1/100 sec at f/18; ISO200

Scalpel-sharp pictures aren’t just the result of holding the camera steady when you take a picture (although that plays a significant part). Your choice of shutter speed and aperture, the quality of the lens and how accurately it’s focused, and the amount of sharpening that’s applied – either in-camera or with software – all contribute to the sharpness of your images. Supporting the camera while you take a shot is key though. The rule of thumb for handheld shooting is to make sure that the shutter speed is equivalent to or faster than the focal length of the lens, expressed as 1/focal length. So if you’re shooting with a 100mm lens you should be able to get sharp shots at 1/100 sec or faster: switch to a 20mm wide-angle lens and you should get away with 1/20 sec. This rule only holds for full-frame D-SLR’s such as the EOS 5D. Because the sensors in the majority of Canon D-SLRs are smaller than full-frame, the angle of view (what the lens ‘sees’) is narrower – and consequently, the effects of camera shake are magnified. As a result, the exposure needs to be shorter, so by multiplying the focal length by x1.6 (the sensor’s ‘crop factor’), you get the full-frame equivalent focal length that can be used to work out the safe shutter speed. For instance, a 50mm lens effectively becomes an 80mm focal length on a 600D (50mm x 1.6), meaning that you shouldn’t let the minimum shutter speed drop below 1/80 sec for handheld shots.

No great shakes

While some photographers can take shake-free pictures at speeds slower than recommended, others struggle with exposures that are twice as fast. Canon’s Image Stabilization (IS) lenses can help here. They improve the chances of getting sharp pictures by adjusting an element within the lens to counteract the effects of movement. But while IS often makes the difference between a sharp picture and a soft one, it can’t work miracles. The shutter speed still needs to be fast enough to freeze the movement of an active subject. When light levels drop and shutter speeds get slower, you’ll need a tripod to keep the camera solid. And even when there’s plenty of light, a tripod enables you to use low ISO settings for smooth, noise-free shots, as well as giving you freedom over the choice of aperture.

The aperture setting itself has a role to play in sharpness, as the choice of aperture affects the depth of field in an image; the more of this there is, the more of an image from front to back will appear sharp. Narrow apertures (with high f-numbers such as f/16 and f/22), create greater depth of field, while wide apertures (with low values such as f/2.8 and f/4) offer a shallower depth of field. Dialling in a lens’s narrowest aperture setting doesn’t lead to the sharpest results though. Not only will shutter speeds be at their slowest, but due to an optical effect called diffraction, images can actually appear softer. The ‘sweet spot’ of sharpness for a lens is usually in the aperture mid-range, around f/8-f/11.

Naturally, pin-sharp pictures can only be captured if a lens is focused with precision. It’s faster to use the camera’s auto focus system to get things crisp than to rely on manual focusing, though you’ll need to select the auto focus mode that’s appropriate to the subject or scene you’re photographing. For static subjects, choose One-Shot AF – this will only let you take a shot when a part of the image is detected to be in focus. Shooting a moving subject? Then switch to AI Servo AF, which continuously adjusts the focus as the subject moves. You also need to make sure the auto focus system picks out the part of the scene that you want to be in focus. To do this, you’ll need to highlight the area using one of the AF points in the viewfinder. It’s better to do this yourself rather than letting the camera pick the point(s) of focus, as it will often latch on to the closest thing to the camera; if you’re taking a portrait, this may mean all the detail of your subject’s nose is rendered sharp, instead of their eyes!

What it takes to get a sharp picture…

1. Aperture

Narrow apertures enable you to increase the depth of field in an image – press the Depth of Field preview button to check what’s sharp.

2. Focus

With landscapes, focus around a third of the way into the scene in order to maximise front-to-back sharpness. Use Live View to magnify an area, and then fine-tune with manual focus.

3. Support

A sturdy tripod and head will provide a stable base for the camera.

4. ISO

Low ISOs give the most detail-rich pictures, but you may need to up the ISO in order to use smaller apertures and/or faster shutter speeds.

5. Contrast

High-contrast subjects and scenes look sharper than low-contrast ones

Step by step – How to check for sharpness

Use Live View, or zoom in during image playback, to check that the area you want is sharp.

1. Activate Live View

Live View is handy when the camera’s on a tripod, as it makes it easier to focus. Press the START/STOP button or the button with the camera icon (depending on the model).

2. Highlight

Move the white rectangle over the area you want to focus on using the control dials or thumbstick. This indicates the area that will be magnified in the next step.

3. Magnify

The majority of Canon D-SLRs have two buttons at the top of the thumb rest with magnifying glass symbols. Tap ‘+’ to zoom into the image during Live View, or image playback.

4. Manual focus

Pressing ‘+’ once magnifies the image x5, and pressing it again takes it up to x10. With your lens set to MF (Manual Focus) gently turning the focus ring to fine-tune the focus.

Steady as she goes

Although you might be capable of getting acceptably sharp images when shooting with your camera handheld at fairly fast shutter speeds, it’s only by zooming in to view them at 100% on your camera’s LCD screen or your computer (when it’s too late to re-shoot of course) that you can really see if they’re bitingly sharp.

This image was shot handheld at 1/200 sec at f/8 with a focal length of 235mm.

Tripod Technique

Even shots that are taken with the aid of a tripod can appear soft if the tripod’s not set up and adjusted correctly. For a start, you should avoid raising the centre column where possible – this essentially turns the tripod into a less substantial monopod. Ideally, you should raise the camera to your eye level by extending the legs alone. Once the camera is locked on the tripod and you’re ready to take the shot, you shouldn’t touch it. Instead, fire the shutter using the camera’s self-timer or, if timing is critical, using a remote release. You should activate the mirror lock-up for exposures of 1/15 sec or slower too, as this will stop the vibrations caused by the mirror slapping up and down inside the camera from being transferred to the picture.

Mirror lock-up - Usually a custom function, although it’s found in the main shooting menu on the 5D Mk III

Self-timer - Activate this by pressing the Drive button and turning the control dial

Accurate focus point

Getting the right parts of a picture in focus is essential to creating an overall impression of sharpness. Focus is critical when you’re photographing close-ups where depth of field (the area that appears sharp) can be measured in millimetres, or when you’re using wide-open apertures, such as f/2.8 or f/4. Manually selecting a focus point to match the most important features in the photograph is key to good results. Choosing an AF point also enables you to keep off-centre subjects sharp, without having to recompose.

Lens matters

Generally, prime lenses (ones with a fixed focal length) deliver sharper images than zooms, with macro lenses particularly well-tuned to bring out the finest details. To get the best from any lens though, try to select apertures from the middle of the range and avoid placing the subject too close to the edge of the frame, as a lens is sharper towards its centre than at the edges.

No tripod? Try bracing your lens against a solid object for sharper images than you’d get by handholding.

One of the big benefits of your Canon EOS D-SLR is being able to take full control of your exposures. This means, unlike many auto compact cameras, with your D-SLR you can set the exposure to suit the type of photo you’re trying to take. There are two main factors to control when setting your exposure: aperture and shutter speed. The aperture is the opening in your lens, ranging from wide (e.g. f/3.5) to narrow (e.g. f/22), while the shutter is inside your D-SLR and stays open for the duration of your shutter speed. Aperture and shutter speed combine for a good exposure. The Av (Aperture Value, aka Aperture Priority) mode is a great semi-auto shooting mode available on all EOS cameras. It’s ideal to get to grips with if you’re trying to break out of the Full Auto (green box) shooting mode and a little intimated by using Manual mode. In Av mode, you can take full control of your aperture settings from wide to narrow, and your EOS camera automatically sets the shutter speed for a standard exposure.

Depth of field

Your aperture setting also affects depth of field (DoF): how much of your scene appears sharp before and after the point you’re focusing on. Wide apertures (e.g. f/2.8 to f/5.6) capture a shallow depth of field, so pretty much everything before and after your focal point will be knocked out of focus. Mid-range apertures (e.g. f/9-f/11) will capture the majority of your subject or scene in focus. Narrow apertures (e.g. f/16 to f/25) capture a large depth of field, so pretty much everything before and after your focal point will be acceptably in focus. For these reasons, it’s good to use wide apertures when photographing subjects you want to stand out from their surrounding, such as people and wildlife, because a wide aperture will blur backgrounds. And that’s why it’s good practice to use narrow apertures when photographing landscapes – you want to ensure your scenes are in focus from foreground through to the horizon.

Wide aperture – f/5.6                                   Middle aperture – f/9                                 Narrow aperture – f/22

Focal lengths

When setting your apertures, you also need to be aware how the focal length on your lenses will affect depth of field. Basically, the wider-angle your focal length (e.g. 18mm on your kit lens) the more depth of field you’ll obtain, even at wider or middling apertures. This is why wide-angle lenses are great for shooting landscapes and cityscapes when you want the whole scene in focus, and why you can shoot with a wide lens at around f/8-f/11 for cityscapes and architecture while still ensuring the scene is acceptably sharp throughout. Longer and shallower Conversely, the longer and more telephoto your focal length (e.g. above 70mm), the less depth of field you’ll obtain – which is why telephoto lenses are brilliant for portraits and nature photos. They help to further blur foregrounds and backgrounds so your subjects stand out in your photos. Your angle of view also changes depending on your focal length. Wide-angle lenses will capture a big angle of view; whereas there’s a dramatically reduced angle of view the longer your telephoto focal length. So be careful when shooting full-face portraits: wide lens = distorted faces, but telephoto lenses = slimmer – and much more flattering!

15mm                                         55mm                                         100mm                                       300mm

Exposure compensation in Av mode

If your exposures aren’t to your liking, use exposure compensation to brighten or darken the results.

1. Setting exposure compensation

Set the mode dial to Av and use the rear thumbwheel (60D-type D-SLRs) or hold down the Av+/- button and use the top dial (600D-type cameras).

2. Shutter speed adjusted

When shooting in Av mode (which locks your aperture setting), dialling in exposure compensation will adjust the shutter speed.

3. Brighter shots

Nudge the exposure level indicator to the right (dial in +1-stop exposure compensation) to brighten your images – the slower shutter speed will let more light in for a brighter photo

4. Darker shots

Pop the exposure level indicator left (dial in -1-stop exposure compensation) to darken images – a faster shutter speed will let less light on to your sensor, creating a darker image.

Read more…

When’s it best to use Manual mode on your Canon D-SLR

When’s it best to use Tv mode on your Canon D-SLR

Take control of depth of field

Master Aperture Priority mode

Getting the focal point spot on can be tricky, especially if you’re shooting with a wide aperture such as f/4. But don’t panic, because there is another way.

By capturing the image above with a tight aperture of f/22 we were able to get more of the watch in sharp focus, and then control the depth and the intensity of the bokeh in Photoshop.

Here, we’ll show you how to mimic a realistic bokeh using Photoshop CS5’s sophisticated Lens Blur filter, which can add the natural-looking blur effects produced by various lenses.

Our original shot

By applying the blur to a separate layer you can control its intensity and then use layer masks to make the blur blend in gradually, just as it would when shooting with a wide aperture f-stop, such as f/2.8.

By applying the Gradient tool to the layer mask you can take precise control over where the sharpest areas begin to blend with the bokeh, so that you can recreate different depth of field effects without fiddling with the camera’s aperture settings.

Step by step how to use the Photoshop Lens Blur filter

01 Add a layer mask
Open your start in Photoshop. Go to Window>Layers, double-click on the locked Background layer thumbnail, then in the New Layer window hit OK. Click the Add Layer Mask icon at the bottom of the Layers palette and a white mask will attach itself to the layer.

02 Set up the Gradient tool
Grab the Gradient tool from the Tools palette. Press D to turn the foreground and background colours to the default white and black. Click on the Gradient Editor and select Foreground to Background. Hit OK. Click on the Linear gradient in the options bar.

03 Draw a gradient on the mask
Drag upwards to draw a white-black gradient. White makes the pixels solid, grey semi-transparent and black transparent. Grab the Brush tool and set Opacity to 24% and Foreground Colour to Black. Spray on the mask to make the lower corners semi-transparent.

04 Add lens blur
Click back on the image layer and go to Filter>Blur>Lens Blur. Set the sliders to 0 to see what each one does. Tick Faster, then go to Depth Map and set the drop-down menu to Layer Mask. Tick Invert and set Radius to 96. Masked areas will become blurred.

05 Add specular highlights
To add realistic specular highlights to the bokeh, drag Brightness up to 27. To limit the blown-out highlights to just the brightest reflections, increase the Threshold to 235. Experiment by changing the Iris shape to Square (4). This creates a realistic four-sided specular highlight at the top of the watch.

06 Go with the grain
To make the clean bokeh areas look like they were blurred in-camera, raise Noise Amount to 2 pixels. Choose a Gaussian distribution, then click OK to create your natural bokeh effect. You no longer need the layer mask because the Lens Blur filter has finished using it, so choose Layer>Layer Mask>Delete and you’re done.

READ MORE

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Image copyright David Clapp

Controlling depth of field is the key to successful photography. Managing what is in focus (and out of focus) is strongly linked to the enjoyment of the image and this varies greatly with relation to subject matter. Landscape photography, for example, uses a large depth of field, keeping the entire image in sharp focus from corner to corner. This invites the eye to explore fine detail and truly experience distances, from distant cloud shapes to the wet sand at your feet.

Macro photography, on the other hand, places these sharp areas alongside large out-of-focus areas (find out How to set your autofocus for macro photography). A fine stamen set against a riot of soft blurred shapes renders a flower delicate and the experience becomes more intimate.

The next time you look at some compelling advertising, identify what the advert is trying to sell and the photographic technique used to reflect this.
Whether it’s jewellery or a package holiday, the depth of field will keep your eye exactly where it should be – on the product. So how can you improve your use of depth of field?

Understanding your lenses intimately is the best answer (check out The Canon lens companion for more on how to use your lenses).

Depth of field increases either side of the focal plane (or focal point) as the aperture is increased, bringing areas either side of this sharpness into focus. A wide aperture (such as f/2.8) will contain very little of the image in focus whereas a large aperture (such as f/16) will render much more of the image sharp (download a free f-stop chart for understanding aperture).

This is again subject- and lens-dependant. There is no reason to shoot a distant landscape with a telephoto lens at f/16 because it doesn’t contain anything close to the photographer.

A wider aperture will suffice. Telephoto lenses exhibit a far reduced depth of field at f/16 than a wide-angle lens, so understanding just how much your lens can render is vital to an image’s success.

Focus your lenses

Learning to focus your lenses hyperfocally is the answer to many landscape headaches (see a quick guide to What is hyperfocal distance? Or you can drag and drop download our free hyperfocal distance calculator chart on this page).

Imagine a mountain scene containing a house and some garden flowers around a metre away. It is possible to shoot all this in focus if the focusing is positioned correctly to use the areas in front of and behind the focal point.

With the lens focused on the mountain (at infinity) the flowers in the foreground can’t seem to get focus, even at f/22. This is because the area behind the focal plane is not being used. By moving the focal point back towards the house, the lens now uses the area both in front and behind, which means the flowers snap into focus without losing sharpness throughout the image.

Essential camera tips for controlling depth of field

Take manual control
When setting depth of field, set the camera to Av or M (Aperture Priority or Manual) to make sure you have complete control over your composition and the areas that appear in focus. Keep your lens switched to manual focus (MF), too.

Use Depth of Field Preview
Your camera’s Depth of Field Preview function is vital for assessing depth of field, before you press the shutter. Remember, until this button is depressed, the lens will only show the image at the widest aperture.

Switch to Live View
Live View (available on most modern D-SLRs) is your best friend. Press the Depth of Field Preview button while in Live View mode and you will be able to see exactly what’s in focus. This helps you position the focal point to maximise the in-focus area.

Depth of field and macro photography

Choosing the right aperture to shoot at for flower portraits can be tricky. Here’s how to get it right (click to enlarge the image below)

Flower portraits can respond well to varying depths of field, but identifying the right aperture can be tricky. Shooting this military orchid at a narrow depth of field creates a greater sense of dimension and also blurs the background out to a smooth green.

The f/16 shot, on the other hand, looks much more like a ‘record shot’, because the flower is entirely sharp. Basically, the aperture you choose depends on the effect you want to achieve. The joy of digital is that you can experiment on location until you get the result you want.

Final tips for controlling depth of field

Use a tripod
Image accuracy will make or break the shot, so ensure you have a steady tripod to mount your camera on. Vibration can also cause problems with softness, so ensure that all the locks and knobs are tightened up before shooting (see our 4 tips for sharper shots when using a tripod).

Speed things up
Wide apertures can let you break free of the tripod and shoot handheld instead, as a narrow depth of field (f/2.8, for instance) means faster shutter speeds. Vary the ISO to give even greater control and respect the 1/focal length rule (shooting with a 50mm lens at no slower than 1/50 sec).

Check your focus
Disable autofocus or engage 
it respectively, depending on your subject matter and picture style. Remember to check your focusing regularly when shooting landscapes using manual focus. Mistaking the focus ring for the zoom can ruin all your shots.

Bracket your focusing
Try moving the focusing either side of the assumed focal plane when you’re shooting 
at greater depth of field. Take 
a few initial shots, then shoot a few extra exposures at different focal points as a safeguard against focus error.

READ MORE

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Manua Focus: what you need to know to get sharp images
Still life photography: depth of field mastered in 8 steps

1. Clean up your backgrounds

Shooting at wide apertures of around f/1.8 to f/2.5 will blur distracting backgrounds, such as foliage or furniture, but the distractions are still there.

Instead, try to move around and recompose your shots or reposition your subject so the background behind them is cleaner. Shooting against a curtain or sheet can help here.

2. Ensure maximum depth of field

We know that higher f numbers indicate a narrower aperture, and a deeper depth of field. To set this automatically, choose the A-DEP mode on your SLR‘s mode dial. It automatically sets aperture and focus to ensure there‘s enough depth of field across the image. Handy for shooting landscapes!

3. Stay flexible

Even when shooting huge landscapes, you don‘t always want everything in sharp focus. Arguably the first shot in this bridge sequence is the strongest.

It was captured at f/1.8 for the shallowest depth of field and as a result, everything directly behindthen telescope, including the bridge, is nicely blurred.

You don‘t always need to have everything sharp - a suggestion of the background is often enough. This technique also works if you‘re taking portraits in busy places. The key here is to experiment and adjust depth of field to suit the scene, and mood.

4. Get to know focus modes

There‘s nothing worse than taking an action shot which you‘re sure is in focus, only to see that it‘s soft when viewed on your PC. To capture moving targets, use the AI Servo autofocus mode, which is designed to track objects and continually refocus when the focusing distance keeps changing.

Note that the AF beep won‘t sound even when focus is achieved. Used in conjunction with your SLR‘s high-speed burst mode (3fps on the 400D and 6.5fps on the 40D) you should find your success rate noticeably increases.

5. Eye-to-eye contact

In traditional portraits, the eyes are key. Shoot at a wide aperture of around f/2 and focus on one eye by getting your subject to turn very slightly to one side. Move your AF point if necessary for your close-up composition. This quick and easy trick really works.

6. Move your AF points

Choosing from one of several AF (autofocus) points has a big impact on your photos. In this group portrait photo, shot at f/10 aperture, the focus point was originally left in the middle.

As a result, the central girl is sharp and the girls either side are left slightly out-of-focus. This is a nice effect, but your eye doesn‘t really know where to look.

A more effective technique is to switch the AF point to the right (at 3 o‘clock) to make the girl on the right sharp, leading your eye into the shot.

7. Get an IS lens

IS (image stabilisation) lenses combat camera shake, effectively allowing you to use slower shutter speeds. You‘d normally end up with blurred shots when shooting handheld with a shutter speed of 1/50 sec, but with an IS lens this shot of Tintern Abbey remains sharp.

Without IS at 1/50 sec you‘d really see the difference. Many budget Canon lenses now come with IS as standard, so if a lot of your shots are spoiled by camera shake, it‘s definitely time to get one. Other makers offer versions of IS too.

8. Make the most of macro

Spring is great for macro photography, but striking macro shots require more than simply getting close. Focusing on one part of an object and thinking about creative composition will make a world of difference.

When shooting, don‘t panic if objects aren‘t kept entirely in the frame - as this example shows, it can actually enhance the subject matter. Cropping photos into a square can benefit this style of image, too.

9. Pre-focus perfection

Pre-focusing is great for motor sports photography because it enables you to focus on a spot ready for your subject to pass without relying on your camera’s AF mode to try and keep up with the action.

Switch to MF (manual focus) on your lens, focus on a spot on the road or track an area you know your subject will drive over, then fire the shutter when it does.