Aperture – part 2: It’s all about depth of field

So you’ve promised to only use aperture priority and have been practicing day and night? J Then you’ll have noticed that your depth of field is also affected by something other than the size of the opening on your camera. Have you guessed it?

Distance from subject

Your distance from your subject also has a dramatic effect on the depth of field – the closer you are to your subject, the shallower the depth of field. Why? Well it’s all about converging angles – translation – you don’t need to worry, although if you want to find out more it’s just a google away.
So let’s add that to the rule we established in the last post:

The smaller the number and the closer you are to the subject,
the shorter the depth of field.

 

and of course the reverse is true:

The larger the number and the further you are from the subject,
the longer the depth of field.

Aperture numbers

You’ll remember from the last post that setting the aperture involves choosing a number, such as 5.6 or 8. These numbers are know as f-stops and one ‘stop’ will increase / decrease the amount of light entering the camera by 2 or ½ respectively; which will also affect the shutter speed you can achieve. We’re not going to go into the theory right now, but just remember that when we say ‘f-stop’ or show a number such as f5.6, we’re referring to the aperture number.

But why does it matter?

I can hear you screaming ‘but why does it matter?’ at this point, so let’s look at some real world examples.

When shooting landscapes, you generally want lots / all the scene in focus, so pick a high number for your aperture – anything from f8 – f16.


With macro, you want very little in focus to blur the background and concentrate on the details. Get close to your subject and use a low aperture, from f1.4 – f4.


For portraiture, you’re generally looking at the middle of the scale. If you’re in the studio with a backdrop, the ‘magic’ f-stop is f8 to get all your subject in focus. If you’re outdoors, put your subject away from the background and shoot in the f5.6 range to get the subject in focus and the background blurred. And of course, getting closer to your subject will shorten that depth of field even more.

Get to it!

 

So there you have it – switch to aperture priority and start practicing. There’s no better way to understand aperture than seeing the results!


Provided by Danny T Photography.