I must start today's photography tips post with a confession: I find the technical details of how a camera works incredibly boring.  I have learnt what I know through a combination of endless trial-and-error, painfully long-winded research, Googling and discussion with other photographers.  I would never claim that I know everything.  Or even anything very much.  But I know what I didn't know before.  If you know what I mean!  

When I started out in photography, terms such as aperture, f/stop, ISO and shutter speed were a mystery.  I got incredibly frustrated, trying to read photography blogs that I just didn't understand.  I'm hoping that these photography tips posts might help others in a similar situation by explaining the early basics of photography, the stuff you need to know in order to start experimenting with your DSLR manual mode.

Learning about aperture was a bit of a revelation, actually.  Knowing how to use it gives you a lot of control over the final appearance of your photos.  So, here are the basic things you need to know about aperture:

1. F/stop bigger, aperture smaller

The aperture is the hole in your camera lens that allows light in.  We talk about the size of an aperture in terms of f/stops.  The most confusing things about aperture is that, when talking about aperture size, the higher the numbers go, the smaller the hole!  So an aperture of, say, f/1.4 means that the hole letting light in is much bigger than if you set your aperture to something like f/16. Totally counter-intuitive! 

2. Depth of field - shallow

Photographers often talk about how to achieve the perfect 'depth of field' and the aperture helps to control this.  'Depth of field' means how much of your image is in focus.  If you have a shallow depth of field, only a small plane of your photo is focused and everything else around (both in front of and behind the focus point) gets increasingly less focused as it moves away from the focus point.  

When the aperture is large, the depth of field is very shallow.  In these two photos, above, the aperture was set to f/2.0.  Remember, this means that the hole is large (because the number is small.  Gaaaah!), allowing a lot of light into the camera.   In the image on the right, only Daniel's eyes are in focus, making them really stand out.  I chose a larger aperture for the one on the left as well because when the hand (or anything in the foreground) is out of focus, you get a better sense of the visual distance between the hand and the face, giving the image a bit more depth.  

However, having a very shallow depth of field can make an image look a bit distorted, by enhancing one feature. If Daniel had a very big nose, the image on the right would make it stand out even more by increasing the sense of visual distance between his eyes and the end of his nose!  Luckily, he doesn't have a very big nose!

I like to do portrait photography with a larger aperture (anything from f/1.8-f/3.0 and I mainly use a prime 50mm lens, for those who are interested!).  It means that backgrounds are nicely blurred (that's the bokeh I was talking about in my last Photography tips post), features are softened and key elements such as beautiful eyes really stand out.  In the photos below, the first two are taken at f1.8 and the third one is f2.8.  

3. Depth of field - deep

If you are taking a group photo, you need to have a deeper depth of field, so that everyone is in focus.  For this family photo, below, I wanted everyone in focus but they are all sitting at different 'depths', so I upped my aperture size to f/4.8 (making the hole smaller and the depth of field deeper...is it starting to make sense, yet?!).  This is still quite a large aperture as I didn't want the background to be in perfect focus.  I would use a much smaller aperture (say, f/18) if I was photographing a landscape and wanted all the details in focus. 

DSC_0169.jpg

In this photo, below, my aperture size was f/3.5, but it would have been better if it was smaller (like an f/5-f/6) as the baby in the foreground is out of focus.  Had my depth of field been deeper, the baby would also have been in focus.  I still like this photo for the sweet, shared moment between the two women but if I had been quicker to change my aperture size, it would have been even better!

4. Balance

Photography is all about balancing how much light gets into your camera.  If you have a lot of light coming in through a large aperture (such as f/2.0), you will need to balance that with a quicker shutter speed, so less light comes in during the moment the photo is taken (shutter speed will be my next 'Photography tips' post).  If you are taking photos somewhere with not much natural light and you don't want to use a flash, you might want to use a wider aperture so that more light is allowed in that way.  Or you might make the shutter speed longer.  Both of these things have advantages and disadvantages, so you have to balance them to work out the best fit for the situation you're in.  

Summary

  • Aperture is the hole through which light gets into your camera (larger hole --> smaller f/stop number).  
  • A large aperture size (smaller f/stop number) will create a shallow depth of field and vice versa.  
  • You need to balance aperture size with shutter speed and ISO.

I hope that gives you a starting point.  Now, go experiment with manual mode!