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Understanding – , Speed, and ISO

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Understanding Exposure – Aperture, , and ISO

Photography Basics – Understanding Exposure, Aperture, Shutter Speed, and ISO Many think that understanding Exposure is the toughest aspect in photography. Several people may shy away from a DSLR because they have to understand some of the alien terms like Aperture, Shutter Speed, ISO, etc.

The reality is that understanding these key concepts is easy and fun.

It requires a bit more time and patience to understand it in depth. Aperture, Shutter Speed and ISO are the basic building blocks of photography. If you understand how each of them work together to get an optimal exposure, you will enjoy your photography to the fullest.

To make the see the way we see is the most difficult aspect in photography. But, as we understand more about the exposure, we will be able to make the camera see what we want it to see.

We all know that we see the world through our eyes with the help of . When there is absolutely no light, then we do not see anything. In a way, our eyes are exposed to light to form a picture in our brain through which we perceive/understand our world.

A is made when the lens (or eyes) bends the light onto the sensor (or brain) to form a photograph (or picture).

Exposure

Exposure, in simple terms, means how much time the camera sensor is exposedto the light to make a photograph.

The amount of light passing through the lens opening (Aperture) for a specified duration of time (Shutter Speed) for which the camera sensor is open is called the Exposure.

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Understanding Exposure – Aperture, Shutter Speed, and ISO

Exposure is essentially a combination of Aperture, Shutter Speed, and ISO. To keep the matters simple, let us concentrate only on Aperture and Shutter Speed and keep the ISO for later articles. Here is a simple equation for exposure:

Exposure = Aperture + Shutter Speed + ISO

We will go through each of these core concepts Aperture, Shutter Speed, and ISO in detail in the upcoming articles.

A properly exposed photograph will contain proper information and all the details that are present in the actual scene.

A ’s life is so much easier in today’s digital world due to histograms. You can see if the exposure is correct or not by looking at the histograms. However, the knowledge of exposure will enable you to achieve optimum exposures to fulfill the artistic needs and to achieve creative results.

Underexposure

If the amount of light passing through the lens opening for duration of time when the camera sensor is open is less than optimal, then it is called underexposure. The underexposed photograph will look darker than the real scene.

Underexposed usually lack details in the shadow regions resulting in the crushed blacks. The histogram of such photographs, show the distribution towards the left most side with some clipped blacks.

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Understanding Exposure – Aperture, Shutter Speed, and ISO

This photograph of a Great Egret is severely underexposed throwing the background very dark. We see crushed blacks in several

parts of the photograph. The histogram shows the clipped blacks indicating an underexposed photograph

Overexposure

If the amount of light passing through the lens opening for duration of time when the camera sensor is open is more than optimal, then it is called overexposure.

The overexposed photograph will look brighter than the real scene.

Overexposed photographs usually lack details in the highlight regions resulting in the washed out details. The histogram of such photographs, show the distribution towards the right most side with some clipped whites.

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Understanding Exposure – Aperture, Shutter Speed, and ISO

This photograph of a Chipmunk is overexposed as well as underexposed portions. Upper right half of the background is completely

overexposed showing no details. Histogram shows the clipped highlights in the right hand side of the graph

Optimal Exposure

If the photograph looks closer to reality, then the exposure is optimal. As photographers we may decide to either expose and develop the photograph to depict the reality or to depict our artistic vision.

The Belted Kingfisher photograph has the optimum exposure. This is also indicated with the nice distribution of the histogram

without any on either end

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Understanding Exposure – Aperture, Shutter Speed, and ISO

Exposure Range or

Every camera possesses an exposure range or dynamic range that depicts its capability to collect the light information. This light information is later converted to a suitable form to represent a photograph.

In simple terms, an exposure or dynamic range is nothing but the lowest and the highest exposure a camera can record in a given scene. Or the darkest and the brightest details a camera can record in a given scene.

Dynamic range may vary from camera to camera based on how much light the sensor can hold. The larger the sensor and its size, greater the dynamic range, since it can capture higher amount of light.

For example, consider a camera that has 5-stops dynamic range. Suppose, the main subject needs an aperture of f/11 (with constant shutter speed of 1/125th of a ), then everything in the scene that requires an aperture of f/5.6 to f/22 will be represented properly.

Anything below f/5.6 will result in pure black and anything above f/22 will result in pure white.

Note: The Shutter Speed and ISO are assumed to be constant

Let us understand the dynamic range using Shutter Speed instead. Suppose, the main subject needs a shutter speed of 1/125th of a second (with constant aperture say f/11), then everything in the scene that requires a shutter speed of 1/30th to 1/500th of a second will be represented properly. http://www.naturephotographysimplified.com Page 7

Understanding Exposure – Aperture, Shutter Speed, and ISO

Anything below 1/30th of a second will result in pure black and anything above 1/500th of a second will result in pure white.

Note: The Aperture and ISO are assumed to be constant

I have considered a 2-stop lower and 2-stop higher than the normal for the sake of explanation. In reality, the (or negatives) usually tend to preserve more details in the brighter regions than the darker regions. The digital cameras tend to preserve more details in the darker regions than the brighter regions.

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Understanding Exposure – Aperture, Shutter Speed, and ISO

How to achieve optimum Exposure for different scenes

Let us examine how we can find the optimum exposure for various scenarios that we encounter on day to day basis.

How to Achieve Optimum Exposure for a High-key Scene

A high-key scene contains lower dynamic range than a good consumer/pro camera can handle. There will be a uniform distribution of light in the high-key scene. Foggy, rainy and cloudy days usually lead to high-key scene since most of the scene will be equally lit.

High-key scene usually contains the uniform lighting, yielding to lower Dynamic Range

Consider our 5-stop dynamic range camera for example. Assume that we are photographing a waterfall on a cloudy day. It is a well distributed light and mostly the scene is having two dominant , white and green.

If you meter the waterfalls, then the metering may indicate an f/11 as in our example study. So, we have a dynamic range of f/5.6 to f/22.

But as you know, waterfall is the brightest element in the entire scene. There is no subject/object at f/16 and f/22. However, we would have lot of details in the green area or the surroundings. If the shadow regions need a smaller aperture than f/5.6, you will have those region turn to black.

If you happen to expose the scene with f/11 aperture, then you would end up with a darker or an underexposed image.

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Understanding Exposure – Aperture, Shutter Speed, and ISO

This is the time, when you have to make a decision as a photographer to utilize the opportunity to come up with an optimum exposure.

Misty morning scene in Blue Ridge Parkway yields to a high key lighting. The histogram shows that the dynamic range of the

entire scene is limited and can be captured easily.

Note that I have exposed the scene to the right of the histogram

If you decide to expose the waterfalls at f/5.6 by using of +2, then you will get a 4-stop dynamic range (f/2.8 to f/8) to represent the shadow region or the surrounding. This technique is also called as ETTR (Expose To The Right).

In this process, we are opening up the aperture by 2 stops and allowing more light to pass through the lens.

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Understanding Exposure – Aperture, Shutter Speed, and ISO

This way you will have a virtually greater dynamic range to represent the entire region in a much more pleasing way leading to an optimum exposure.

Just by adjusting the levels and slightly increasing the contrast and the color, you can get pleasing results.

Note that the histogram of the developed photograph is well distributed

How to Achieve Optimum Exposure for a Low-key Scene

A low-key scene is exactly opposite to a high-key scene. It has a very high dynamic range than a consumer/pro camera can handle. Mid-day sun yields a low-key scene with lot of highlights and dark shadows creating a very high dynamic range that most of the cameras may not be able to handle.

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Understanding Exposure – Aperture, Shutter Speed, and ISO

Low-key scene usually contains the harsh lighting creating deeper shadows yielding to a higher Dynamic Range Note that low-key scene is not same as HDR (High Dynamic Range) scene. Usually the HDR scene will usually have various levels anywhere from pure black to mid- tones to pure white.

The low-key scene will have shades of blacks and whites at either extremes but rarely have the mid-tones.

Consider our 5-stop dynamic range camera for example. Assume that we are photographing the same waterfall on a sunny day at noon. The light is harsh and casting the shadows at various regions in the surrounding.

If you meter the waterfalls, then the metering may indicate an f/32 and for the surrounding shadow region could require as high an aperture as f/4. It requires at least 7-stop dynamic range to represent both the waterfalls and surrounding regions with details.

Note that, though the scene has higher dynamic range, there is not much to represent in the mid-tones. We have our main subject, waterfalls, at f/32 and the surrounding may be between f/4 to f/8 but nothing in-between f/8 to f/22.

In such cases, we could consider exposing separately for highlights (waterfalls) and shadow regions (surroundings) so that we can later blend these two exposures in Post- Processing software like Adobe Photoshop.

Note that, sometimes overexposing or underexposing a scene is desirable.

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Understanding Exposure – Aperture, Shutter Speed, and ISO

In this photograph, I have intentionally underexposed the background quite a bit to emphasize the yellow color of the flower. The

concept was to show the life amidst sadness or darkness

Sunset and Sunrise times naturally lead to low-key scenes since Sun is always tens of hundreds of time brighter than anything else in the scene.

In case of photographing Sunset or Sunrise, we may have to overexpose the sun to show how powerful the sunlight is.

Whereas, in case of before sunrise or after sunset, we may want to underexpose the surrounding objects to get the silhouette effect to emphasize more on bright and vibrant colors in the sky.

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Understanding Exposure – Aperture, Shutter Speed, and ISO

In this photograph of Sunrise at Lake Superior, I have underexposed the foreground and the middle ground to get the silhouette

effect. This effect emphasizes the color in the sky

How to Achieve Optimum Exposure for Normal Scenes

Generally, most scenes have the dynamic range that can be covered using the exposure range of the camera.

As described in the Camera Metering Modes article, the camera metering sensor(s) are calibrated to calculate the proper exposure for normal subjects of an average . In most of the normal scenes, the metering sensor should be able to give an indication of the optimum exposure.

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Understanding Exposure – Aperture, Shutter Speed, and ISO

By exposing the Bald Eagle scene to the right, I have plenty of details in its feathers. The histogram shows a proper distribution

However, at times, we may opt to slightly underexpose or overexpose a photograph to achieve desired results.

It is almost always good to Expose To The Right (ETTR) of the histogram to retain the greater details in the shadow regions.

In some cases, when the scene contains a mid-toned main subject and a bright background like sky, we might have to underexpose a bit to avoid blowing out the background.

How to Achieve Optimum Exposure for HDR Scenes

Some scenes will have High Dynamic Range (HDR) than what a camera can handle. This is usually true in case of vast with various objects that have different luminous intensities and color.

In such cases, we have to take multiple exposures and later combine these exposures into a single exposure that has higher dynamic range.

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Understanding Exposure – Aperture, Shutter Speed, and ISO

Each exposure should be made by following the same principle that we follow in case of normal scenes.

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The Autumn colors, water and the clouds had a very high dynamic range. I could not fit the entire scene in one photograph. I took

three photographs with one for foreground, one for background and middle tones.

The histograms give a clear view of the exposure of each photograph. I have achieved the high dynamic range by combining the

photographs to form one photograph.

Note that there is range of intensities from dark tones to mid tones to brighter tones

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Effects of filters on Exposure Let us understand how to achieve optimum exposure using filters in some of the tricky situations.

Using Filters to Achieve Optimum Exposure

Despite the fact that some cameras have greater dynamic range and also there are tools to achieve High Dynamic Range (HDR), there is still a need for filters.

Filters usually manipulate the light in one way or the other based on their characteristics. Let us have a brief look at essential filters that we can use to achieve optimum exposure in the field.

Circular Polarizer (CPL) Filter

Circular Polarizer filter is one of the most important filters for the photographers. A CPL filter is mainly used in to:

 Cut any reflections from the surfaces like glass, water, windows, etc  Darken the skies

When we photograph a reflective surface like glass, water, etc, the camera metering might go wrong indicating a wrong exposure. Since camera metering sensors uses the light meters, as we discussed in the Camera Metering Modes, it tends to give wrong exposure. This is especially true if the reflective surface takes up a large space in the frame.

Another important reason for using CPL filter is to darken the skies or saturating the colors, in general, by cutting the reflections from the subjects.

Since Circular Polarizing filter cuts the reflection, the meter reading is more close to optimum. However, in the process of polarization, the filter cuts some incoming light that enters the lens.

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One should account for this loss of light by compensating for the exposure. For instance, if the CPL filter you are using, loses 1-stop, then you have to compensate for the exposure by adding 1 stop exposure to the meter reading.

Neutral Density (ND) Filter

A Neutral Density filter cuts down the light by the designated number of f-stops without manipulating the color.

A ND filter is named based on how many f-stops of light does it block. Examples of some ND filters:

 ND2 filter – Blocks 1-stop of light or lets through only half of the actual light for a given aperture setting  ND4 filter – Blocks 2-stops of light or lets through only 1/4th of the actual light for a given aperture setting  ND8 filter – Blocks 3-stops of light or lets through only 1/8th of the actual light for a given aperture setting

For instance, if the aperture setting needed for an exposure is f/8 and you have added a ND4 filter to the front of the lens, then it will block the light by 2-stops making the effective aperture equals to f/16.

ND filters are very useful when long-exposure is necessary like waterfalls, night scenes and seascapes. If we want to achieve the long-exposure with a required aperture value and slower shutter speed, sometimes it is necessary to cut down the incoming light by several stops.

For instance you are shooting a seascape and you want to use a smaller aperture opening like f/16. The meter reading might show you to use a shutter speed of 1/15th of a second. However, you are interested in a slow shutter speed of 1 sec to smooth out all the waves in the water.

There is a 4-stop difference from 1/15th of a second to 1 sec (1/8 s, ¼ s, ½ s, 1 s).

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If you just use the manual mode and try to bring the shutter speed to 1 sec, then the overall image will be washed out since you are exposing the sensor 4-stops more than the meter reading.

Instead, you would need a ND8 filter to achieve a shutter speed of 1 sec leading to an optimum exposure that you are aiming for.

Graduated Neutral Density (GND) Filters

Graduated Neutral Density filter is a ND filter which only blocks the light from a portion of the scene.

If one part of the scene is extremely bright compared to the rest of the scene, then GND filter is useful to block light only from the extreme bright portion thereby reducing the dynamic range of the entire scene.

For instance, a photograph of a Sunrise or a Sunset scene would usually have the upper portion of the landscape extremely brighter than the foreground and the middle ground. By using GND filters you could block the sunlight coming from the upper portion but allow the light from the rest of the scene.

If the upper portion (like Sunrise or Sunset) needs an exposure of f/32 and the rest of the scene needs an exposure of f/2.8 to f/5.6, then by adding a GND8 (3-stop reduction) you can get an overall dynamic range of f/2.8 to f/11.

In a way, you would have to compensate for the exposure manually by adding the required GND filter to reduce the dynamic range and then expose the scene accordingly.

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Understanding Exposure – Aperture, Shutter Speed, and ISO

Exposure Triangle

Before we get into the core concepts of the exposure in detail, let us go through a very simple and easy-to-understand example.

Once you thoroughly understand the core principle behind the exposure widely known as Exposure Triangle, you will never get confused!

Exposure Triangle

Exposure is a combination of 3 important elements, namely Aperture, Shutter Speed, and ISO. This is usually represented in a form of a Triangle like this:

It can also be represented with a simple equation like this:

If we look at the Exposure Triangle or the simple equation, we understand that any change made to the Aperture, Shutter Speed or ISO results in change in Exposure. Aperture, Shutter Speed and ISO have the predefined standard values that are used by all the manufacturers.

Before getting into the details of the standard values for Aperture, Shutter Speed and ISO, let us consider a hypothetical example. http://www.naturephotographysimplified.com Page 21

Understanding Exposure – Aperture, Shutter Speed, and ISO

For instance, assume that the set of values for:

 Aperture is denoted as: A1, A2, A4, A8, A16  Shutter Speed is denoted as: S1, S2, S4, S8, S16  ISO is denoted as: I1, I2, I4, I8, I16

Note that the values 1, 2, 4, 8, and 16 are powers of 2. Each value is half the previous value and double the next value. So, A4 is half the A2 and twice the A8, S8 is half the S4 and twice the S16 and so on.

Understanding the doubling and halving of light is the most important aspect in understanding Exposure.

We understand a photograph is made when the Camera Sensor is exposed to the light for certain duration.

For , let us quantify the values of Aperture, Shutter Speed and ISO using amount of light they allow:

 A1, S1, and I1 allows the complete light to pass through  A2, S2, and I2 allows half the light to pass through  A4, S4, and I4 allows quarter (1/4th) the light to pass through  A8, S8, and I8 allows 1/8th the light to pass through  A16, S16, and I16 allows 1/16th the light to pass through

Let us take it one step further to see how they add up to give us a single exposure. For a given scene, the optimum exposure needs a proper Aperture value, Shutter Speed value and ISO number like this:

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Understanding Exposure – Aperture, Shutter Speed, and ISO

[Note that the actual settings for Aperture, Shutter Speed and ISO are driven by many factors like Camera meter reading, image aesthetics, composition, light, etc.]

If we happen to change any of the above values, the Optimum Exposure will change accordingly.

For instance, if we decide to change the Aperture from A2 to A4 (to increase the ) it will effectively reduce the light by half there by underexposing the scene.

To get back the optimum exposure, we could either reduce the Shutter Speed value from S8 to S4 or the ISO value from I4 to I2. The resulting equation by changing the Shutter Speed value would be:

Note: We compensated for the loss of light due to Aperture change (A2 to A4) by changing the Shutter Speed value from S8 to S4, thereby balancing the equation The resulting equation by changing the ISO value would be:

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Understanding Exposure – Aperture, Shutter Speed, and ISO

Note: We compensated for the loss of light due to Aperture change (A2 to A4) by changing the ISO value from I4 to I2, thereby balancing the equation The above example can be extended for different values of Aperture, Shutter Speed and ISO.

The idea behind the Exposure Triangle is that exposure depends on the three key factors Aperture, Shutter Speed and ISO in a way that a change in one value results in the change in overall exposure.

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Understanding Exposure – Aperture, Shutter Speed, and ISO

Aperture

Let us now dive deep into understanding the most important aspect of Photographic Exposure, the Aperture.

Aperture

Aperture is the opening in the lens that controls the amount of light that falls onto the sensor to make an exposure.

The opening in the lens can be controlled using the standard set of values for the Aperture. We looked at the hypothetical example in Exposure Triangle article and understood the following key concept: Each Aperture value is half the previous value and double the next value.

Below figure illustrates the concept.

F-stop

Aperture is represented in f-stops, where f stands for . It is theratio of the len’s focal length (f) to the diameter of the entrance pupil of the lens.

N (Aperture) = f (focal length of the lens) / D (Diameter of the entrance pupil)

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This entrance pupil or the window opening can be controlled by using an adjustable diaphragm in the lens, thereby controlling the exposure.

For instance, a 300mm with an entrance pupil diameter of 75mm will have an aperture value of f/4. We can rephrase this sentence like this: A 300mm f/4 lens will have a maximum entrance pupil diameter of 75mm.

300mm (f) /75mm (D) = 4 Or 300mm (f) / 4 = 75mm (D)

An aperture stop or an f-stop is usually denoted as f/aperture value [we will deal with denominator values in a little while]. If we look at the above equation, an increase in the denominator value leads to decrease in the entrance pupil diameter.

300mm (f) / 5.6 = 54mm (D) 300mm (f) / 8 = 38mm (D) In summary:

 Bigger denominator values decreases the diameter of the entrance pupil resulting in less light to fall onto the Camera sensor  Smaller denominator values increases the diameter of the entrance pupil resulting in more light to fall onto the Camera sensor

Let us look at a pictorial representation of the same (Note the relative sizes of the circles).

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An f-stop functions similar to that of a car door. You might have observed that the car door opens in steps. It opens up to some predetermined point and then stops. If you open it further, it opens free up to next predetermined point and then stops again, and so on.

F-stop works very similar to this concept by dictating how much a lens should be open or closed before it stops at a predetermined point. These predetermined points are standardized set of values that every manufacturer follows.

Why do you need f-stops?

Simple reason is to have control over the exposure. It enables you to precisely control how much light should enter the sensor to make a proper exposure. Since every scene requires a different exposure, it is necessary to have different f-stops in order to control the incoming light.

Here are the standard f-stops: f/1, f/1.4, f/2, f/2.8, f/4, f5.6, f/8, f/11, f/16, f/22, f/32, etc Each of these denominator numbers like 1, 1.4, 2, 2.8 and so on are the rounded values of the geometric sequence of √2. http://www.naturephotographysimplified.com Page 27

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For instance, (√2)0 = 1 (√2)1 = 1.4 (√2)2 = 2 (√2)3 = 2.8 …

These are called full stops, which lets-in:  double the light compared to its next stop (bigger denominator number), and  half the light compared to its previous stop (smaller denominator number)

For example:  f/8 allows double the light than f/11 and half the light than f/5.6  f/5.6 allows double the light than f/8 and half the light than f/4

Below picture, which is similar to the one used in Exposure Triangle article, illustrates the concept. Note that the size of the circle (or diameter) decreases as the denominator value becomes larger.

Note that smaller the f-number bigger the size of the entrance pupil and vice versa.

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Fractional F-stops

Manufacturers also give fractional f-stops to have precise control over the exposure. The intermediate stops are usually in steps of ⅓ stops.

Here are the standard fractional f-stops in steps of ⅓ stops: f/1, f/1.1, f/1.2, f/1.4, f/1.6, f/1.8, f/2, f/2.2, f/2.5, f/2.8, f/3.2, f/3.5, f/4, f/4.5, f/5.0, f/5.6, f/6.3, f/7.1, f/8, f/9, f/10, f/11, f/13, f/14, f/16, f/18, f/20, f/22

For instance, consider the intermediate stops between f/5.6 and f/8 which aref/6.3 and f/7.1. http://www.naturephotographysimplified.com Page 29

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 f/6.3 is 1/3rd stop smaller than f/5.6 and 2/3rd stop bigger than f/8  f/7.1 is 2/3rd stop smaller than f/5.6 and 1/3rd stop bigger than f/8

F-Stop notation

Reading an f-stop can be confusing for many. Let us understand the notation in a simpler manner.

 Bigger the f-number smaller will be the diameter of the entrance pupil resulting in lesser light to pass through (f/8, f/11, f/22 are usually considered as smaller )  Smaller the f-number larger will be the diameter of the entrance pupil resulting in more light to pass through (f/2.8, f/4, f/5.6 are usually considered as larger apertures)

In case of any confusion, just take the focal length of the lens you are using and divide it by the standard f-stop denominators like 2.8, 4, 5.6, etc. The resulting value will indicate the diameter of the entrance pupil.

If you remember the below diagram you will never be confused again!

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Depth-of-Field (DOF)

Let us understand how we can use the Aperture settings to achieve required Depth of Field (DOF) in an image.

Depth of Field (DOF)

Depth of Field refers to nearest to the farthest object that is acceptably sharp in an image.

As we understand that image is a 2-dimensional representation of a 3-dimensional medium (width, height and depth).

Just take a look at the scene right in front of you. You can see the objects in their 3- dimensional format. Isn’t it? You can see from few inches in front of you to the farthest object which might be few feet or meters away.

How much can you see from immediate foreground to the background sharply? If you see everything sharply, then your eye has Deep Depth of Field. Which means everything from foreground to background is in clear focus.

Try this now. Bring your thumb as close as possible to your eyes. Concentrate on thumb only, now what do you see?

Do you see only thumb in clear focus and rest blurred? If so, then your eye has Shallow Depth of Field. This means, only one object is in clear focus and rest of the scene falls out of focus.

Let us examine how we can achieve the shallow or deep DOF in photography.

Factors Affecting Depth of Field

There are several factors that affect how much DOF one can achieve. They are:  Aperture (f-stop) http://www.naturephotographysimplified.com Page 32

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 Camera-to-Subject distance  Subject-to-Background distance  Len’s Focal Length  Sensor Size (Full-size or Cropped sensor)  Criterion

For now, let us consider only the Aperture and its effect on Depth of Field. We will consider all other factors along with Aperture to illustrate how they affect Depth of Field in a dedicated article.

Shallow Depth of Field (DOF)

An image is said to have shallow DOF when only a small portion of the image (generally main subject of interest) is in sharp focus, but rest of the scene is out of focus.

Shallow DOF yields to aesthetically pleasing images due to the effect produced by out-of-focus areas. It is extensively used in Macro, Portrait and Photography especially in Bird photography.

Shallow DOF can be achieved with larger aperture values (smaller denominator values) like f/2.8, f/4, f/5.6, etc. It’s that simple! Provided all other factors are taken care of. But there are some exceptions, which you can see in the below photographs! Below are some photographs where I have used Shallow Depth of Field.

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An example of Shallow Depth of Field, where the main subject of interest (Dove) is in sharp focus and the rest of the scene is

blurred.

Aperture setting: f/4

Another example of use of Shallow Depth of Field to make the subject (sparrow) stand out in the frame. The bokeh effect of the

background makes the photograph aesthetically pleasing.

Aperture Setting: f/4

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Another example of use of Shallow Depth of Field combined with back lighting makes this bud glow.

I have chosen the Aperture setting of f/9 to get end to end sharpness in the bud while throwing everything else out of focus!

This was possible due to the fact that I was using a full frame sensor with 400mm lens and was only few feet away from the

subject.

Aperture Setting: f/9

In this photograph, the Cedar Waxwing and the branch it is perching on, are in perfect focus and the rest of the scene is out of

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More depth of field might have brought the background branches in focus which could have potentially ruined this image. Aperture Setting: f/2.8

This is a very different example of usage of Shallow Depth of Field in the Landscape photography.

A normal tendency for this kind of scene is to consider deep DOF. However, I decided to go for shallow DOF bringing only one

kind of Tulips in focus and rest of the Tulips slightly out of focus.

Aperture Setting: f/8

Deep Depth of Field (DOF)

An image is said to have deep DOF when the image is in sharp focus from foreground to background.

Deep DOF is much widely used in Landscape Photography where it is usually necessary to show the entire landscape in sharp focus. However, sometimes keeping only portion of the landscape image in sharp focus yields wonderful image (Tulip garden image).

Deep DOF can be achieved with smaller aperture values (bigger denominator values) like f/9, f/11, f/16, f/22, etc. Here again, we need to take care of all other factors. But there are some exceptions, which you can see in the below photographs!

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A natural scene that demands for a deep DOF. The road that serves as the leading line in the photograph runs from foreground to

the distant background. It is necessary to keep everything in focus.

Aperture Setting: f/9

Note that I am using a middle aperture value f/9 as opposed to general belief of using a very small aperture. But there is

something called hyper-focal distance and also diffraction to consider!

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Yet another example of use of deep DOF in landscape photography. The wooden bridge serves as the leading line to give this

photograph the much needed depth.

Aperture Setting: f/9

As said in the previous example I have considered the hyper-focal distance.

Crabtree falls photograph uses the deep DOF for obvious reasons. The waterfalls which acts as the main subject of interest as well

as the leading line needs to be in sharp focus throughout.

Aperture Setting: f/22

The choice of a very small aperture value was needed to give a silky smooth effect to the waterfalls.

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Simple Experiment to see the effect of Aperture

Try out this simple experiment to see the effect of Aperture on Depth of Field.

1. Setup the Camera on or a sturdy surface. 2. Place the main subject of interest like a flower, vase, or a toy at around 5 to 8 feet from the Camera. 3. Make sure there is atleast 10 feet distance between the main subject and the background. 4. Compose the scene as you wish. 5. Dial the aperture down to the largest f-stop (like f/2.8, f/4, f/5.6). 6. Focus on the main subject. 7. Now take photographs with different aperture settings (f-stops) starting from the largest aperture to the smallest aperture.

If you take a look at the photographs you will see the Depth of Field increases as you go from larger aperture values (small f-numbers like f/2.8, f/4) to smaller aperture values (big f-numbers f/16, f/22). But there are some exceptions, which you can see in the below photographs!

To make this experiment more interesting, you can place a foreground object and a background object. In this way, you could see how foreground object and background objects come to focus as you choose smaller aperture values.

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Shutter Speed

Let us now dive deep into understanding another most important aspect of Photographic Exposure, Shutter Speed.

Shutter Speed

Shutter speed indicates the duration of time the shutter is open to allow light to fall onto the Camera sensor.

While Aperture dictates the amount of light that falls onto the sensor, Shutter speed dictates the duration.

Shutter speed is depicted in or fraction of a second. There are standard values defined for the Shutter speed like: 30 sec, 15, 8, 4, 2, 1, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000, 1/2000, 1/4000, 1/8000

These Shutter speed values work very similar to that of standard Aperture values. Each Shutter speed value allows the light for a duration that is:  double the next Shutter speed value, and  half the previous Shutter speed value

For example, Shutter speed value of 1/15th of a second, allows the light for a duration that is:  double that of 1/30th of a second, and  half that of 1/8th of a second

This doubling and halving mechanism of Shutter speed and Aperture values help you in achieving the desired exposure based on artistic needs.

For instance, you may need to achieve a Shallow DOF (Depth of Field) while photographing your beloved ones. Consider that the Camera meter indicates that you should be using an Aperture of f/11 and Shutter speed of 1/250th of a second.

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You could set the aperture value to f/4 (to achieve Shallow DOF) and increase the Shutter speed (which means decrease the duration of the shutter) to 1/2000th of a second to achieve the same Exposure.

Below table gives you an idea:

Aperture Shutter Exposure Speed

f/11 1/250 Needed Exposure to expose our example scene properly

f/8 1/500 Results in same exposure as above

f/5.6 1/1000 Results in same exposure as above

f/4 1/2000 Results in same exposure as above

All 4 combinations result in the same Exposure for the example scene that we considered. Based on your need, you could either change the Aperture value or the Shutter speed value or both to achieve the required exposure.

Usually you decide on the Shutter speed based on three major needs:

1. To Avoid Camera Shake 2. To Freeze the Action 3. To Achieve Motion Blur

How to Avoid Camera Shake

General rule of thumb to avoid any Camera shake is to choose a Shutter speed that satisfies the following condition:

Min. Shutter Speed to Avoid Camera Shake = 1 / Effective Focal Length

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Understanding Exposure – Aperture, Shutter Speed, and ISO

Effective Focal Length is calculated based on the Sensor size.

 For a Full-Frame Sensor, effective focal length is same as the focal length since there is no cropping. Effective Focal Length = Focal Length of the Lens

 For a Cropped sensor, effective focal length is times the focal length. Effective Focal Length = Crop factor of the Sensor * Focal Length of the Lens

For example, if you are using a 400mm lens on a Full-Frame Sensor (like or Canon 1DX), you need a Shutter speed of atleast 1/500 (closest Shutter speed value of 1/400) to avoid any possible Camera shake.

If you are using a 400mm lens on a Cropped sensor, say 1.5X size, then you need a Shutter speed of atleast 1/1000 (closest Shutter speed value of 1/(400*1.5)) to avoid any possible Camera shake.

However, (IS)/ Vibration Reduction (VR) technology can help to reduce these numbers considerably.

If you have IS/VR that gives 2-stops stabilization, then for the same focal length, you could choose a Shutter speed that is 2-stops lower than 1 / Effective Focal Length. For example, for a Full-Frame Sensor with 400mm lens, you could go with Shutter speed of 1/125 instead of 1/500.

Another option is to use the Tripod. Tripod is very useful in Landscape photography where we need long exposures.

However, for action photography it may be limiting to use the Tripod. Though, it is possible to use Gitzo tripods with Wimberly heads, it may turn out to be expensive.

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How to Freeze the Action

One of the most important aspects of Wildlife/Bird/ is to freeze the action. Freezing the action depends on the speed at which the action happens. There is no ideal Shutter speed that suits for all purpose. In general, the Shutter speed should be faster than the actual speed of the subject in order to freeze the action.

Photographing Barn Swallow in flight was one of the toughest task for me. They are so small and erratic in their flight. By using

higher Shutter speed of 1/3200th of a second, I was able to freeze the action in a more pleasing way

Shutter speeds of 1/1000, 1/2000, and so on usually helps to freeze the fast moving actions. However, this may lead to underexposure since we are allowing lesser and lesser light to fall onto the Sensor.

Since we know that Shutter speed and Aperture go hand-in-hand we can choose larger Aperture sizes (allowing more light) and shooting in day light, so that we can use higher Shutter speeds without underexposing the scene.

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Shutter speed of 1/1000th of a second helped me to freeze this Ibis frozen in time. Every feather is clearly seen due to frozen action.

The impact would have been less had I used the Motion blur instead.

If the subject is moving slowly, then slower Shutter speeds like 1/125, 1/250, 1/500 may be sufficient to freeze the action. However, as you are aware, you need Shutter speed of (1/effective focal length) to minimize the Camera shake.

In such cases, you can either consider using higher Shutter speeds or make use of VR/IS system to compensate for the Camera shake.

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Though Green Herons are sufficiently swift, I was able to freeze this action with 1/500th of a second

How to Create Motion Blur

Motion blur indicates the movement in time in an otherwise frozen frame. Motion blur can be used either to show the motion or to create some artistic results.

In general, the Shutter speed should be slower than the actual speed of the subject in order to create motion blur.

Shutter speeds between 1/15 sec and 30 seconds usually helps to blur the moving action to produce motion blur. However, choosing very slow shutter speed results in too much of light falling onto the Sensor. This could be compensated either by using smaller Aperture values (f/11 to f/32) or by using Neutral Density (ND) filters.

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I got the silky smooth water effect of Manabezho falls in Upper Peninsula using the Shutter speed of 1/6th of a second. A sturdy

tripod is a must in order get the best possible results.

Motion blur technique is most widely used in Landscape photography especially in the Seascapes, Cloudscapes and Waterfalls. In these scenarios, blurring the motion of the flowing water or the moving clouds could yield to very artistic results.

While going for Shutter speeds less than a second, one should go for very sturdy tripod to avoid any Camera shake.

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I have used Shutter speed of 1/13th of a second to slightly smooth out the waterfalls. I could have used slower shutter speeds to

smooth out the water sufficiently. But since I was using the foreground to create the natural frame, I wanted to avoid any blur

Motion blur is also used in Wildlife/Bird Photography to show the motion in a chase sequence, birds in flight, etc. If done properly, motion blur photographs of wildlife could yield excellent results.

To create motion blur in Wildlife/Bird Photography, one has to considering using the Shutter speeds that are little less than the actual speed at which the bird is flying or the animal is running/chasing.

It takes number of iterations and experience to pull out a very good motion blur photograph of an Animal or a Bird. But it is a challenge that every Photographer should look forward to.

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Only the legs of a running animal or the wings of the bird should be blurred keeping the rest of the body in focus to get excellent results. However, it is possible to show a flock of birds with Motion blur technique to create some artistic results.

This bathing scene of female Mallard Duck is taken with 300mm + 2.0 TC (effective 600mm). Ideally the Shutter speed should be

atleast 1/1000th of a second since I use a Cropped sensor.

However, I have used 1/500th of second since the light was less on that evening. We can see that the body is in perfect focus while

the wings show the motion blur giving a hint of what happened next

Motion blur technique is also widely used in to create with city , street lights, moving vehicles, stars, etc.

How to Create Motion Blur using

Generally, motion blur is created by blurring the subject showing the motion. There is another interesting way to create Motion blur; by panning the Camera!

In this case, we pan the Camera to track the moving subject. This way we can freeze the action but let the background go blur due to Camera panning.

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Camera Shake Vs Motion Blur

Note that Camera shake is not same as Motion Blur. Motion blur happens due to movement by the subject that we are photographing while Camera shake is due to the movement by the Photographer while tripping the Shutter button.

A Small Exercise to understand Shutter Speed

It is very easy to understand the effects of Shutter speed at your home! Just follow these steps.

1. Consider a moving subject that rotates on its axis like Fan, Bicycle wheel, Skate wheel, etc 2. Let the subject run at some predefined speed 3. Place the Camera on Tripod 4. Choose Shutter Priority Mode on your Camera . Shutter Priority allows you to select the required Shutter speed and the rest will be taken care by Camera 5. Start taking photographs with various Shutter speeds ranging from 1 sec to 1/4000th of a second

Take a look at all the photographs that you just took. You can see how the look and feel of the subject changes with Shutter speed. Try this experiment with some real subjects like Waterfalls, Birds in flight, Pets running, etc

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ISO

Let us now dive deep into understanding another most important aspect of Photographic Exposure, ISO.

What is ISO?

ISO stands for International Organization of Standardization. In photographic terms, ISO represents the sensitivity of Camera Sensor to the light.

 Less sensitive the Sensor is to the light, more time it takes to expose for a scene, resulting in fine quality photographs

 More sensitive the Sensor is to the light, lesser time it takes to expose for a scene, resulting in lower quality (noisier) photographs

Standard ISO Values

There are standard set of ISO values, similar to that of Aperture and Shutter Speed, to measure the sensitivity of a Sensor. Usual set of ISO values that are found in most Cameras are: 100, 200, 400, 800, 1600, 3200, 6400

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However, there are some Camera variants that support a lower ISO 50 and higher ISO values from 12800 up to 409600.

Note that the numbers are geometric progression of power-of-2.

ISO values work very similar to that of standard Aperture and Shutter Speed values. Each ISO value:

 Doubles the sensitivity of the Sensor compared to its previous value, and  Halves the sensitivity of the Sensor compared to its next value

For example, ISO 200

 Doubles the sensitivity of the Sensor compared to ISO 100, and  Halves the sensitivity of the Sensor compared to ISO 400

By increasing or decreasing the ISO value, we can control the amount of light that is needed to make a proper exposure.

This doubling and halving mechanism of Aperture, Shutter speed, and ISO values help you in achieving the desired exposure based on artistic needs.

Intermediate ISO Values

Every manufacturer gives intermediate ISO values/steps that will help to fine tune the sensitivity of the Sensor.

Complete set of ISO values including the intermediate values is:

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100, 125, 160, 200, 250, 320, 400, 500, 640, 800, 1000, 1250, 1600, 2000, 2500, 3200, 4000, 5000, 6400 Values in red color represent the standard ISO values.

In between two standard ISO values there will be two intermediate ISO values; one for 1/3rd stop and other for 2/3rd stop.

For instance, consider the intermediate stops between ISO 100 and ISO 200 which are ISO 125 and ISO 160.  Sensor at ISO 125 is 1/3rd times more sensitive than ISO 100 and 2/3rdtimes less sensitive than ISO 200  Sensor at ISO 160 is 2/3rd times more sensitive than ISO 100 and 1/3rdtimes less sensitive than ISO 200

The intermediate steps are very important as we can fine tune the ISO sensitivity in order to reduce the noise with higher ISO values.

Effects of ISO values on

Every Sensor has the base ISO at which it will produce the highest quality image (higher Signal-to-Noise Ratio). Base ISO generally is ISO 100 but some models will have ISO 200 as their base ISO.

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I have used ISO 100 for this photograph of a Barn Swallow. You can see from the 100% crop of the head in the below photograph

and it is clean. This can be seen especially in the plain background

100% crop of the head of the Barn Swallow

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As we increase the ISO from its base value, the quality starts to degrade since we are increasing the sensitivity of the Sensor to the light.

Let us consider a simple example to see how the quality degrades with increased ISO values.

Consider that you are photographing an object on a table in your living room at night. You have the constant source of light which is either Tube light or CFL. There is no ambient light present, which means the light does not change.

Now, when you meter the scene using a reflective or your Camera’s metering sensor, you will get the metering for the proper exposure. Say for instance, you are using a 50mm f/1.8 lens and the metering says you need to use an Aperture of f/1.8 and Shutter Speed of 1/15th of a second.

You know that Shutter speed of 1/15th of a second will make the image blurred since you know that you need a Shutter speed of atleast 1/60th of a second (assuming full frame camera) to get a sharp image. There is a gap of 2-stops between 1/15th and 1/60th of a second. One way is to decrease the Aperture by 2-stops to allow more light. But we are already at the maximum Aperture. Or you can use Tripod. Let us assume you do not have one.

Now, the only option is to change the ISO from ISO 100 to ISO 400 so that you can use a Shutter Speed of 1/60th of a second.

What happens when you increase the ISO?

In our example, the light is same, scene has not changed, Aperture opening is same and Shutter Speed is decreased to allow less light! Then where is extra light coming from?

In reality there is no extra light here. Only the Sensor is tuned to become more sensitive to the light by virtually shifting the incoming signal level (or boosting the signal) by a certain factor.

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When the signal levels are shifted (could be multiplied by a factor), the noise level also gets shifted resulting in lower Signal-to-Noise Ratio (SNR), which in turn result in poor image quality.

This photograph of a Male Mallard Duck taken at ISO 320 looks so clean at the full resolution. However, below image of 100%

crop on its beak shows the noise in the clean background

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100% crop of the beak of Mallard Duck

Loosely speaking, this could be related to Optical Zoom Vs Digital Zoom. Optical zoom uses the actual mechanical components like lens elements to do the zoom. When sensor captures the zoomed image it is always at its highest resolution.

Whereas, in case of Digital Zoom, the sensor captures at its highest resolution with no zoom and later the image is cropped to get the required zoom and re-scaled back to the original resolution. So, there is always a loss of quality in case of Digital Zoom.

Making changes to Aperture and Shutter Speed to achieve the required Exposure can be equated to Optical Zoom, whereas a change to ISO is similar to that of the Digital Zoom.

How far can you push the ISO?

It depends on you and the Camera that you are using.

Today’s DSLRs have amazing ISO capabilities. Most of the manufacturers have found ways to reduce the higher ISO noise within the Camera using proven techniques. In some Cameras you can go as high as ISO 1600 without too much of noise in the image. http://www.naturephotographysimplified.com Page 56

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This photograph of a beautiful flower after a rain shower was taken at ISO 1600!

100% crop on the petal shows the terrible noise especially in the background.

However, since the background is mostly out-of-focus with no details, it was quite easy to remove the noise in the post-processing

to get an usable photograph

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100% crop of the flower petals

The best possible way to know is to shoot at different ISO levels. Basic rule of thumb is to use the lowest ISO possible at all conditions.

Only when the situation demands, you should push the ISO levels up.

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This photograph of a magnificent Bald Eagle diving down was taken at the Sunset with ISO 800. During Sunrise and Sunset

times, we cannot help but use higher ISO numbers since there is not much of a light to capture the action.

Though it looks very neat in full resolution image, 100% crop on the wings show the loss of details in the feather and also the noise

100% crop on the wing of Bald Eagle

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Most important thing is:

 Know your Camera  Know its ISO capabilities  Experiment with one subject and different ISO numbers  Experiment in different lighting conditions

Note that noise usually resides in the lower lit areas or shadows. If you have good enough light, you may not have a bad quality image with higher ISO. But you may get really poor quality image if there are several objects in your scene that are in shadow.

In summary, experiment with different ISO values with different lighting conditions and find out the tolerance limit, both for your Camera and You!

A Word on Post Processing to reduce ISO Noise

Though it is possible to reduce the ISO noise in post, you should remember that reducing the noise makes the image look smooth. Because, a noise reduction filter is a low-pass filter that smoothen out the edges.

This could be a real problem when you want to reduce noise levels on the subject with lot of interesting textures and fine details like in bird’s feathers.

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This photograph shows the resulting photograph after applying Noise Reduction on the Bald Eagle wings. You can see that the

noise is reduced but small textures in the feather is lost and also the features on whole are softened due to low-pass filter effect

Therefore, it is always better to use the lowest possible ISO to avoid any kind of disappointments.

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Summary

Let us wrap up this long series by looking at how to use three pillars of Photographic Exposure – Aperture, Shutter Speed and ISO to achieve the optimum exposure and aesthetically pleasing photographs.

Let us recap the most important aspect of photographic exposure – exposure triangle.

Exposure Triangle

Exposure is a combination of 3 important elements, namely – Aperture, Shutter Speed, and ISO. This is usually represented in a form of a Triangle:

It can also be represented with a simple equation like this:

If we look at the Exposure Triangle or the simple equation, we understand that any changes made to the Aperture, Shutter Speed or ISO results in change in Exposure. Aperture, Shutter Speed and ISO have the predefined standard values that are used by all the manufacturers.

Aperture is represented in f-stops and the standard values are: f/1, f/1.4, f/2, f/2.8, f/4, f5.6, f/8, f/11, f/16, f/22, f/32 … http://www.naturephotographysimplified.com Page 62

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Each Aperture value allows

 Double the light compared to next Aperture value, and  Half the light compared to previous Aperture value

Shutter Speed is depicted in seconds or fraction of a second, and the standard values are: 30 sec, 15, 8, 4, 2, 1, ½, ¼, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500 …

Each Shutter Speed value allows  Double the light compared to next Shutter speed value, and  Half the light compared to previous Shutter speed value

Standard ISO values are: ISO 100, 200, 400, 800, 1600, 3200, 6400, 12800 …

Each ISO value  Doubles the sensitivity of the Sensor compared to its previous value, and  Halves the sensitivity of the Sensor compared to its next value

Understanding the doubling and halving of light is the most important aspect in understanding Exposure. Below diagram summarizes the doubling and halving effect of each of these three parameters.

Effects of Aperture, Shutter Speed, and ISO http://www.naturephotographysimplified.com Page 63

Understanding Exposure – Aperture, Shutter Speed, and ISO

Aperture affects the Depth of Field (DOF) in a photograph. If you want deeper DOF, you will choose smaller Aperture settings like f/11, f/16, f/22, etc. On the other hand, if you need Shallower DOF (or Bokeh) you have to choose larger Aperture settings like f/1.4, f/1.8, f/2.8, etc.

Shutter Speed helps to either freeze the action or blur the action. Freezing or blurring the action depends on the speed at which the action takes place. For instance, you can freeze the current in the water by choosing a shutter speed of 1/25 and above. To freeze the action of bird in flight you may need 1/500 and above.

ISO helps to either choose the required Aperture or the Shutter Speed setting depending on the scene.

Which Aperture, Shutter Speed and ISO Settings is Best for Your Photography?

Well, it depends on the scene!

Let us take a look at different possibilities and the recommended settings that you can choose for your photography needs.

Settings for Landscape Photography

If you need Deep DOF in your landscape photographs, then choose:

 Smaller Apertures like f/11, f/16, f/22 (remember that smallest apertures tend to introduce diffraction and soft effect)  Shutter Speed based on the Aperture setting and the available light  Low ISO like 100, 200  Use Tripod

You must use tripod if you aim to take sharper images.

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I have achieved Deep Depth of Field (DOF) using small Aperture value of f/9, Shutter speed of 1/25, and ISO 100. I have used Tripod to keep get sharper image from foreground till background

If you need Shallow DOF in your landscape photographs (mostly close-ups), then choose:

 Larger Apertures like f/1.4, f/1.8, f/2.8  Shutter Speed based on the Aperture setting and the available light  Low ISO like 100, 200

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Here I have achieved Shallow Depth of Field (DOF) by using Aperture value of f/4, Shutter speed of 1/1000, and ISO 100. Observe that the blade of grass in the bottom is out of focus though it was only few cms from the Dragonfly!

Note: In Landscape Photography, generally the choice of Aperture drives the exposure.

Settings for Wildlife/Bird Photography

To freeze the birds in action, choose:

 Higher Shutter Speeds like 1/500 , 1/1000, etc to avoid any camera shake and/or motion blur  Larger Apertures like f/1.4, f/1.8, f/2.8 to enable faster shutter speeds  Lowest possible ISO to accommodate the required aperture and shutter speed setting

You may use tripod to avoid camera shake or to gain more shutter speed or to cut down the unwanted shadows.

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Understanding Exposure – Aperture, Shutter Speed, and ISO

Freezing the action is the most challenging and rewarding task in action photography. Aperture of f/4 and ISO of 320 helped me to gain on the Shutter speed of 1/1000th of a second to freeze the landing action of this Bald Eagle

In this early morning photograph of a Common Raven perching on a high tension electric wire, I have used a higher Shutter speed of 1/2500th of a second to freeze the action. Since Sun was low in the and was soft, I chose larger Aperture value f/2.8 and higher ISO value of 640 in order to get Shutter speed of 1/2500

To blur the birds in action, choose:

 Slower Shutter Speeds like 1/60 , 1/125, etc to avoid any camera shake but introduce motion blur  Middle Apertures like f/5.6, f/8, etc to enable slower shutter speeds http://www.naturephotographysimplified.com Page 67

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 Lowest possible ISO to accommodate the required aperture and shutter speed setting

You may use tripod with Gimbal head to avoid camera shake while tracking the subject, since the slower shutter speeds generally yield to camera shake.

Settings for Waterfall/Cloudscape/Seascape Photography

Waterfalls, Cloudscapes, and Seascapes generally require Deep DOF clubbed with slower Shutter Speeds. It is a common technique to blur the action in the photograph to create a surrealistic effect.

You can choose the below settings:

 Slower Shutter Speeds, usually less than a Second  Smaller Apertures like f/11, f/16, etc to enable slower shutter speeds and to get deep DOF  Low ISO like 100, 200

Tripod is a must for long exposure photography.

Waterfalls and Seascapes are probably most favorite subjects for Landscape Photographers. They generally look pretty or surrealistic when they are captured with long exposures. In this photograph of Indiana Dunes beach, I have used a slower Shutter speed of 2 second, Aperture value of f/11, and ISO 100. Shutter speeds of 8 or 15 seconds would have cut down all the ripples in the water making it surrealistic

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Conclusion

Understanding photographic exposure requires you to understand all the concepts described in each part. As always you need to practice. Unless you practice, any amount of reading will be waste of time and energy.

Try manipulating the exposure just by changing the Aperture and see how it affects the final result. Repeat the same thing with Shutter Speed and ISO.

Once you are able to change Aperture, Shutter Speed, and ISO independently then it is not tough to change them together to achieve the required exposure.

Make mistakes! Learn by mistakes. Don’t stick to optimum exposure alone. Try intentional underexposure, overexposure, , long exposure, etc. You will be stunned with the resulting images. You will enjoy it for sure.

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http://www.naturephotographysimplified.com Page 69

Understanding Exposure – Aperture, Shutter Speed, and ISO

About the Author

Prathap is the founder of http://www.naturephotographysimplified.com blog. An avid Nature Photographer with much inclination on Landscapes, Birds and Wildlife. He has gained deeper knowledge on Photography Concepts and DSLR Camera techniques from his 6 years of Photography. He believes in simplicity and aims to share his knowledge to empower the Photographic community.

He is the author of very popular eBook “15 Incredible Bird Photography Tips for Beginners”. Subscribers of his blog, gets to download this eBook for FREE!

You can connect with him via

http://www.naturephotographysimplified.com Page 70