Digital Camera World » depth of field

Focus Stacking: how to extend depth of field when shooting close up

jmeyer — Sat, 18 May 2013 00:00:59 +0000

Shooting anything up close requires incredible patience and extreme precision. If your close-up photography isn’t sharp then you’re not only wasting pictures, but you’ve wasted hours of your time. In this in-depth tutorial we’ll show you how to use one of the most amazing Photoshop effects macro and close-up photographers can use: focus stacking.

Below we’ll show you step-by-step how to extend depth of field when shooting close-up by shifting your point of focus in multiple images, which you’ll later stitch together so you can produce images that are sharp throughout the frame.

One of the best things about close-up photography is the wonderful softness that results from working with such a shallow depth of field.

Even at the smallest apertures the plane of focus will stretch to a couple of centimetres at most, and anything outside this range will fall off into beautiful bokeh.

At times, however, this can be a problem –especially if you’d like a completely sharp subject. Stopping down the aperture will increase depth of field, but sometimes this simply isn’t enough to achieve sharpness across the subject from front to back.

The solution: fix the camera to a tripod and shoot several frames, each with a small shift in focus, then use Photoshop to combine the sharp areas to create a single pin-sharp image.

We’ll begin with a series of shots of a flower, captured with tiny incremental shifts in focus. We’ll make global adjustments to all the images at once in Camera Raw, then combine the sharp parts using the Auto-Blend command in Photoshop CS.

Macro subjects usually look best against clean uncluttered backgrounds, but this isn’t always easy to achieve when searching for the best angle.

We’ll neaten up our finished flower by creating a new colour co-ordinated background, then use the Clone tool to remove a few messy areas. Finally, we’ll utilise the High Pass filter for a great sharpening technique that works wonders on edges.

How to create a focus stacking effect: steps 1-2

01 Open in Camera Raw
Copy your start files into a folder on your hard drive, then open Adobe Bridge and go to the folder. Highlight the first image, then hold Shift and click the last one to select them all. Right-click over them and choose Open in Adobe Camera Raw to open the whole batch.

02 Remove the sensor mark
Click Select All at the top left. Now any changes will affect all the images. First let’s deal with the sensor mark on the left. Grab the Spot Removal tool from the Tools palette, set Type to Heal and Opacity to 100%, then drag a small circle over the mark to remove it.

Shallow depth of field: how to fake it using Photoshop filters and masks

jmeyer — Fri, 12 Apr 2013 23:01:27 +0000

In our latest photo editing tutorial we show you how to use a series of simple Photoshop effects to blur your background and create a shallow depth of field effect.

A shallow depth of field is a great way to focus attention on part of a scene by transforming the background into wonderful bokeh, which is why it’s a classic technique for portrait photography.

Normally you’d achieve shallow depth of field with a wide aperture of around f/2.8 or f/4. But aperture isn’t the only factor in shallow depth of field.

Focal length and the subject’s distance from the camera also play a part in giving your images a shallow depth of field.

The longer the lens and the closer the subject, the more of a shallow depth of field effect you will achieve.

Our before image

Conversely, shorter focal lengths and distant focus points result in deeper planes of focus.

Captured at f/4 with an 18mm wide-angle lens, the background in this scene is fairly sharp. We can employ Photoshop’s Gaussian blur filter to fake a shallow depth of field, focusing attention on the figure and blurring distracting details.

By applying different strengths of blur to duplicate layers then restricting the effect with Layer Masks, we can create a fall-off of sharpness either side of our digital focus point.

How to fake shallow depth of field

01 Select the figure
Open your start image. Hit Cmd/Ctrl+J four times to make duplicate layers. With the Quick Selection tool, paint over the figure. Use ] and [ to resize the brush. Hold Alt and paint to subtract areas from the selection. Go to Select>Refine Edge. Set Smooth 10, Feather 0.5 and hit OK.

02 Add to the selection
Go to Window> Layers to access the Layers panel. Rename the top layer ‘Sharp’. Grab the Selection Brush tool, set Mode: Mask and pick a soft circular tip. Paint over areas that would be the same distance from the camera as the figure to add them to the selection.

03 Create layer masks
Click the Add Layer Mask icon on the Layers panel to turn the selection into a mask. Highlight the layer below. Go to Filter>Blur> Gaussian Blur. Set Radius 1.5px. Hit OK. Name the layer ‘blur 1.5px’, then hold Alt and click the Add Layer Mask icon to add a full black mask.

04 Reveal the blur
Grab the Brush tool and set colour to white. With the layer mask thumbnail on ‘blur 1.5px’ highlighted, paint over the foreground and tree. Highlight the layer below, rename it ‘blur 3px’, apply the Gaussian Blur filter at that value, then Alt-click the Add Layer Mask icon again.

05 Apply stronger blur
Paint with white to reveal the stronger blur on the ‘blur 3px’ layer in the grass and scene behind the tree. Next highlight the layer below. Rename it ‘blur 6px’ then apply the Gaussian Blur filter at that strength to make the trees in the background appear more out of focus.

06 Boost the tones
Finally, use Adjustment Layers to boost the tones. Highlight the top layer, click the Create Adjustment Layer icon on the Layers panel and choose Brightness/Contrast. Set Brightness 6, Contrast 12. Next add a Hue/Saturation Adjustment Layer and set Saturation +7.

PHOTOSHOP CS BLUR GALLERY
While the blur filters available in Photoshop Elements can give realistic results, Photoshop CS6 offers more options. In particular, the new Blur Gallery has three filters that are designed to mimic shallow focus and tilt-shift effects, with greater control over the look of the digital bokeh. The new filters make it much easier to create the fall-off of sharpness achieved here with different strengths of blur.

Control depth of field to isolate subjects

jmeyer — Mon, 25 Mar 2013 11:00:31 +0000

Using depth of field creatively can make your focal point really stand out. In this quick tutorial we show you how to control depth of field to isolate subjects.

In the fight against distracting backgrounds, your aperture wheel is your biggest ally. Using a shallow depth of field to render your background out of focus will make your focal point stand out (so you’ll need to take care when focusing) as well as enhancing your image with pleasing out-of-focus areas or ‘bokeh’.

How to control depth of field

f/22

f/22
Shooting at an aperture of f/22 gives you an image that looks sharp throughout and, as a result, the subject can get lost. Small apertures (high f/stops) make busy scenes such as this one look like snapshots.

f/8

f/8
Taking the f-stop down to f/8 has made the image look less flat and one-dimensional, as the subject has been isolated a little. But the semi-blurred background is still distracting.

f/2.8

f/2.8
Opening the aperture to f/2.8 has given this image a lovely out-of-focus background, which in turn isolates the focal point leaves. It now looks creative and has a two-dimensional appearance.

Control depth of field carefully

Close-up studies, such as this lichen, lend themselves to shallow depths of field to isolate the subject. But even small apertures, such as f/22, can provide limited depth when working at such close distances.

The effects of aperture choice are magnified by longer lenses, with blurred areas becoming more prominent.

Depth of Field Preview: the button behind every sharp image you take

jmeyer — Sun, 10 Mar 2013 14:00:16 +0000

In this tutorial we show you step-by-step how to use your Depth of Field Preview button to check your test shots and ensure everything is as sharp as you want.

How to use your Depth of Field Preview button

01 Don’t trust the viewfinder
The viewfinder on a digital SLR is designed to be as bright as possible, and should give you an idea of what the shot would look like if you used the widest lens aperture available.

02 Use the Preview button
Most digital SLRs come with a Depth of Field Preview button. When pressed, this helpful button closes the lens diaphragm to the aperture currently set, so you can check the amount of depth of field.

03 Instant darkness
The problem with the Depth of Field Preview, however, is that it makes the viewfinder image go much darker – making it harder to see the effect that this feature is actually trying to show!

04 Zoom in
A better solution than using the Depth of Field Preview button is to take a test picture, and then review it on the LCD screen. Use the zoom function key (signified by a magnifying glass and a plus sign).

05 Look at the detail
The zoomed-in preview of your test shot on the LCD will typically give you 10x magnification, enabling you to check exactly which parts of the picture are sharp – or how much they are blurred.

06 Check in every corner
Use the cursor keys to move around the magnified image, so that you can see the full extent of the depth of field, and whether you need to adjust the aperture to get a better result.

Deep Depth of Field vs Shallow: 10 common questions and answers

jmeyer — Sat, 09 Mar 2013 02:00:19 +0000

Ever wondered why some backgrounds are pin-sharp and others are out of focus? This is what’s called deep depth of field and shallow depth of field. Find out how to take full control of this in-camera photography effect and answer any of the common photography questions you may have.

Click on the infographic to see the larger version

Common questions about shallow and deep depth of field (1-5)

What’s depth of field all about?
Depth of field is a measure of how much of a picture is in focus. A lens can only precisely focus on one plane at a time. However, there’s always a certain amount of the picture in front of, and behind, this plane that also appears to be sharp.

It is this zone of ‘acceptable sharpness’ that is the depth of field. Anything outside of this zone appears blurred or out of focus. The amount of depth of field varies from picture to picture, depending on a number of different factors.

How does knowing this help to improve my shots?
Depth of field is one of the most important creative controls available to the photographer. By learning how to control it, you can ensure that everything from your feet to the horizon appears pin sharp.

Alternatively, you can make sure that depth of field is restricted to such an extent that parts of your picture are thrown anonymously out of focus, for artistic effect or to hide distracting features in a scene.

So what’s the dark secret, then?
It’s not just one factor that affects the amount of depth of field that you end up with, but several working in tandem. Some of these factors, however, are much easier for photographers to control than the others.

What’s the easiest way to control depth of field?
The aperture setting you use is the simplest and most straightforward way of altering depth of field because you can do this without changing equipment or shooting position.

The smaller the aperture you set, the more depth of field you get and the more of your shot appears in focus. So on a typical zoom, a narrow aperture of f/22 will keep more of the shot in focus than a wider aperture of f/5.6.

The aperture can easily be altered by the photographer in a number of exposure modes, including Shutter Priority and Aperture Priority.

So I can set the depth of field precisely for every shot?
Yes and no. You can increase and decrease the amount of depth of field by adjusting the aperture. However, you don’t always have a free choice, because changing the aperture will affect the shutter speed, and some shutter speeds will not suit every situation.

Slow shutter speeds will cause moving subjects to appear blurred, for instance, or will create visible camera shake. More importantly, you only have a limited range of apertures, so often you can’t set the zone of sharpness precisely to suit your needs. But using the other factors can give you more control…

PAGE 1: Common questions about shallow and deep depth of field (1-5)
PAGE 2: Common questions about shallow and deep depth of field (6-10)
PAGE 3: Learning the lingo around depth of field

Photography basics: how to add depth to your photos

jmeyer — Mon, 17 Dec 2012 11:41:15 +0000

Understanding the principles of perspective is one of the photography basics that everyone learns starting out, but even for more experienced photographers it’s worthwhile to revisit this technique to find new creative photo ideas to enhance your images and add a sense of depth.

Through a variety of camera tricks and techniques you’ll be able to take control of your picture taking. Your choice of lens, aperture settings and your point of view are just some of the factors that can dramatically alter the illusion of depth that appears in your images – master these photography basics and you’ll be well on your way to creating dynamic images.

What is Depth of Field?

Depth of field is the term used to describe the areas before and beyond the point of focus that also appear sharp. You can control how large this area is through your choice of aperture and lens. An image can be totally transformed by using a wide aperture such as f/2.8, which will throw a boring or messy background out of focus.

Shallow depth of field

Shallow depth of field
This image of some berries shows how opening up the aperture to its widest setting of f/2.8 and focusing on the bunch to the right has thrown the background out of focus and created a shallow depth of field. This makes the berries really jump out from the scene.

Deep depth of field

Deep depth of field
By focusing on the same cluster of berries but closing the aperture down to f/20, a greater depth of field is created and the focal point has become lost in the background. One of the photography basics for landscape photographers, this technique can be used to effectively draw subjects together on the same focal plane.

PAGE 1: What is depth of field?
PAGE 2: Perspective and the focal length
PAGE 3: Using a long lens
PAGE 4: Change the focal plane

Photoshop Lens Blur: take precise control over depth of field post-shoot

jmeyer — Thu, 08 Nov 2012 12:00:30 +0000

When shooting a small object up close, you can adjust your lens’s focal point manually so that your subject’s key details look sharp, while the rest of the features gradually soften into a delicate lens-induced blur (or bokeh). This bokeh effect can enhance an image by creating an abstract background blur that complements colours and details in sharper areas and draws attention to a specific part of the shot.

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.

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

Shoot Like a Pro: master depth of field in outdoor portraits

jmeyer — Mon, 10 Sep 2012 02:00:33 +0000

Whether you choose to blur it or keep it sharp, an attractive background is key to successful outdoor portraits. In the second part of our Shoot Like A Pro series on outdoor portrait photography we show you how to take control of depth of field…

The amount of an image that appears sharp from the front to the back is key to its look and feel.

Using a shallow depth of field, where only a small part of a portrait is in focus, concentrates most of the viewer’s attention on the sharp areas, while deliberately keeping more of the scene sharp makes the subject’s surroundings more visible.

As there are three things that determine the depth of field in your shots – aperture, focal length and your distance from the subject – it can take practice to get the effect you want. Here’s how these key factors affect your shots…

Aperture
One of the easiest ways to control the depth of field is to change the aperture that you use. For shallow depth of field, choose a wide aperture (small f-number) such as f/2.8 or f/4.

To capture more of the scene in sharp focus, use a smaller aperture (larger f-number), such as f/11 or f/16.

Prime lenses offering wide apertures (such as a 50mm f/1.8) produce a really shallow depth of field, which makes them the perfect lens for portraits.

Focal length
If the other settings stay the same, a longer focal length lens will blur the background more than a shorter one. Try selecting a focal length of around 55-70mm in order to throw backgrounds out of focus.

Shooting distance
The final thing governing the depth of field of your shots is how far you are standing from the subject. The further you are from your subject, the more of the shot will be in focus from front to back, while the closer you are the less of it will be sharp.

Using an 85mm lens and an aperture of f/2 has produced shallow depth of field

This means you’ll find it easier to get shallow depth of field by getting as close as you can.

How far you are from the subject will be governed by the focal length of the lens you are using, and how much of the subject you want to include.

With the same lens and aperture settings, simply getting closer has reduced the depth of field

It’s much easier to get shallow depth of field effects when shooting head-and-shoulder (or close-up) images than it is if you’re taking full-length portraits.

But remember that it’s also easier to get shallow depth of field with a longer focal length lens, and you’ll also produce unflattering distortion if you get too close to the subject.

Best Focus Modes For Outdoor Portraits
With most portraits it’s essential that at least one of the eyes is sharp, and when using shallow depth of field it’s critical that you focus accurately on this area.

As long as the subject is static, you can use either manual or automatic focus modes to good effect. Using autofocus you should select single or one-shot mode, so that you can lock the setting by half-pressing the shutter release to focus on the eyes.

For moving subjects, you should set the camera to servo or continuous autofocus. Then the camera can track the subject, although when combined with a shallow depth of field it can be difficult to get pin-sharp focus on a moving subject.

For the best results, select the focus point you want to use, so that it corresponds to where the subject’s eyes are in the frame. This will save you time compared to using the central focusing point and reframing your shot.

READ THE REST OF OUR OUTDOOR PORTRAIT PHOTOGRAPHY SERIES

Outdoor portrait photography made easy
The best lenses for outdoor portrait photography
Essential flash techniques for outdoor portraits

Background Blur: how to fake a shallow depth of field in 15 minutes

jmeyer — Wed, 05 Sep 2012 02:00:06 +0000

When shooting a portrait you can flatter your subject by switching the camera to Portrait mode. This opens up the lens’s aperture to a wide value such as f/4.5. As a result of this wide aperture value the subject’s face will look nice and sharp, while allowing you to blur background and foreground details.

When capturing a wider shot of your subject, you’ll need to step back or zoom out to fit them into the frame.

However, if you use the same wide aperture setting it can be more difficult to get the person looking sharp while keeping the background blurred.

You’ll also get less background blur when shooting while zoomed out, allowing the eye to become distracted by background detail.

In this Photoshop Elements tutorial we’ll show you how to take control of your shot’s bokeh (background blur), so you can hide distracting details and draw the eye to your main subject.

We’ll show you how to create a realistic background blur by using the Selection Brush to isolate particular regions and then masks to stop the rest of the frame from blurring.

This enables you to apply different blur amounts to specific areas depending on their distance from the lens, mimicking the look of a lens-induced bokeh effect.

You’ll also learn how to use masks to control the behaviour of Adjustment Layers, so you can target and reduce the intensity of the distracting specular highlights without adjusting the exposure in the rest of the shot.

Our original image

CLICK HERE TO GET STARTED