Archivi categoria: aperture

Famous South African Photographer Found Guilty of Murdering Sex Worker

Well-known South African photographer Zwelethu Mthethwa has been found guilty of murdering a sex worker in a suburb of Cape Town, South Africa, in 2013.

Mthethwa received a Fulbright Scholarship to the Rochester Institute of Technology, where he received his master’s degree in imaging arts in 1989. He is among South Africa’s most famous artists and has had 35 solo exhibitions internationally. His works have been shown at important institutions around the world, including the Museum of Modern Art and the International Centre of Photography, New York; the Victoria & Albert Museum, London; the Centre Pompidou, Paris; and at the Venice Biennale. Mthethwa is represented by Jack Shainman Gallery in the Chelsea neighborhood of New York City.

During the trial, the prosecution presented CCTV footage linking Mthethwa to the crime scene. The footage shows the artist’s black Porsche pulling up next to 23-year-old Nokuphila Kumalo. The driver is then seen exiting the car and attacking the young woman. He killed her “by repeatedly kicking her and stomping her body with booted feet,” said the indictment. Mthethwa argued that it was not him in the video‚ and called on “gait” experts to testify that the manner in which the attacker walked did not match his style of walking. However, Judge Patricia Goliath stated in her ruling that the video furnished a “silent witness.”

Women’s rights activists rallied outside the courthouse over the course of the lengthy trial with one placard reading, “Sex workers are not your Art”.

Hugs after the guilty verdict (left), and protesters outside the courtroom (right). Photos by SWEAT.
Photo by SWEAT.

Mthethwa uses environmental portraiture, often taken in quiet domestic settings, to explore the life of migrants, farmers and miners in post-apartheid South Africa. He told PDN that in photographing marginalized South Africans in their homes, “I really wanted to empower the people.”

ArtNet reports that Mthetwas’s bail has been revoked while he awaits sentencing on March 29, 2017.


Image credits: Header photo by SWEAT.

Famous South African Photographer Found Guilty of Murdering Sex Worker

Well-known South African photographer Zwelethu Mthethwa has been found guilty of murdering a sex worker in a suburb of Cape Town, South Africa, in 2013.

Mthethwa received a Fulbright Scholarship to the Rochester Institute of Technology, where he received his master’s degree in imaging arts in 1989. He is among South Africa’s most famous artists and has had 35 solo exhibitions internationally. His works have been shown at important institutions around the world, including the Museum of Modern Art and the International Centre of Photography, New York; the Victoria & Albert Museum, London; the Centre Pompidou, Paris; and at the Venice Biennale. Mthethwa is represented by Jack Shainman Gallery in the Chelsea neighborhood of New York City.

During the trial, the prosecution presented CCTV footage linking Mthethwa to the crime scene. The footage shows the artist’s black Porsche pulling up next to 23-year-old Nokuphila Kumalo. The driver is then seen exiting the car and attacking the young woman. He killed her “by repeatedly kicking her and stomping her body with booted feet,” said the indictment. Mthethwa argued that it was not him in the video‚ and called on “gait” experts to testify that the manner in which the attacker walked did not match his style of walking. However, Judge Patricia Goliath stated in her ruling that the video furnished a “silent witness.”

Women’s rights activists rallied outside the courthouse over the course of the lengthy trial with one placard reading, “Sex workers are not your Art”.

Hugs after the guilty verdict (left), and protesters outside the courtroom (right). Photos by SWEAT.
Photo by SWEAT.

Mthethwa uses environmental portraiture, often taken in quiet domestic settings, to explore the life of migrants, farmers and miners in post-apartheid South Africa. He told PDN that in photographing marginalized South Africans in their homes, “I really wanted to empower the people.”

ArtNet reports that Mthetwas’s bail has been revoked while he awaits sentencing on March 29, 2017.


Image credits: Header photo by SWEAT.

F-Stops vs T-Stops: The Difference Explained in Plain English

Ever wonder what the difference between an F-Stop and a T-Stop is? If you’ve never bothered to look up and understand this bit of light transmission trivia, listen up: this simple video does the work for you.

The video was created by YouTuber wolfcrow, who does a fantastic job explaining the difference between the F (which stands for ‘focal length’) and T (which stands for ‘transmission’) numbers. You should check out the video if you want to hear the full explanation, but the basics are as follows:

The F-Stop is a theoretical value, while the T-Stop is an actual tested value. So while both the Zeiss Otus 55mm f/1.4 and 85mm f/1.4 lenses have a wide-open F-Number of 1.4, they actually transmit different values. According to DxOMark’s tests, the 55mm Otus transmission is T1.5 while the 85mm Otus transmission is T1.7.

Same F-Stop, Different T-Stops
Same F-Stop, Different T-Stops

Which brings us to the question you’re probably asking yourself right now: why do most photography lenses use F-Stop and cinema lenses use T-Stop? Wolfcrow explains this as well.

According to him, there are three reasons photography lens manufacturers don’t bother with T-Stops:

  1. In-camera light metering will compensate for the minor exposure difference between two different lenses with the same F-Stop but different T-Stops.
  2. The biggest transmission difference you’ll get is about 1/3 of a stop, which is no problem to fix in post-processing.
  3. T-Stop testing every new lens is expensive and time consuming; because of reasons 1 and 2, it’s not worth the investment for photography lenses.

Cinematography, on the other hand, is more complicated. Multiple scenes, sometimes captured on multiple days, and often consisting of multiple angles shot with multiple lenses means correcting exposure in post can be expensive. Plus, even if new tech means all you’re saving is minutes per day, those minutes can cost thousands on a huge production.

Modern camera technology makes F-Stops a viable option for today’s filmmakers, but the top cinema lenses still guarantee the real-world exposure of T-Stops.

tstop1

And there you have it. Check out the video up top to see these concepts explained visually, and if you want to take a deeper dive into aperture and f-stops, click here.

(via ISO 1200)

A Comprehensive Beginner’s Guide to Aperture, Shutter Speed, and ISO

pyramid

This guide to photographic exposure aims to help you take full control of your camera. I often tell my students that I want them to move away from the idea “taking a photograph” and towards the idea of “making a photograph.” I teach them how to take the camera off auto mode and take full control of the settings themselves in order to create the photograph they want.

Why let the camera decide these things for you? Do you let your mother choose your clothes? Maybe some of you do, I don’t know. Frankly, I don’t want to know.

I hope to do the same for the readers of this tutorial. I want you take control of your camera. In order to do this, it’s essential to understand the 3 components of what we call “The Exposure Triangle”. These are: aperture, shutter speed and ISO. By the end of this tutorial, you should understand what these 3 components are and how they affect the final photograph. You will also learn how to use the 3 main shooting modes on your camera: aperture priority, shutter priority and manual. Finally, I’ll explain how to decide which settings to choose as you prepare to shoot a scene.

What is exposure?

First of all we need to define what we mean by exposure. Exposure refers to the amount of light that enters the camera and hits the digital sensor. Basically, it is a measure of how dark or bright a photograph is.

If the image is too bright, it is overexposed. Too much light has been allowed to hit the sensor. If it is too dark, it is underexposed. Not enough light has been allowed to hit the sensor. We can control how much light reaches the sensor by changing the aperture, shutter speed and ISO settings.

Exposure is measured in ‘stops’. For example, if you find that your photo has turned out too dark (underexposed), you may increase your exposure by a ‘stop’ or two to make it brighter. Conversely, if the image is overexposed, you may need to decrease the exposure by a stop or two. There is no such thing as the ‘perfect’ exposure, only the right exposure for the photograph you are creating. Some photos such as night shots are supposed to be dark while photos taken in the snow for example are supposed to be bright.

Measuring exposure using a histogram

All digital cameras allow you to see a visual representation of exposure using the histogram. Check your camera’s manual to find out how to turn on the histogram feature. There was a member of my photography club who would tell all new members to RTFM. This stood for ‘Read the Manual’. I’ll let you figure out what the ‘f’ stood for yourself.

The histogram is a graph that represents the spread of tones in a photograph, from the shadows, to the mid tones to the highlights. It allows you to check if the photograph has any shadows that are too dark or ‘clipped’ and to see if you have any highlights that are too bright or ‘blown out’.

Clipped shadows are areas of pure black and contain no detail. Blown out highlights are areas of pure white and also contain no detail. Very generally speaking, you will want to avoid both of these. That said, I personally don’t mind a little clipping in the shadows as it adds punch to the image.

If you look at the histogram below, you will see that some of the graph is right up against the left hand axis of the graph. This means that some of the shadows are clipped. If you look at the right, you will see that a very tiny amount of highlights have been blown out as a very small part of the graph is up against the right hand edge. Sometimes this is unavoidable for example with street lights or if the sun in the frame. Remember, that the histogram is only a guide.

histogram

Examples of underexposed and overexposed photographs

Below we have examples of an underexposed photo, an overexposed photo and a correctly exposed photo.

under

Underexposed photograph: This photograph is underexposed by about 3 stops. You can see that the histogram is completely bunched up to the left as a result. There are lots of clipped shadows on the underside of the gondolas.

over

Overexposed photograph: This image is overexposed by about 3 stops and as you can see, the histogram is bunched up to the right as a result. There are a lot of clipped highlights is this photo. In fact, the entire sky is pure white and contains no detail whatsoever.

correct

Correctly exposed photograph: The photo above has the right exposure for the scene in question. You can see on the histogram that there is a good spread of shadows, mid-tones and highlights. It’s quite a bright image as you can see from the fact that the graph spikes on the right of the graph.

There is a little clipping in the shadows which I don’t mind as it adds some punch to the shot. As you can see from the right hand side of the graph, there are some very bright areas but the highlights are not blown out.

Using the highlights warning feature on your camera

It’s always a good idea to check the histogram after you’ve taken a shot in order to prevent too many clipped shadows and blown out highlights. Most digital cameras also have a ‘highlight warning’ feature.

This makes areas of the image that have blown highlights flash on your screen. It’s an incredibly useful feature and I keep it turned on all the time. Below, you can see how the highlight warning looks on the overexposed gondola photo. A huge amount of the photo is flashing because so many of the highlights have been blown out.

What is aperture?

lens-aperture

The aperture refers to the size of the opening in the lens through which the light enters the camera. The size of this opening can be adjusted and the aperture size is measured in f-stops. The image on the right shows you exactly what the aperture on a lens looks like.

When you change the f-stop value, you change the size of the opening. Here’s the weird thing though. The higher the f-stop, the smaller the opening.

Take a look at the chart below to see what different apertures look like at different f-stops. On the far left, you can see that setting an aperture of f16 will result in a small opening. Choosing an aperture of f1.4 will result in a very wide opening.

aperture-chart

How does your choice of aperture affect the photograph?

The most noticeable effect your choice of aperture has on the photograph is the depth of field. What do we mean by this exactly? In very simple terms, depth of field refers to the amount of the image that is sharp. What does this mean in practice?

If you use a wide aperture, the depth of field will be shallow. Only part of the image is sharp and the rest will be out of focus or blurred. Look at the picture on the left below. The cat is perfectly sharp but the background is blurred. Using a wide aperture works well for portrait style photographs as it makes the subject of the shot really stand out against the blurred background.

depth-of-field-diagram

In this case, the depth of field extends from about the tip of the cat’s nose to just behind its head, no more than a few centimeters (from point A to point B in the diagram). Anything not in this range, either in front of it or behind will not be sharp. For this shot, I used a wide aperture of f/3.5.

OLYMPUS DIGITAL CAMERA

When you use a narrow aperture, the depth of field is deep. When the depth of field is deep, all of the photograph from foreground to background is sharp.

Take a look at the photo below taken in the Dublin Docklands. Everything from the dock cleat in the foreground to the bridge in the background is sharp. In this case the depth of field is several hundred metres, extending right from the foreground to the background of the scene. In this case, I used a narrower aperture of f/11.

samuel-beckett-bridge-at-sunset-dublin

Most of the time, we want to achieve a deep depth of field when shooting landscapes. We want all of the image to be pin sharp.

The mid range apertures (around f/8) are good for shooting handheld for example when doing street photography. You get a good balance between having enough depth of field and fast enough shutter speeds to shoot hand held. We’ll discuss shutter speeds in more detail later.

The chart below gives you a good idea how different apertures will affect the depth of field in your photographs. You can see that as the aperture gets wider, the pyramid in the background becomes more blurred.

aperture-effect-chart-2

What is shutter speed?

The shutter speed refers to the length of time the opening in the lens remains open to let light into the camera and onto the sensor. The shutter speed can be as fast as 1/10,000 of a second or as slow as several minutes.

How does your choice of shutter speed affect the photograph?

Fast shutter speeds have the effect of freezing motion in the scene you are photographing. Conversely, slow shutter speeds will blur motion in a scene. Both of these can be used to great creative effect.

The shutter speed settings on your camera provide a great way to experiment with capturing motion in your landscape photography. This is especially the case with moving water.

OLYMPUS DIGITAL CAMERA

fishing-boat-at-sunset-tunisia

By using a slow shutter speed (1/2 second), we can blur the water in a waterfall for example and create a sense of motion even though it’s a still image. You can see this in this photo of a waterfall in Ireland above. When working with slow shutter speeds, it is essential to use a tripod otherwise camera shake will result in a completely blurred photo.

In the second photograph taken in Tunisia, I used an extremely long shutter speed of 160 seconds. To achieve this, I used a 10 stop neutral density filter. This reduced the light entering the camera down to 1/1000th of what it would be without the filter. This, in turn, allowed me to set such a long exposure time.

As you can see, the clouds moved across the sky during the almost 3 minutes it took to take the photo resulting in the blurred effect.

You can also use fast shutter speeds to freeze motion like in this black and white seascape below.

atlantic-coast-donegal-ireland

For this photograph, I wanted to freeze the motion of the waves crashing against the shore. A fast shutter speed of 1/320th of a second ensured that the wave seems to ‘freeze’ in time. Landscapes that include moving water afford great opportunities to experiment with different exposure times.

The chart below shows how different shutter speeds would effect the sense of motion if you were photographing a person running. Fast shutter speeds will freeze the motion. This technique is often used in sports photography. The slower the shutter speed becomes, the more blurred the person running becomes in the photograph.

shutter-speed-effect-chart

How do you know if your shutter speed is fast enough to shoot handheld?

There is a very simple trick to check if your shutter speed is fast enough to shoot hand held. Simply look at the focal length you have zoomed in to on the lens.

On the lens below, the focal length is set at about 30mm. In this case I simply multiply the focal length by 2 and divide it into 1 to get the minimum shutter speed required to shoot hand held. So, 30 x 2 is 60 therefore the minimum shutter speed required to shoot hand held is 1/60 of a second.

camera-lens-focal-length

This means that you can get away with using slower shutter speeds when the angle is wider. It’s obviously harder to keep the camera steady when zooming in. Think of how difficult it is to keep your sights on an object when using binoculars. It’s the same principle.

If you find that the light is low and you can’t get a fast enough shutter speed, you can increase the ISO. In the next section, I’ll explain what ISO is and how it effects the photograph.

What is ISO?

The ISO refers to how sensitive the digital sensor in your camera is to light. The lower the ISO number, the less sensitive it is to light. Setting a higher ISO number increases the sensitivity of your camera sensor to light. Most cameras have ISOs ranging from about 50 or 100 ISO right up to 16,000 ISO or higher.

How does your choice of ISO affect the photograph?

As you increase the ISO value, your camera sensor becomes more sensitive to light. This means that you can achieve higher shutter speeds. This can be extremely useful when shooting in low light without a tripod. You may find that shooting at 100 ISO results in shutter speeds that are too slow to hand hold without camera shake. By increasing the ISO to 800 ISO for example, you may find that your shutter speed is now fast enough to hand hold.

You may be wondering: why not just use a really high ISO every time to ensure a sharp photo? The problem is that there is a trade off when it comes to image quality. The higher the ISO used, the more digital noise will be present in the image. Digital noise results in a graininess that can have a negative effect on image quality. Take a look at the labels of this bottle of wine shot at different ISOs.

The first one was shot at 100 ISO.

iso100

The second photo was shot at a very high ISO 3200. You can see that the graininess has degraded the image quality quite a lot.

iso3200

When I finished taking these shots of the bottle of wine, I of course sampled the contents. I… eh… wanted to learn about French culture. Funnily enough, after I finished the bottle, the image quality from my own eyes degraded somewhat.

The chart below illustrates the effect of ISO on image quality.

iso-effect-chart-1

This does not mean that you should not increase your ISO when the need arises. The example of ISO 3200 above is quite extreme. Most of the newer cameras actually handle higher ISOs very well and retain high image quality. I know that in low light conditions, I prefer to increase my ISO a little to avoid camera shake even it it means a little graininess. It’s usually not enough to seriously degrade the image quality though.

Next, we’re going to take a look at how to actually set the aperture and shutter speed in your camera. There are 3 modes you can use: aperture priority, shutter priority and manual.

How to use Aperture Priority Mode on your camera

aperture-priority

Aperture priority mode is a semi-manual mode. When using this mode, you choose the aperture you want and the camera chooses an appropriate shutter speed in order to achieve a correctly exposed photo. To switch your camera to aperture priority, turn the dial on top of your camera to ‘A’.

This is actually the shooting mode I use 90% of the time when shooting urban landscapes. I usually choose an aperture of around f16 to ensure maximum depth of field and then let the camera choose the correct shutter speed. As I usually use a tripod, I am generally not too concerned about the shutter speed being too slow.

If I am shooting hand held, I always keep an eye on the shutter speed the camera has chosen just to make sure it isn’t too slow. If it is too slow, I use a wider aperture which will give a faster shutter speed as the opening is larger and lets the light in faster. I also have the option of increasing the ISO to get a faster shutter speed.

How to use Shutter Priority Mode on your camera

shutter-priority

Shutter priority is basically the opposite to aperture priority. You set the shutter speed you want and the camera sets the aperture. To switch your camera to shutter priority, turn the dial on top of your camera to ‘S’. On Canon models, this mode is actually called “Tv” mode which stands for “time value”.

I personally don’t use this mode too often. It can be useful if you need to set a minimum shutter speed in order to avoid camera shake. You may also want a specific longer shutter speed in order to create motion blur. I tend to use manual mode in this case as it gives me greater control over the shutter speed and aperture together. More on manual mode later.

How to use the Exposure Compensation feature on your camera

exposure-compensation-button

Sometimes when you use aperture or shutter priority modes, you may find that your images are too bright or too dark. Sometimes the lighting conditions may confuse the camera and it results in the image being underexposed or overexposed. Thankfully, there is a way of fixing this. It’s called exposure compensation. To switch this on, press the button with the plus/minus symbols.

This will bring up a chart that goes from -5 to +5. Sometimes these numbers are different and may only range from -3 to +3 depending on the camera. This chart represents the exposure of your photograph. So how does it work?

When you are using aperture priority mode for example, the camera will set a shutter speed that makes the camera expose at the “0” point of this chart, right in the middle. In theory, this should be the correct exposure. In reality though, this is not always the case. As we said, some photos are supposed to be bright and others are supposed to be dark.

If you find that your photo is too bright or overexposed, you simply dial down the exposure by a stop or whatever you think is needed. When you turn the dial to the left (RTFM to see which dial), you can set the exposure at -1 for example. This will make the photograph 1 stop darker. When you turn the dial to the right, you can make the photo brighter. You may need to experiment a little to get the exposure you want.

exposure-compensation

How does exposure compensation work exactly? If you are using aperture priority mode and dial the exposure down 2 stops for example, the aperture will stay the same but the shutter speed will change to a faster speed so that less light enters the camera and the picture is made darker.

The opposite happens when you dial up the exposure. The aperture stays the same but the shutter speed will get longer to let more light in and make the image brighter. As already mentioned, keep an eye on the shutter speed if you are shooting hand held. Don’t allow it to become too slow in order to avoid camera shake.

Exposure compensation works in the same way when using shutter priority mode except that the shutter speed will stay the same and the aperture will be changed by the camera accordingly.

How to use Manual Mode on your camera

manual-mode

Here comes the scary one: manual mode! When you set the camera to manual mode, you set both the aperture and shutter speed. How do you know what combination to use to ensure the right exposure? It’s actually quite easy. When you switch to manual mode on the dial (M), you again see an exposure chart that is exactly the same as the exposure compensation chart.

You then turn the aperture and shutter speed dials until the exposure is set to 0. Check your manual to see which dials to use.

Here is an example of how I might use manual mode when shooting a landscape:

  1. I decide what aperture I want to use. If it’s a landscape, I might pick an aperture of about f/16 to ensure plenty of depth of field. After all, I want everything to be sharp from the foreground to the background. I turn the aperture dial until, the aperture is set to f/16.
  2. I then turn the shutter speed dial until the marker on the exposure chart is at zero. This in theory should mean that I now have the correct combination of aperture and shutter speed to ensure the right exposure.
  3. I then check that I am happy with both the aperture and shutter speed and make some adjustments if necessary.
  4. If I find that the shot is too bright or too dark I retake it after moving the dial to either minus a stop or plus a stop (or more as the case may be). The ‘right’ exposure may not always be at the “0” point in the middle. As I have said a few times now, some photos are supposed to be bright or dark.

How do I decide which settings to use in manual mode?

This is where your own creativity comes in to play. I usually decide which is the most important element in the photo and set this first.

As I mainly shoot urban landscape photos, this means I usually set the aperture first as ensuring plenty of depth of field is my biggest concern. I then set the shutter speed. It’s basically a balancing act and with practice you will gain an intuition for what settings you need to achieve the vision you have for a particular photograph.

What if the highlights are blown out or the shadows are clipped no matter what settings I use?

Sometimes the contrast in a scene is simply too much for your camera to handle no matter which combination of aperture and shutter speed you use. In this case, bracketing can be used to solve the problem.

When I bracket a photo, I usually take 3 photos of the same scene, one with the exposure set to “0”, another deliberately underexposed by 2 stops and a final one deliberately overexposed by 2 stops. I can then combine these these in post-processing to get the ‘perfect’ exposure. There are several methods of doing this which I will cover in a future tutorial.

In the example below, I took 3 exposures of the Charles Bridge in Prague and blended them in post production to produce a single photograph with plenty of detail in all areas of the frame.

exposurebracketing

exposure-blending-example

The final photograph is a blend of all 3 images, leading to plenty of detail throughout the image. There are also no clipped shadows or blown out highlights. As you can see, I also cropped the final image to create a better composition.


I hope that after reading this tutorial that you will be confident to take your camera off auto mode and take control of the settings yourself. In this way, you can move from merely taking a photography to making a photograph. Don’t be afraid to experiment with all of the settings you have just learnt about. Over time, you won’t even have to think too much about the settings.

I often advise students to go on a photo shoot where they specifically experiment with different apertures, another to experiment with shutter speed and so on.


About the author: Barry O Carroll is a Dublin, Ireland-based photographer specializing in landscape photography with a particular emphasis on urban landscapes, street scenes and architecture photography. You can find more of his work on his website or by following him on Facebook and Twitter. This article was also published here.

Depth of Field Explained

3 pour 10 / 3 for 10

When you focus your camera, the area around the focal distance will also be in focus. But this can fall of to blur quickly, or slowly. The acceptable amount of in focus area around what’s you are focusing on is called Depth of Field.

Depth of field can be an easy concept to understand, but practicing it isn’t always straightforward. Which aperture you choose, which lens you use, what camera you are shooting with and even how close something is to your lens all play a large part of controlling Depth of Field. Throughout this post, the guys from Aperture Photo Tours in Paris, London, and Venice will be exploring all the elements that make up Depth of Field and how to take control of your camera.

Terminology

Firstly let’s talk through some of the terminology so we understand all of the vocabulary related to Depth of Field. Some of them sound similar, but have very different meanings, we want to make sure we’re all on the same page.

  • Depth of Field: The distance between the closest and furthest points in an image that are in ‘acceptable focus’.
  • Narrow (or shallow, or small) Depth of Field: To have a shorter Depth of Field. To have a small amount of the image in focus.
  • Wide (or deep, or large) Depth of Field: To have a larger Depth of Field. To have a large amount of the image in focus.
  • Bokeh: The blur aesthetic caused by an object lying outside of the Depth of Field.
  • Focal length: How wide or telephoto yours lens is. Eg. 24mm, 50mm or 200mm.
  • Focal distance: The distance you select on your lens. Eg. 50cm, 1m, 5m.
  • Infinity ∞: The maximum focus distance on your lens.
  • Hyperfocal: The closest distance where everything from this point until infinity will be in focus.
  • Maximum aperture: The largest aperture (smallest number) on your lens. Eg. f/1.4, f/2.8, f4 depending on your lens.
  • Minimum aperture: The smallest aperture (largest number) of your lens. Eg. f/22 or f/29 depending on your lens.
  • Prime lens: A lens of fixed focal length. A lens that doesn’t zoom. Eg. Nikon 50mm f/1.4 AF-S ED G lens.
Nikon D200 and NIKKOR 24mm f/2.8 @ f/22, 1/30sec, and ISO 100.
Nikon D200 and NIKKOR 24mm f/2.8 @ f/22, 1/30sec, and ISO 100.

Why Depth of Field is important?

When you are shooting, Depth of Field can play a large factor in how your image will be rendered and can change the meaning and intention of the image. You can choose to selectively isolate a subject from its background by having a narrow Depth of Field or alternatively you can make sure that everything from the foreground to infinity will be in focus, insuring you have a sharp image throughout your image.

When and why you decide to choose these settings will be up to you, but some examples would be:

  • Using a narrow Depth of Field in a portrait to separate the subject from its background.
  • Using a narrow Depth of Field to de clutter a background and focus on the foreground of an image.
  • Using a wide Depth of Field in landscape shots to ensure everything is in focus.
  • Using a wide Depth of Field when shooting through a frame to insure both the frame and the subject are in focus.
f/1.4 – Infinity in focus, trees and flowers out of focus.
f/1.4 – Infinity in focus, trees and flowers out of focus.
f/16 – Foreground, middle, and infinity are all in focus.
f/16 – Foreground, middle, and infinity are all in focus.
f/22 – Cluttered, no separation of background and foreground.
f/22 – Cluttered, no separation of foreground and background.
f/2.8 – Uncluttered, separation of foreground and background.
f/2.8 – Uncluttered, separation of foreground and background.

Aperture and Depth of Field

One of the most obvious factors to controlling Depth of Field is the aperture. When you have a smaller aperture (larger number) you will have a wide Depth of Field. In this instant you will have a greater distance between the closest and furthest points in an image.

When you have a larger aperture (smaller number) you will have a narrower Depth of Field. The blurry parts that are not in focus is called Bokeh, and many people are quite a fan of the way it will render light.

f/1.4 – 1/640sec, ISO 100
f/1.4 – 1/640sec, ISO 100
f/5.6 – 1/30sec, ISO 100
f/5.6 – 1/30sec, ISO 100
f/16 – 1/4sec, ISO 100
f/16 – 1/4sec, ISO 100

Focal length and Distance Compression

Even though your depth of field in actual terms will be relatively the same at 24mm as 80mm and again as 200mm, the image will appear to be more out of focus when zoomed in. The reason for this is caused by ‘distance compression’; as we walk back and zoom in, keeping our subject the same size within the frame, the background has been brought closer.

Look at the example below; the chair has relatively the same amount of blur in each photo, but as we compress the background and make it closer to the image, it gives the impression of being more out of focus, by amplifying the out of focus area in comparison to our subject.

If, by instance, your subject and background were both in focus in the 24mm image, they would still be in focus in the 200mm image as well. Only when it is out of focus can you amplify the effect.

Photo taken with a Nikon D7000 and NIKKOR 24-70MM f/2.8 & NIKKOR 70-200MM f/2.8 @ f/4, 1/800, and ISO 100. Left: 200mm f/4 | Middle: 70mm f/4 | Right: 24mm f/4.
Photo taken with a Nikon D7000 and Nikkor 24-70mm f/2.8 & 70-200mm f/2.8 @ f/4, 1/800, and ISO 100.
Left: 200mm f/4 | Middle: 70mm f/4 | Right: 24mm f/4.

The wider your lens is, the wider your Depth of Field will be. On my 8mm f/3.5 lens for example, I can sit on f/5.6 and my hyperfocal distance is about 50cm, meaning everything from half a meter to infinity will be completely in focus. It can therefore be more difficult to have a shallow Depth of Field on a wider lens.

At f/22 on my 8mm Samyang lens the depth of field extends from 10cm to infinity.
At f/22 on my 8mm Samyang lens the depth of field extends from 10cm to infinity.

Focus distance and Depth of Field

The focus barrel in your lens increases exponentially. Each lens is different, but take this example of a 50mm lens below. If we imagine the Depth of Field as being a fixed width on this exponential scale we can see that the further towards infinity, the larger the Depth of Field will become, without changing the aperture or focal length of your lens.

As you can see from the chart, at f/22 the depth of field is from 3m to infinity when the focus is set to 6m. But when the focus is set to 1m, still at f/22, the depth of field is now only from 85cm to 1.2m. When you bring the focus to 0.6m, the depth of field is now only from 55cm to 68cm.

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But when you have the aperture set to f/2.8 the distance between the two points drastically reduces. When you are shooting a subject 60cm from the camera, the depth of field is only 4cm, as opposed to 1.3m when you were shooting at f/22

If you want to have a narrow Depth of Field, bring your subject closer to the camera.

If you want to have a deep depth of field, move your subject further away from the camera.

Hyperfocal

Because the Depth of Field is a fixed width on an exponential focal plane inherently you will get approximately ⅓ of the distance in front of the focal point in focus and ⅔ of the distance behind the focal point in focus. If you know exactly how much distance you have in front and behind you can focus slightly in front of the focal point, or slightly behind to increase or decrease the Depth of Field in an image.

For example, if you wanted to maximise your Depth of Field to include infinity, you can focus forward of infinity to include infinity at the end of your Depth of Field, not in the middle and bring closer your hyperfocal distance. Without same 50mm example from before, you can set you camera at 30m at f/2.8 and get everything from 15m to infinity in focus. At f/8 if you set the focus to 10m everything from 5.1m until infinity would be in focus. At f/22 if you set your camera’s focus at 6m, everything from 3m to infinity would be in focus.

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It is for this reason that if you are shooting anything further than 15m on a 50mm lens, your aperture literally doesn’t affect depth of field. Anything beyond 15m has hit hyperfocal at all aperture stops and everything will be in focus.

On Photopills website is a really handy Depth of Field Calculator that will specify hyperfocal distances, as well as all other Depth of Field calculations.

Photo by William Lounsbury – Nikon D800 and NIKKOR 24-70mm f/2.8 @ 36MM, f/8, 1/500sec, and ISO 200.
Photo by William Lounsbury – Nikon D800 and NIKKOR 24-70mm f/2.8 @ 36MM, f/8, 1/500sec, and ISO 200.

Speed of lens

We often talk about the speed of a lens, or having a fast lens. When we are talking about this, we are talking about how large the aperture can open. Many versatile zoom lens will have a maximum aperture of f4 or f/5.6 which will make it difficult to get a real narrow Depth of Field.

A high quality zoom, and some prime lens will be “faster” and have a maximum aperture of f/2.8. We call them faster lens because when you can shoot at a larger aperture, you can increase the speed with the same amount of light.

A high quality prime lens, like a 35mm, 50mm or 85mm will go down as low as f/2 or even f/1.4 giving you remarkably thin Depth of Field. For a portrait shoot with a 50mm f/1.4 you can focus on the eyes, and have the tip of the nose and the ears already blurry.

There are some exceptional lens that are faster than f/1.4, going as fast as f/1 and even f/0.8, but these lens are very rare and specialist lens.

Photo by Margot Simonney – Nikon D700 and NIKKOR 35mm f/1.4 @ f/1.4, 1/200sec, and ISO 200.
Photo by Margot Simonney – Nikon D700 and NIKKOR 35mm f/1.4 @ f/1.4, 1/200sec, and ISO 200.

I have a f/3.5 to f/5.6 lens. What does this mean?

Some zoom lens have variable maximum aperture. Usually the maximum aperture is larger at the wider focal length, and smaller at the most telephoto length. So if your lens is a 24-105mm f/3.5 to f/5.6 is will mean at 24mm you can go as low as f/3.5 but when you are zoomed into 105mm, the largest aperture you can have will be f/5.6.

Photo by Anna Volpi – Nikon D700 and NIKKOR 70-210mm f/4-5.6 @ 78mm, f/4, 1/2500sec, and ISO 320.
Photo by Anna Volpi – Nikon D700 and NIKKOR 70-210mm f/4-5.6 @ 78mm, f/4, 1/2500sec, and ISO 320.

I really like shallow Depth of Field and bokeh, but I am not a millionaire, is there a good lens you could suggest?

Both Nikon and Canon have very high quality 35mm and 50mm f/1.8 for under US$200. The standard focal length means you will have the ability to shoot close, and get a narrow depth of field. Most lens won’t go as fast as f/1.8 and for only a few hundred dollars they should be a standard part of every photographer’s kit.

Note that the D Nikon AF Nikkor 50mm f/1.8D is manual focus only for the following cameras. D5500, D5300, D5200, D5100, D5000, D3300, D3200, D3100, D3000, D60, D40, D40x. For autofocus you will need to buy the US$220 Nikon AF-S Nikkor 50mm f/1.8G

Does sensor size change the Depth of Field?

This is a little bit of a tricky one. Yes… and no. The Depth of Field between two identical photos from a full-frame camera and a cropped camera would look the same. Where the blurry line is, is that a full-frame camera has more image in the shot. So to compensate you will need to bring objects closer, or zoom in to achieve the same ratio.

From what we have learnt before, we note that both bring images closer to the camera or zooming in will give a narrower Depth of Field, giving the impression that a full frame camera can produce narrower Depth of Field.

Nikon D700 and NIKKOR 85mm f/1.8 @ f/1.8, 1/1250sec, and ISO 100.
Nikon D700 and NIKKOR 85mm f/1.8 @ f/1.8, 1/1250sec, and ISO 100.
Photo by Anna Volpi – Nikon D300S and NIKKOR 50mm f/1.4 @ f/1.4, 1/5000sec, and ISO 200.
Photo by Anna Volpi – Nikon D300S and NIKKOR 50mm f/1.4 @ f/1.4, 1/5000sec, and ISO 200.

Easy tips

To increase your Depth of Field (make a larger Depth of Field, make more of your image in focus):

  • Use a smaller aperture (higher number) eg. f/16 or f/22
  • Use a wide angle lens. Eg. 14mm or 24mm
  • Have your subject further away from your camera.

To have a narrow (or small) Depth of Field:

  • Use a large aperture. Eg. F/1.4 or f/2.8
  • Zoom your lens in. Eg. 80mm or 200mm
  • Have your subject closer to the lens.

So hopefully you understand how to get great bokeh or to keep everything tack sharp now. Don’t be discourage if you need to reread this blog to set everything in your head. It will take time, and most importantly, practice.

Why not come on a photography tour with Aperture Tours in London, Paris, or Venice and learn with a professional photographer in a photogenic city.


About the author: Alexander J.E. Bradley is the founder of Aperture Tours (formally Paris Photography Tours) and heads up the tours in Paris. A professional photographer for over a decade Alexander enjoys shooting the surreal by mixing dreamlike qualities into his conceptual images.

You can find more photos and articles like this on the Aperture Tours website, or by following Aperture Tours on Facebook, Twitter, and Instagram. This post was originally published here.


Image credits: All photographs by Alexander J.E. Bradley unless otherwise credited. All photos used with permission.