Camera “Autofocus” Basics

It’s been awhile since my last post as I have been working on how to simplify a complex subject to explain controlling the camera’s autofocus system by covering the basics of what you need to know to start getting sharp images.

The camera’s focusing system plays the primary role in helping you achieve a sharp image. Depending on the type of camera there are a number of aspects that we need to discuss, to learn how to set the camera focusing system to best match your shooting scenario.

Acquiring focus, with the default settings, will start when you push the shutter button 1/2 way down while pointing at a subject of interest. At this moment, the camera will determine the exposure and focus the lens simultaneously within fractions of a second. However, we need to understand what focus settings are best for each shooting scenario to know how to set them accordingly.

We will discuss the basic settings of the focus system by breaking it down into three parts; (1) Focus mode switch (selecting autofocus or manual), (2) Autofocus mode (choosing a single or continuous autofocus mode), and (3) Focusing area (setting a focus point or focus area), is the most complex part of the focusing system.

(1) Focus mode switch: DSLR’s, with Canon the Focus mode switch is typically located on the barrel of the lens. Set the switch to the “AF” position to enable autofocus. If you set the switch to the “MF” position autofocus is disabled, then you are required to manually adjust the focus by turning the focusing ring on the lens. For most situations, typically set the mode switch to “AF” position.

For Nikon the designations are “M/A”, autofocus with manual override, and “M” for manual.

When using a bridge camera such as a Canon SX30, or a compact camera such as the Canon SX100, access the Focus mode by first pressing the left “◄” of the “control dial“. Then press the left “◄” or right “►” of the “control dial” to select one of the three (3) focus modes; Macro (autofocus for close subjects), Normal (autofocus for non-close subjects), and Manual (manual focus mode).  To accept the setting press the “func/set” button located in the center of the “control dial“.

When using an iPhone with the native camera app you do not have the ability to manually focus, if you want manual focusing capability choose a third party camera app, for example; Camera+, ProCamera or VSCO. Refer to their respective manuals to learn how to switch between the auto or manual focus setting.

(2) Autofocus modes: DSLR’s, with Canon there are typically three autofocus modes to choose from; One Shot, AI-Focus, and AI-Servo. (A) The “One Shot” setting is best used for subjects that are not moving, (B) “AI-Focus” will automatically switch between “One Shot” if the subject is stationary and “AI-Servo if the camera detects the subject is moving, and (C) the “AI-Servo” setting is best used for subjects that are moving.

For Nikon the three autofocus modes to choose from are; (A) “AF-S” (Single-servo autofocus for stationary subjects), (B) “AF-A” (Auto-servo autofocus the camera automatically switches between AF-S if the subject is stationary or AF-C if the camera detects the subject is moving), and (C) “AF-C” (continuous-servo autofocus for moving subjects).

When using a bridge camera such as a Canon SX30, there are two autofocus modes to choose from; (A) Servo AF Off or (B) Servo AF On, accessed by pressing the menu button and then the “▲” or “▼” on the control dial, then use the “◄” or “►” to change the setting. Servo AF Off is used for stationary subjects while Servo AF On is used for moving subjects.

When using a compact camera such as the Canon SX100, there are two autofocus modes to choose from; (A) Single or (B) Continuous, accessed by pressing the menu button and then the “▲” or “▼” on the control dial, then use the “◄” or “►” to change the setting. Single is used for stationary subjects while Continuous is used for moving subjects.

With an iPhone you tap the screen where you want to focus and the camera is in continuous focus mode, if you tap and hold, the AE/FE lock will appear and at that point the camera holds that focus setting.

(3) Focusing Area: DSLR’s, depending on the camera capabilities will vary. With a Canon T6i for example there are three Focus areas to choose from; Single-point AF, Zone AF, and 19-point auto select AF. (A) Single-point AF allows the user to manually select any one of the 19 focus points. (B) Zone AF allows the user to manually select groups of focus points. (C) 19-point auto select AF allows the camera to select the focus point that is closest to the subject. Starting out the recommended setting would be (B) Zone AF as the user has the ability to manually move the groups to an area to satisfy the desired composition.

For a Nikon D5100 for example there are four Focus areas to choose from; Single-point AF, Dynamic-area AF, 3D-tracking, and Auto-area AF. (A) Single-point AF allows the user to manually select any one of the 11 focus points. (B) Dynamic-area AF allows the user to manually select the focus point with the camera using adjacent focus points to help keep the subject in focus. (C) 3D-tracking allows the user to manually select the initial focus point which then allows the camera to track the subject focused on by using all the focus points. (D) Auto-area AF allows the camera select the focus point that is closest to the subject. Starting out the recommended setting would be (C) 3D-tracking.

When using a bridge camera such as a Canon SX30, there are three Focus areas to choose from via the AF Frame menu option; FlexiZone, Center, and Face Detect. (A) FlexiZone is for focusing on a specific point where the user can change the size and position of the frame. (B) Center locks the frame to the center. (C) With Face Detect the camera automatically tries to detect peoples faces, locks on and attempts to follow the subject to keep the subject in focus. Starting out the recommended setting would be (A) FlexiZone.

When using a compact camera such as the Canon SX100, there are two focus areas available via the AF Frame menu option; Center and Face Detect. (A) Center locks the frame to the center. (B) With Face Detect the camera automatically tries to detect peoples faces, locks on and attempts to follow the subject to keep the subject in focus. Starting out the recommended setting would be (A) Center.

With an iPhone the only focus area is the box that appears when you tap the screen. If you do not tap an area on the screen the camera will decide on what it thinks is the focus point. Starting out the recommended operation is to tap the screen where you want the camera to focus.

Take time to go over this lesson concentrating on the sections that best apply to your camera. The focus system is something that will take time to master and with more practice you will eventually be able to understand and control the appropriate settings to achieve sharp images.

The camera “mode” dial

Canon T6i Mode Dial

The camera mode dial provides a means for the user to help the camera make better aperture, shutter speed and ISO setting decisions based on typical scenarios.

The mode settings; M, Av, Tv, P, etc…, are set by turning the dial on your camera to the desired position that best suits the shooting scenario.

The mode dial is typically split into two areas; (1) the creative zone and (2) the basic zone. For this lesson we will discuss the modes within the “creative zone“.

“M” – Manual Mode
The user takes complete control setting the aperture, shutter speed, and ISO for a correct exposure based on the camera’s exposure metering mode, also set by the user. The exposure value is the resulting exposure from the user settings, displayed on the camera’s reflective meter. The camera can auto adjust the ISO if it is set to AUTO. The user can limit the highest ISO value via a setting typically found in the camera menu.

“Av” – (Nikon “A”) Aperture Priority Mode
The user takes control of setting the aperture and ISO. The camera automatically sets the shutter speed for a correct exposure based on the current exposure metering mode setting and the exposure compensation setting, both controlled by the user. Aperture is part of the creative control for depth of field. The camera will also adjust the ISO if it is set to AUTO. The user can limit the highest ISO value via a setting typically found in the camera menu.

“Tv” – (Nikon “S”) Time Value (Shutter Priority) Mode
The user takes control of setting the shutter speed and ISO. The camera automatically sets the aperture for a correct exposure based on the current exposure metering mode setting and the exposure compensation setting, both controlled by the user. Shutter Speed is part of the creative control to show motion. The camera will also adjust the ISO if it is set to AUTO. The user can limit the highest ISO value via a setting typically found in the camera menu.

“P” – Program mode (Does NOT mean Professional Mode)
The camera automatically sets the shutter speed and the aperture value for a correct exposure based on the current exposure metering mode setting and the exposure compensation setting, both controlled by the user.

In “P” mode the camera uses an algorithm based on the amount of available light in addition to the lens aperture and focal length capabilities. The user can adjust the camera’s determined settings by moving the main dial (on the top right front of the camera adjusted with your index finger). While adjusting the main dial you will see both the shutter speed & aperture change, however, once the lens has reached the widest aperture you will not be able to adjust the shutter speed any higher. Note the algorithm starts fresh each time you take a picture.

The camera will also adjust the ISO if it is set to AUTO, the camera tends to use the lowest possible value while still maintaining a minimum of 1/(focal length) shutter speed. The user can limit the highest ISO value via a setting typically found in the camera menu.

In our next lesson we will discuss how a camera performs auto focus and what the settings mean.

What is “White Balance”

Up to this point we have talked mostly about achieving a correct exposure by paying close attention to the intensity of light, but we also need to consider the colour of light and know how to set our camera to capture it correctly by setting a proper “white balance“. The white balance settings available on your camera are basically presets that can be set to match the ambient lighting conditions allowing the captured image to be the proper colour. The colour temperature of light is measured in degrees Kelvin using the symbol “K” which is a standard that provides a means to compare light sources.

Camera’s currently do not have the artificial intelligence to correct for the colour temperature of a scene, this is why we need to understand how to evaluate the lighting conditions and set the camera so it can capture the correct colour. The “white balance” basically ensures that the white in the scene actually looks white.

Typical preset settings are represented by symbols which have specific colour temperatures or ranges of temperatures for general situations.

With “AWB” the camera automatically evaluates the scene trying to interpret an appropriate white point to determine the temperature setting. This method works good for most daylight conditions.

When taking photos in doors it is better to set the white balance using the Tungsten or Fluorescent setting. However, it is important to understand there is a wide range of in door lighting used from a colour temperature perspective, therefore it is best to try a few white balance settings to see which gives the best result. It may be necessary to set a “custom” white balance to ensure proper colour in the captured images. To set a custom white balance it is important to use a calibrated gray card and follow the procedure in your camera manual.

There may be a specific requirement to set a specific temperature, for example, when taking photographs of products. Usually for this situation the colour temperature of the light source is known and you then set the camera to the same Kelvin setting to match.

The setting of the colour temperature is more important when capturing images as “Jpeg” because the colour temperature is directly applied to the image. When capturing images in “RAW” the colour temperature can be changed using post processing but it’s always good to set the right white balance so the image preview on the back of your camera has the correct colour.

Below is an example of the same image with three different colour temperature settings. The image was taken near a window with daylight lighting, center image 5500⁰K, left image 3500⁰K, and right image 7500⁰K. Notice the left image has a blue tint which is a cooler colour, and the right image has an orange tint which is a warmer colour.

When adjusting white balance for a portrait it is important to maintain the proper colour to match the skin tone, therefore matching the camera white balance colour setting to the match the ambient light is important. For a landscape you have a bit more freedom to make the resulting image cooler or warmer based on how you want the viewer to feel which can be used as a creative adjustment.

In our next lesson we will take a look at the camera mode dial and how each setting will help you collaborate with your camera to have a better chance of getting a good exposure when capturing an image under certain situations.

How to understand the “Histogram” and “Highlight Alert”

When looking at a captured image on the back of your camera’s display the perceived brightness is influenced by the brightness setting of the display and the ambient light (the light around us). For example, on a bright sunny day looking at the display on the back of your camera is hard to even see the image verses viewing the display on a cloudy day where you are able to see the image easily. It is therefore not possible to see an accurate representation by just viewing the captured image on the display to determine if it is properly exposed.

Viewing the “histogram” for a captured image is a consistent method of determining if it is properly exposed. The histogram is basically a graph of the number of pixels versus the brightness of those pixels in your image. First we will discuss just the “luminance” part of the graph which represents the image brightness scale at the bottom horizontal part of the graph with 0% brightness (black) on the left through 50% brightness all the way to 100% brightness (white) on the right. The number of pixels in the image with their specific brightness’s are shown on the left side scale vertically throughout the graph starting at 0 on the bottom to the maximum number of pixels at the top.

The most important part of the histogram is the most left black area and the most right white areas which are referred to as the clipping points. The “clipping point” means if you hit the minimum value of 0% brightness it will be pure black, and conversely if you hit the maximum value of 100% brightness it will be pure white. Once you reach the clipping point there will be no detail in that part of the image. For example, the sky on a clear bright day should be light blue, if the captured image is over exposed the sky will be white because the 100% brightness clipping point was reached.

By using the three colours; “red”, “green”, and “blue”, it is possible to create all the colours that you see in the captured image. Similar to “luminance“, which represents the brightness of the image as if it were in only black & white on the histogram you can also see the “RGB histogram” with individual graphs that represent each of the colours; “red“, “green“, and “blue” and their respective brightness.

It is important to understand there is no such thing as a typical or perfect histogram, they will all look different based on the subject matter of the scene you have taken an image of.  Let’s take a look at a sample image to see what the actual histogram on your camera would look like.

Fontaine de Tourny, Quebec, Canada, f/14, 10 sec, ISO 200, @70mm

Luminance Histogram

What you typically see on your camera is the “luminance” histogram. Notice most of the concentration of pixels, for the above fountain image, is on the left side which represents the black and darker areas in the image, as you look toward the right the rest of the pixels represent the brighter parts of the image. Notice that the luminance graph does not go all the way over to the right.

RGB Histogram

With the RGB histogram it breaks down the brightness of each of the “red”, “green” and “blue” colour pixels. It is important to notice that the “red” and “green” histogram pixels show they go all the way over to the right and are not pushed up on the right hand side which is different than what we see with the luminance histogram. This is why it is so important to view both the luninance and RGB histograms, to make sure that the luminance or any of the red, green or blue colours are not clipping. Note, not all cameras provide the capability to see the RGB Histogram.

f/8, 1/2000, ISO 640, @400mm

With the difficulty in determining if the captured image is over exposed, another tool available to help is the “Highlight Alert“, typically enabled via the menu on most cameras. You will see the image displayed blink from white to black and back to white in the areas of the image that are clipping at the white point (the right hand side of the histogram). Once you have reached the highlight clipping point it will be pure white and you will no longer have detail in those areas. In this image the feather detail will be lost in the areas that are blinking.

Now that we have learned the concepts to achieve a good exposure, in our next lesson we will discuss how to get your camera to capture your image with proper colour by controlling the “white balance” settings.

Understanding the “Metering Modes” in your camera

Now that you know your camera measures light and understand that you can influence the camera’s decisions on image brightness using “Exposure Compensation“, there is yet another way to help the camera make better exposure decisions by controlling the “Metering Mode“.

On most cameras there are at least three (3) metering modes; evaluative or matrix, spot, and center. On more advanced cameras there is also a fourth called partial metering mode.

With evaluative or matrix metering mode, the camera evaluates the whole scene equally to determine how to set the aperture, shutter speed, and ISO resulting in an overall exposure (brightness) of the captured image. This mode would typically be used when taking landscape images.

In center metering mode, the camera will base it’s exposure decisions more on the center of the scene rather than the outer part of the of the scene which typically results in a brighter exposure verses using evaluative metering mode. This mode would typically be used when taking a portrait when the subject is slightly backlit.

With partial metering mode, the camera bases the exposure on approximately 10 percent of the center of the scene. This mode is typically used for taking portraits when the subject is directly backlit and the subject is more important than the background of the scene.

Finally spot metering mode allows the camera to determine the exposure based on the small area in the center of the scene. This mode is good for taking images of wildlife where the scene situations can be changing constantly as the subject is moving around. Again this mode is used when the subject is more important than the background.

In our next lesson we will discuss the two most important indicators on your camera that help with ensuring you have achieved a correct exposure; the highlight alert and the histogram.

 

 

What is “Exposure Compensation”

Your camera is a device that takes pictures, but there is a lot going on behind the scenes that the software in your camera takes care of in fractions of a second.

With your camera in an automatic or semi-automatic mode, as you press the shutter button half way down your camera does two operations; 1) focuses on the subject you are pointing at and 2) measures the exposure so the camera can set what it thinks are the correct aperture, shutter speed and ISO settings. Once you finish pressing the shutter button all the way down the camera captures the image. As you review the captured image you may notice that the result may not be quite what you expected, it may be too bright or too dark depending on the decision that the camera made based on the current lighting conditions, main subject, and surrounding area.

The camera software does not yet have the artificial intelligence to always determine the optimum settings to achieve a correct exposure for any given scene. This is where you, have the ability to control the camera to make the next image a bit brighter or darker depending on the “Exposure Compensation” setting.

In automatic, or semi-automatic modes you can force the camera’s light meter to a brighter or darker setting by changing the “Exposure Compensation”. “Exposure Compensation” is also referred to as “Exposure Value” or “EV” for short. The first time you set the EV away from the default setting of “0” and you want the next image to be brighter move the setting toward “+1”, or if you want the next image to be darker move the setting toward “-1”. Each mark on the meter is in 1/3 stop increments in which three movements equals a stop.

This tells the camera that what ever it thinks is the right exposure, you have chosen to make it brighter or darker depending on your EV setting. This is how you work collaboratively with the camera to create a proper exposure even though the camera is in an automatic or semi-automatic mode.

As an example lets see how to change the EV setting on two Cameras:

1. To change the EV setting on a Canon SX30 in aperture priority mode, “Av” (manual pg 73); press the “+/-” or up arrow button, on the back of the camera, until you see +/-0, then turn the “dial”, on the back of the camera, clockwise to make the EV brighter, positive direction, or counter clockwise to make it darker, negative direction.
2. To change the EV setting on a Canon T6i in aperture priority mode, “Av” (manual pg 159); press the “Av+/-” button, on the back of the camera, and then turn the “main dial”, on the top right of the camera, clockwise to make the EV brighter, positive direction, or counter clockwise to make it darker, negative direction.

As an exercise, use your camera to take three pictures of the same subject; image (1) with the EV set to “0”, image (2) with the EV set to “+1”, and image (3) with the EV set to “-1”. You will notice that the 2nd image is brightest, the 1st image is darker than image 2 and the 3rd image is the darkest.

There is an additional “metering mode” control that also helps the camera further understand what type of subject you are trying to take an image of, which will be discussed in our next lesson.

What is the Exposure Triangle

The exposure triangle is an analogy or standard way to explain the result that aperture, shutter speed, and ISO have on exposure. Each setting represents a side of the triangle with the overall size of the triangle representing the exposure (brightness) of the image.

You can think of the triangle as a piece of pie or a slice of pizza, the bigger the slice the brighter the photo. Make the photo brighter or darker by adjusting one or more of the three settings. The setting(s) you choose to change is based on the creative control that we have learned in our past lessons; Creative control with aperture, and “Motion” the creative control behind shutter speed.

If you slow down the shutter speed, toward 1/4, there is a longer duration for the light to be available to the sensor resulting in a brighter exposure and as a result a larger triangle. Conversely, if you speed up the shutter speed, toward 1/1000, there is a shorter duration resulting in a darker exposure.

By increasing the size of the aperture, toward f/2.8, which allows more light into the camera resulting in a brighter exposure. Conversely, decreasing the size, toward f/16, of the aperture reduces the light into the camera resulting in a darker exposure.

Also, increasing, toward 1600 (more noise), the ISO amplifies the image from the sensor resulting in a brighter exposure. Conversely, if we decrease, toward 100 (less noise), the ISO it decreases the amplification resulting in a darker exposure.

Adjusting any of the three settings; aperture, shutter speed, and/or ISO, requires consideration of the creative control that aperture and shutter speed provide as well as considering the quality of our image with ISO at the same time achieving a proper exposure.

In our next lesson we are going to discuss how the camera measures exposure and how you can help the camera control the exposure in auto and semi-automatic modes.

 

What is Exposure

Exposure in simple terms is the brightness of the over all photograph. The exposure can be controlled completely by the camera, auto mode, or completely by the user, manual mode. In semi-automatic modes the user and the camera work collaboratively to determine the final exposure.

“Incident Light” – Light which is directly falling on a subject

“Incident Light” is the light which is directly falling on a subject transmitted from a light source. In this case the diagram shows the light from the sun, transmitted light, falling on, the box object, the photographer, and surrounding area, referred to as incident light. With the photographer in the current position, the camera is not able to measure the incident light falling on the object.

“Reflected Light” – Light which is bouncing off the object and surrounding area

“Reflected light” is the light reflected off the object and the surrounding area which originated from the “incident light”. This light enters the camera and based on the aperture, shutter speed, and ISO settings creating the final exposure when you push the shutter button.

The camera has a built in continuous light meter, seen through the view finder or in live view mode, to help the camera determine what is a good exposure by measuring the “reflected light“. The light meter meter indicator moves, left or right, shown on the meter as it indicates the amount of light the camera sees displaying the result on a scale typically from [ -2 to 0 to +2 ].

So far we have learned aperture, shutter speed, ISO, light, and how the camera measures the light. To put these terms together let’s look at the following teeter-totter/seesaw concept of a balance analogy to help explain the interaction between the aperture, shutter speed and ISO settings.

In “manual mode” as we adjust any of the three settings; aperture, shutter speed, or ISO, away from being balanced (proper exposure) by 1/3 stones, the brightness (exposure) of our image will be either brighter or darker depending on the adjustments made.

In the directly above example, if we set the aperture larger, a bigger hole by removing 1/3 stones, the seesaw will move up toward the too bright point. Conversely, if we set a smaller aperture, a smaller hole by adding 1/3 stones, the seesaw will move down toward the too dark point.

In the next above example, by setting the shutter speed to a longer duration, by removing 1/3 stones, the seesaw will move up toward the too bright point. Conversely, if we set the shutter speed to a shorter duration , by adding 1/3 stones, the seesaw will move down toward the too dark point.

ISO also plays a role in exposure, if we increase the ISO to a higher value it will push the seesaw toward the too bright point. Conversely, if we decrease the ISO to a lower value it will become closer to the too dark point.

From these examples we can see that there is a balance to maintain between aperture, shutter speed and ISO. If we change aperture we also need to change shutter speed in the opposite direction to maintain the balance (proper exposure). If we adjust ISO we also need to change the aperture or shutter speed settings to maintain a proper exposure.

In our next lesson we will introduce the concept of the exposure triangle which is the most common terminology used to discuss exposure.

How “ISO” plays a role in exposure

In film (analog) photography, ISO is referred to as film speed which is actually the sensitivity of the film to light based on a scale created in 1987 by the International Organization for Standardization.

With digital technology the ISO setting on the camera controls the amplification of the image sensor which simulates the sensors sensitivity to light.

Digital sensors set to higher ISO values experience similar limitations as with film, where the noise in the image will increase as the ISO is increased. Digital noise is not as uniform nor as pleasing as film grain, however, software in the camera and in post-processing applications have improved to better control/reduce the digital noise.

f/8, 1/400, ISO 1000, @ 400mm

The digital noise in the resulting photograph depends on a number of factors, the age and type of camera sensor (technology), the processing engine of your camera, the ISO setting and the exposure. Notice with the image of the duck even though taken at an ISO of 1000 the resulting image is still of good quality.

We have learned so far that “aperture” controls the amount of light into the camera and “shutter speed” controls the amount of time the light is available to the sensor are the two controls to determine exposure. The third and final control for exposure is the “ISO” setting which controls the simulated sensitivity of the sensor to light. The ISO setting can affect the quality of your image in relation to digital noise, the lower the setting the less noise verses the higher the setting the more noise.

To find out how to set the ISO setting on your camera, refer to a previous lesson How to set your Camera’s; Aperture, Shutter Speed, and ISO.

Depending on the mode you have selected or the type of camera, you can control the ISO setting in full stops, typical values shown in bold, or 1/3 stop increments.

Now that we have learned all three controls, aperture, shutter speed and ISO as well as the creativity aspects of each, we now have the knowledge to discuss exposure in our next lesson.

“Motion” the creative control behind shutter speed

Up to this point we have chosen shutter speed settings based on freezing subjects, although this provides the sharpest image there are times where we may want to show some motion by allowing movement to be blurred which is the creative aspect of shutter speed.

f/6.3, 1/1000, ISO 400, @ 400mm

Even with fast shutter speeds with the intention of freezing the subject, very fast movement shows up as image blur. In the above image, the speed of North American humming bird wings average about 53 beats per second, that’s all the way down to all the way up 53 times. Notice that even at 1/1000 of a second shutter speed it is still not fast enough to freeze the motion of the humming bird’s wings. With the wings blurred the viewer feels a sense of motion. This is intentional as we want the viewer to see past the typical two dimensional photograph and feel more than just a bird suspended/frozen in mid air.

f/16, 1/80, ISO 100, @ 70mm

f/16, 20 sec, ISO 100, @ 70mm

Setting a slow shutter speed for a waterfall is one of the first techniques that we learn as photographers, as seen in the images above the shutter speed on the left is 1/80 of a second which is a relatively fast speed for moving water. Notice the chaotic movement and definition with the water at 1/80 of a second setting. By setting a much slower shutter speed, in this case 20 seconds, the image on the right now reveals the background and there is definition in the edges of the water which now shows a creamy look representing the movement, projecting a more relaxing feeling when viewing the image. When choosing slow shutter speeds you need to stabilize your camera, typically by using a tripod.

f/25, 1/30, ISO 100, @ 200mm

Another technique using slow shutter speeds for moving subjects is called “panning”. The difficulty is to obtain a low enough shutter speed, use the lowest ISO and a small aperture. The technique is to hold the camera steady while continually following the motocycle at the same speed while you press your shutter button. This technique gives the viewer a feeling of motion and of speed.

f/20, 1/15, ISO 100, @ 150mm

Using a tripod the panning technique can also be used with waves. The important technique here is to be at an angle of 90˚ to the water to follow the wave as it moves to the shore. Notice how the rugged shoreline is blurred and does not distract from the subject and the wave has pleasing smooth lines.

f/16, 0.6 sec, ISO 100, @ 150mm

If you are out late in the day or on a low light day, you may think there is not much to photograph. Get creative and try a panning image, again using a tripod, of the shoreline or at a beach, you may be surprised at the results.

Now that we have discussed the exposure and creative aspects of shutter speed, in our next lesson we’ll take a look at ISO.