How to shoot macro photography this autumn

Your choice of aperture affects the 'depth of field' – or how much of your macro subject appears sharp. Low f-numbers such as f/2.8 and f/4 produce a shallow depth of field (only a small area in sharp focus), while high f-numbers such as f/11 and f/16 give you a larger depth of field (more of the subject in focus).

In close-up photography, even a large depth of field can measure just a few millimetres, so there's no room for error when it comes to focusing. The background is likely to be out of focus either way, but using a smaller aperture (higher f-number) will allow you to get more of your subject sharp while a bigger aperture (low f-number) will enable you to focus on a smaller part of the subject and throw the rest out of focus.

5. Shutter speed

When you change the aperture, either the shutter speed or ISO needs to change to maintain a consistent exposure. Changing the ISO can affect image quality, however, so it's a good idea to set your aperture and shutter speed to match your creative intent before changing the ISO.

Here's how it works: as the f-number increases, the aperture in the lens decreases in size. Less light enters the camera as a result, so the shutter speed has to become slower to ensure the image isn't too dark. If you choose a lower f-number, the aperture in the lens becomes larger, so the shutter speed has to become faster to prevent the image from being too bright.

It might seem odd that a low f-number such as f/4 gives you a large aperture and a high f-number such as f/16 gives you a small aperture, but it helps if you think of it in terms of fractions: 1/4 is larger than 1/16.

The shot above was taken at an aperture of f/2.8, which is the lowest aperture setting on the Canon EF-S 35mm f/2.8 Macro IS STM lens. As you can see, the shallow depth of field at this aperture creates a smaller area of focus and beautiful background blur.

6. ISO

Adjusting the ISO sensitivity gives you the freedom to combine smaller apertures and faster shutter speeds.

For the best quality images, try to use low ISO settings, such as ISO 100, ISO 200 and ISO 400. At these sensitivities, the shutter speed may become too slow to get sharp results when you set a small aperture or you shoot in low light.

Increasing the ISO will enable you to use a faster shutter speed, but higher ISO sensitivities can lead to increased image noise – the digital equivalent of film grain. To reduce this, you can increase the strength of the camera's High ISO Speed Noise Reduction. You'll find this option in the camera's red shooting menu.

7. Getting creative

One of the advantages of macro photography is that you can create stunning images right on your doorstep. Everyday objects can become fascinating subjects as you show them in a new light, and you're free to experiment with camera settings.

One of the simplest ways to do this is to experiment with aperture. In the example above, the aperture was set to f/2.8. This image has a soft, blurred background but the pole of bamboo in the foreground is perfectly in focus.

This next shot (above) was taken at f/5. More of the background detail is visible when compared to the image taken at f/2.8.

Finally, the image above was taken at the smaller aperture of f/8. The exposure is similar to the other shots, but the background now has much more detail. This shows how small adjustments can make a big difference in the world of macro photography.

Autumn is a great time to practise macro photography. As greens change to browns and nature prepares itself for winter, you'll find beauty in the detail. Step outside your front door and take a closer look.


Written by Ian Wade and Marcus Hawkins