial wheel of your camera to adjust the aperture values.
• Take a shot at every aperture value or f/stop that your lens will allow.
• Pay attention to what happens to the shutter speed values as you change your aperture.
• Upload to your computer and view the images side by side. This will be much easier than trying to use your camera LCD screen to view the images.

Can you see the difference between shooting wide open with a low f/stop and shooting with a narrow aperture and a high f stop?

There is a lot more to depth of field and aperture than just this including concepts such as “The circle of confusion” – Ha! but I think we’ll stop there for now.  If you get the above you’re doing good!

I’d love to see some of your shots so feel free to post them on the CameraShy Facebook Fan Page.

Happy Snapping!