Digital Camera World » DLSR tips

Break the rules: become a pro at using backlight to add drama to any photo

jmeyer — Sun, 15 Jul 2012 05:00:17 +0000

All images by Mark Hamblin

Read any guide to successful photography and it will invariably advise you to shoot with the sun behind you to illuminate your subject from the front. This is sound advice, and of course this will often produce very good, evenly lit images. However, rules are sometimes there to be broken – what about shooting directly into the light to create dramatic backlit pictures?

The prospect can be a bit scary and there are certainly a few common pitfalls to watch out for, but once mastered, backlighting – or ‘contre-jour’, as it’s also known – can give your shots a little extra something and make all those front-lit shots look rather ordinary by comparison.

Backlighting doesn’t work in all situations, or with all subjects, so a cautionary approach is required -– as is an element of experimentation. Learning to recognise the kind of lighting situations and subjects that can be backlit effectively is perhaps the initial key to success.

In theory, any form of light can be used to backlight a subject, but the stronger the light source, the greater the backlighting effect will be (check out this cool backlight technique for still life photography).

The angle of the light is also very important. Midday sun, for example, can be used to backlight a subject, but the  light will be coming from a high angle, creating a great top-lit, as well as slightly backlit, effect (for more on this, see our guide See the light like a pro: everything you were afraid to ask about natural light).

When the sun is positioned nearer the horizon, early and late in the day, the subject will be solely backlit, with a much more pronounced and therefore dramatic effect. For the same reason, the winter months are considerably better than the summer ones to take shots like this, because the arc of the sun is lower in the sky, which produces a much more pleasing backlit result.

A host of subjects work well – portraits, birds, animals, plants and flowers, to name just a few. Backlighting is a very effective way to reveal the delicacy and texture of semi-transparent subjects.

Similarly, hairy animals, or those with a distinctive shape, work really well, because the details at the edge of the subject are highlighted. Backlit subjects will also create a shadow that extends towards the camera, which instantly adds essential interest.

But regardless of the subject or the form of backlighting, the picture will triumph or fail on one thing alone – good exposure. Master this and you’re almost guaranteed a successful shot. Importantly, you must expose for the subject and disregard the background.

For most subjects, it’s fine to shoot using a metering mode that takes an average meter reading from all areas of the frame, such as Evaluative or Matrix (check out our free metering mode cheat sheet on how your modes work and when to use them).

But back-lit images shot in this mode will often fail, because the light in the background significantly affects the reading and leads to an under-exposed (or even silhouetted) subject.

To counter this, you need to switch to either Spot or Partial metering, which allows you to take a very specific meter reading directly from the subject.

PAGE 1: What is backlighting?
PAGE 2: 3 ways to achieve backlight effects in-camera
PAGE 3: Backlighting portraits
PAGE 4: Crucial backlighting tips to remember

What is ISO? When to increase sensitivity, types of noise and more

jmeyer — Wed, 20 Jun 2012 03:00:15 +0000

If you’re new to photography you may have asked yourself, ‘What is ISO?’

Back in the days before digital, film came in a variety of different speeds. The ‘faster’ the film, the more sensitive it was to light – allowing you to use faster shutter speeds than with ‘slower’ film.

Using these higher-sensitivity film emulsions was useful for moving subjects – and particularly so in low light. This film speed was measured using a number of different scales – with two of the best known, the American ASA and German DIN scales, eventually being brought together to give us the standardized ISO system.

ISO 1000 - 1/15sec at f/5.6

Digital cameras, of course, do not use film – but the same ISO scale is now used to measure the camera’s sensitivity to light. Although the camera’s imaging chip cannot be changed to suit the subject (unlike film), its sensitivity can effectively be boosted by the camera’s circuitry.

This is done with the ISO control. Think of ISO as being like the volume control on your radio. If the signal is weak, you crank it up to compensate.

The signal from the sensor is simply amplified – and this helps you get the fast enough shutter speed you want in low light.

The crops inset are shown in actual pixels.

Digital advantage
The advantage of digital over film is that the ISO can be altered for each individual shot. This makes ISO a powerful tool for the photographer, helping you to get sharp shots in a variety of lighting conditions.

ISO is the name of the International Organization of Standardization: a body that creates thousands of agreed standards for a huge range of products, procedures and practices.

For the photographer, ISO is simply a set of numbers. The base sensitivity of all current Canon EOS SLRs is ISO 100.

But this can be increased by pressing the appropriate button, then rotating the main dial (on some older cameras ISO is changed through the Menu button).

The scale is such that doubling the ISO number doubles the sensitivity of the sensor. So increasing the ISO setting from 100 to 200 means that, to get the same overall exposure, you can use a shutter speed that is half as long (or twice as fast).

Each doubling of the ISO also increases the sensitivity by a full exposure ‘stop’ – with the typical full-stop ISO scale progressing 100, 200, 400, 800, 1600, and so on. The top ISO setting varies depending on the age and cost of your digital camera – from ISO 3200 to a staggering ISO 102,400 on some models.

Bizarrely, the top ISO settings on many models are ‘hidden’, and must be enabled using a custom option called ‘ISO Expansion’. The reason for this is that each time you increase the ISO setting, you also get a small decrease in image quality.

Boosting the picture signal also amplifies impurities in the signal known as ‘noise’. This noise shows up as grain and colour mottling in the image – and this gets progressively more noticeable the higher the ISO is set.

How ISO works: cheat sheet

It’s one thing to read about how ISO works. It’s another thing to see it. In the infographic below we’ve illustrated what happens in terms of sensor output as you adjust your ISO for low light. Click on the infographic to see the larger version, or drag and drop this photography cheat sheet directly on to your desktop to save if you’d like to keep it as a handy reference.

When to increase ISO
Some photographers try to resist increasing the ISO at all costs in search of getting the best, grain-free images. However, pumping up the ISO often actually increases image quality overall, as this simple change lets you use a faster shutter speed – thereby eliminating camera shake.

A grainy picture is always better than a blurry one! A higher ISO can also enable you use a narrower aperture – increasing depth of field, and thus increasing the resolution of a lens – to give you sharper-looking pictures.

Although higher ISO settings are invaluable in low light, they are not essential for all low-light situations, in fact, if you can keep the camera steady, they are often best avoided (find out how to reduce noise at high ISO settings).

If you are using a solid tripod, the slowest ISO setting (ISO 100) is usually the best option – as you can then use a longer shutter speed to make up for the lack of light.

Similarly, if you are using flash, high-ISO settings are not needed (although increasing the ISO will increase the effective range of your flash).

Types of noise
There are two different types of noise found in digital images. Luminance noise shows up as a speckled pattern, like specks of black sand, and is similar to the grain that was found when using high-ISO black-and-white films.

Chromatic noise is coloured and looks like the rainbow-like sheen when looking at a patch of oil (and is similar in appearance to the blotchy dye patterns that you saw when enlarging high-ISO colour films).

The crops inset are shown in actual pixels.

It’s important to look at these two types of noise separately – as each can be reduced using different tools during the editing stage. These are often provided as separate noise-reduction sliders by a RAW converter (such as in Adobe Photoshop’s Camera Raw utility).

Specialist software (such as Noise Ninja and Dfine) is particularly useful for reducing noise without sacrificing detail.

How to set up your DSLR for video recording

jmeyer — Sun, 25 Mar 2012 07:00:23 +0000

Are you a struggling HDSLR filmmaker? The first step towards shooting a compelling DSLR video is to set up your camera properly. To help you find your way through the puzzling onboard movie-making options, we’ve used a Canon DLSR to explain some of the typical settings you’ll be using when shooting HD video on your DSLR…

DSLR Video: how to set up your camera to record HD movies

Step 1: Choose the definition 
Decide on the resolution you want to shoot your movies at. This will partly depend on what you need your video for, but it will also be determined by how long you want the maximum clip length to be.

Step 2: Set the frame rate 
Some cameras provide a choice of frame rates. The standard for Europe is 25fps and 30fps is the default for the USA. Use 24fps for a cinematic look – or choose 50 or 60fps for a cool slow-motion effect.

Step 3: Sound options 
Your DSLR will also record sound, but this needs to be planned carefully to be of any use. If you’re going to add a commentary and music, you may simply want to turn the sound recording off.

Step 4: Mic mechanics 
To improve your sound, use a plug-in microphone. A hotshoe mic is a simple option, but a tie-clip mic on a long lead is a good low-cost solution for recording someone speaking.

Step 5: Switch to manual focus 
Your camera may be able to autofocus while recording, but you can’t rely on it to stay on target for the full take. Any errors could ruin the shot, so consider switching to manual.

Step 6: Using AF
If you must use autofocus, pick the option with care. You can use live and face detection options while recording, but Canon’s Quick mode should only be used beforehand.

DSLR Video: a beginner’s guide to shooting HD