I have decided to write a few articles on the most basic aspects of photography, which will become natural as you start mastering this art. However, I remember struggling with them when I first started – and I guess that most of us have a similar experience.
Today, I am going to cover lens aperture, which is an incredibly important factor to ensure sharpness and being able to drive the viewer’s attention across the frame.
Apertures – Nikon.com
The aperture is the technical term to describe an opening of the lens diaphragm through which light travels. The aperture is represented in f-terms, where a smaller number represents a wider aperture – e.g. f1.4. On the other hand, the higher the f-stop, the smaller the aperture – e.g. f16. As you can imagine, when the aperture is wider, it allows more light to go through the lens, resulting in a brighter image. The minimum and maximum f-stops will depend on your lens. Most of the times the minimum aperture is f22, while the maximum can go down to f0.75!
Many lenses – especially older ones – show an aperture ring, which allows to manipulate the aperture from the lens directly. Very often, a similar process can be managed in camera too. By setting the camera modes on Aperture Priority or Manual Mode, you can change the f-stop manually. This would allow you to experiment and see how the image changes at different apertures.
How Does Aperture Impact on Depth of Field?
Aperture, DOF and Shutter Speed – Boredpanda.com
Depth of Field – DOF – is the area of acceptable focus before and behind the subject. When the aperture is wider, – e.g. f1.4 – it will create a much smaller DOF, resulting in less of the subject being in focus and a nice blurry background. This effect is called ‘bokeh’ and you will probably fall in love with it! On the other hand, when the aperture is smaller, – e.g. f22 – the DOF will be much larger, resulting in more sharpness front to back. The former aperture is optimal for nice and dreamy portraits. While the latter is an exceptional ally for landscape photographers.
If you have read the previous article of the series: ‘Photography Basics’, you will probably know that when there is less light available, you need to slow your shutter speed down. This means that as we increase the aperture number, we will need to decrease the shutter speed in order to maintain the same exposure.
Aperture in Street Photography
In street photography we care about being as responsive as possible in order to be ready to capture the decisive moment. This means that we should minimise any risks of taking unsharp pictures and processes that slow us down. As a result, most street photographers like to use an aperture between f5.6 and f11. Firstly, this will ensure the optimal sharpness performance that your lens can deliver. Secondly, it will decrease the risk of out of focus photographs – especially if you focus manually. Usually, I like to keep my aperture at f8.
However, you can also experiment with wider apertures to better separate your subject from the busy background and create some interesting bokeh. This technique is extremely powerful when photographing street portraits or street photography after asking for permission. In these instances, you will have more time to make sure to nail the focus even at wider apertures.