Digital Camera World » aperture

DoF defined: controlling depth of field in photography

jmeyer — Wed, 10 Oct 2012 11:12:51 +0000

When you focus on a subject part of the scene in front and behind it is also sharp. This sharp zone is known as the depth of field – or DoF – and understanding how to control the size of your depth of field is one of the most important aspects of photography to get your head around.

It’s useful to have lots of depth of field in landscape photography, for instance, because the aim is usually to have the entire scene sharp from the rocks in the foreground to the horizon in the distance.

In portrait photography, however, we often want to restrict DoF a little so that the person is in sharp focus, but the background is blurred. This makes the sitter stand out while the background is a little less distracting.

On some occasions it’s nice to have very limited depth of field so that only a small section of the image is sharp and a lot of it is blurred. This is a technique that is often used in fine art photography or to draw attention to the subject and inject a little atmosphere.

Let’s take a look at the factors that affect depth of field and how you can control DoF in-camera.

PAGE 1: What is depth of field?
PAGE 2: Controlling depth of field via your aperture
PAGE 3: Controlling DoF by focal length
PAGE 4: Subject distance and depth of field
PAGE 5: Using all three factors to control DoF

Photo of the day: 19 August

samanthacliffe — Sun, 19 Aug 2012 06:00:08 +0000

Morning Dew by Vincent Nursalim

This is a simple and well executed shot. The viewer’s eye is neatly drawn to the dew drop in the centre of the image. The wide aperture provides a shallow depth of field and creates a bokeh effect to the water drops toward the edge of the image.

View more photography from Vincent.

You might also like:

Aperture vs Depth of Field: photography cheat sheet
Depth of field: what you need to know for successful images
Or view more inspirational photography

Photo of the day: 15 August

samanthacliffe — Wed, 15 Aug 2012 14:59:52 +0000

Golden Lady by ‘yappingjak‘

The wide aperture beautifully eliminates all distractions and focuses attention entirely on the tiny ladybird. This is perfectly executed and a great demonstration of how to draw attention to such a small subject, which is something than many photographs struggle to do well.

You might also like:

Aperture vs Depth of Field photography cheat sheet
Depth of field: what you need to know for successful images
99 common photography problems (and how to solve them)
Or view more inspirational photography

Aperture vs Depth of Field: photography cheat sheet

jmeyer — Mon, 13 Aug 2012 11:35:27 +0000

What is aperture, you might be wondering if you’re new to photography? Your digital camera’s aperture is simply a hole in the lens – a variable diaphragm that can be made larger or smaller – to control how much light reaches the sensor. In this quick tutorial we will explain what you need to know to get started taking more control of your depth of field, photography skills and when you can put these into practice.

You control the aperture size using the dial on your DSLR (or it is set for you by the camera). The aperture size is measured on the f/stop scale.

The numbers on this scale can be hard to understand; f/8 is larger than f/16, as they are actually fractions, so f/8 is an eighth, and f/16, a sixteenth.

Your choice of apertures will vary depending on the lens you are using, but will generally range from a widest setting of around f/4 (as seen in the portrait above) to a narrowest of around f/22 (as seen in the image at the top of this page); some lenses will offer a wider or narrower range of values.

The aperture also jumps in a seemingly illogical steps – which ultimately you will just have to get used to. The key sequence to remember is the ‘full stop’ range – f/4, f/5.6, f/8, f/11, f/16 and f/22.

Each step along halves the amount of light reaching the sensor (and this can be compensated by doubling the shutter speed).

For more on this, see our photography cheat sheet on when to go small and when to go wide.

Click here to see our latest photography cheat sheet on aperture vs depth of field.

Annoying problems at common aperture settings (and how to solve them)

jmeyer — Fri, 10 Aug 2012 01:00:59 +0000

One of the most important steps in learning about photography is understanding how to use aperture, because controlling your lens’ aperture settings enables you to take control over depth of field and dictate the size of the sharp area around the focus point in an image.

If you want a lot of the image to be sharp, for example, you need to select a small aperture setting such as f/22 and if you want to restrict the depth of field to isolate a subject from the background, you need a nice wide aperture setting such as f/2.8 or f/2.0.

Whatever aperture setting you use, you need to select an appropriate shutter speed to ensure that the image is correctly exposed.

If you shoot in aperture priority mode (often signified by A or AV on the mode dial), you set the aperture setting that you want while the camera takes care of the shutter speed.

Most cameras allow you to adjust aperture in 1/3-stop or EV steps. In this article we’re going to take a look at some of the common problems with using wide, middle and small aperture settings and explain how to overcome them.

Problems at wide aperture settings
Problems at middle aperture settings
Problems at small aperture settings

Apertures: when to go small and when to go wide

jmeyer — Wed, 16 May 2012 10:36:12 +0000

One of the most common questions we hear from readers and new photographers is when to use wide apertures and when to use small apertures (see also some of the other 99 most common photography problems we get asked).

The source of the confusion around apertures often tends to be around the f-numbers. The smaller the f-stop (eg f/2.8) the wider your aperture will be, and thus let in more light.

The bigger the f-stop (eg f/22) the smaller your aperture will be. Once you get your head around that numbering system it becomes much clearer and you will soon be using apertures confidently to achieve different effects.

Below, the latest infographic in our photography cheat sheet series takes a closer look at why you would use small apertures and why you would use wide apertures. We show an example of each, and also illustrate how your apertures look at each f-stop to give you a better idea of how much light you are letting into your camera.

Feel free to drag and drop this cheat sheet on to your desktop and save it for reference.

How to find your lens’ sweet spot

jmeyer — Mon, 16 Apr 2012 15:38:23 +0000

What is a lens sweet spot? It’s something you’ve probably heard mentioned before, but all a lens’ sweet spot means is the aperture setting at which it is the sharpest (learn how to Master your aperture with our free f-stop chart).

It’s important to understand that your lens doesn’t retain the same level of sharpness throughout its aperture range, so by finding your lens’ sweet spot you will put yourself in a better position for getting sharper images.

The unofficial rule states that your lens’ sweet spot will usually sit somewhere in the mid-range apertures of f/8 to f/11. But how do you find that sweet spot? Here’s how to do it in three easy steps.

How to find your lens’ sweet spot

Step 1: Set your digital camera on a tripod and attach a sheet of newspaper to a flat wall (see 4 tips for sharper shots when using a tripod). The share price pages from a broadsheet work best, as you get small text across two pages.

Step 2: Make sure your lens is pointed straight at the paper. Focus on it, then take a series of pictures at each full aperture stop (f/4, f/5.6, f/8, f/11, f/16 and f/22, for example).

Step 3: Look at the shots on your PC screen, zooming in to 100%. You’ll see a difference in clarity and contrast between each setting.

Free f-stop chart: master your aperture

jmeyer — Sat, 17 Mar 2012 10:30:13 +0000

One thing we consistently hear from people is confusion about aperture and just what exactly those numbers mean. Understanding aperture can take some time for a beginning photographer, but hopefully we can speed this process up for you! Below is a handy f-stop chart put together by our friends at N-Photo magazine which you can drag and drop on to your desktop.

Print it out – print three out! – and stick it in your camera bag. The sooner you start understanding aperture and f-stops, the sooner you’ll start to get sharper, more creative pictures.

Like this? Here’s more free stuff

50 free photo frames

25 free triptych photo frames

10 free photo grids for Photoshop

Get to know your camera

crutter — Thu, 08 Dec 2011 11:17:08 +0000

This guide is written for anyone who wants to get more from their camera, be it an SLR, compact system camera or bridge camera. It works as a complete beginners’ guide, but is also a handy refresher course for people who’ve had their camera for a while.

I remember how intimidated I was by my first ‘proper’ camera, and how much I could have benefitted from a jargon-free guide like this. In the articles below, you’ll learn all about your key camera controls – what they are, and more importantly, how to use them to get great shots. Read on to discover how to control exposure for perfectly balanced shots, adjust aperture and shutter speed, use flash, and much more. We also explain how to choose and use a lens, and how to get more from your photo-editing software and printer. Enjoy this unique beginners’ guide, and please do share any shots it’s inspired you to take!

Part 1: Set up your camera

Part 2: Explore your SLR

Part 3: Get better exposures

Part 4: Understanding aperture

Part 5: Shutter speed explained

Part 6: Perfect your exposures

Part 7: Focus modes explained

Part 8: Choosing a lens

Part 9: Flash modes explained

Part 10: Image editing, printing & storing

Part 11: Essential accessories

Part 12: Looking after cameras

Set up your camera

crutter — Thu, 08 Dec 2011 11:16:27 +0000

Congratulations on getting a new camera! It’s only natural that you can’t wait to start using it, but it’s worth spending a few minutes configuring it correctly first. Not only will this save you time and effort in the long run, but it’s a good way of familiarising yourself with your camera’s layout, features and functions. With the help of our quick-start camera set-up guide, it will only take a few minutes…

Select high-quality pictures

When it comes to file format, shoot in raw rather than JPEG. The extra data that’s captured in the uncompressed raw format gives you more flexibility to adjust your shots post-shoot if necessary (see page 7 for more on the raw file format). Try to keep the ISO as low as possible, ideally between ISO100 and 400, because digital ‘noise’ can be a problem at high ISO settings. As for white balance, set it to auto for now – as you progress you’ll become more confident at knowing when to switch to a specific setting, such as Cloudy.

Choose the right exposure mode

SLRs offer a range of exposure modes, from fully automatic – like a point-and-shoot camera – to fully manual. In between these two extremes are the two popular ‘semi auto’ modes – aperture priority and shutter priority – which provide lots of creative control. In aperture priority mode, you set an aperture and the camera automatically works out what shutter speed you need for a correct exposure, while in shutter priority mode, you set the shutter speed and the camera works out the correct aperture. Simple!

Choose the right metering mode

Metering options depend on the camera, but the three most common are multi-zone (also known as evaluative or matrix), centre-weighted, and spot. Multi-zone mode takes a reading from the entire scene and then sets the exposure accordingly. It’s pretty accurate, and is suitable for most conditions. Centre-weighted mode takes a reading that concentrates on the central 60% of the frame, making it ideal for portraits, and spot mode takes a reading from a tiny area and is therefore potentially the most accurate.

Set the aperture and shutter speed

Aperture and shutter speed affect not just the amount of light you let into the lens, but also the way images look. The aperture is used to determine the depth of field, which is the amount of the scene that’s in focus. If you want a blurred background, you need a wide aperture, such as f/2.8; and if you want everything in focus from front to back, you need a narrow aperture, such as f/22. The shutter speed controls whether a moving subject is frozen or blurred; the slower the shutter speed, the more motion blur there will be.

Set the focus and drive modes

To ensure your shots are razor-sharp, SLRs offer a number of focus modes. The two main settings are single-shot, mainly for stationary subjects, and continuous or servo, for moving subjects. Most SLRs feature multiple focus points that can be selected manually. The drive modes enable you to select whether a single shot is captured each time you press the shutter release, whether a sequence of shots are taken in rapid succession, or whether the shutter is fired after a delay of two or ten seconds.

Take a test shot

Now you’ve set up your SLR, it’s time to ensure you’re using its LCD properly. By this we mean using the zoom buttons to zoom in on parts of the image on the rear screen, so you can check for sharpness or excessive noise. And you should also try to get into the habit of checking your image’s exposure by calling up the histogram, or tone chart. A histogram bunched up at the left can indicate under-exposure; a histogram at the right suggests over-exposure. If you’re unsure, adjust your settings and try taking another test shot.

Back to: Get to know your camera – introduction

Forward to: Explore your SLR