I remember when I received my first digital SLR. A Nikon D7000. I was so proud of it. For the next week or so, I took it everywhere I went, disregarding the hassles of carrying a long lens and a bulky DSLR with me at all times. It was my best friend. Then I realized there was something wrong with the images that I shot. They somehow did not quite come out the way I expected them to. Though there were times when they did come out great, it was more of a hit and miss kind of a thing. You fire enough frames, a few turned out great and most of them hit the trash can. I could never figure out the reason why this happened. I was frustrated not knowing why I couldn’t control the output even though I managed to reach a good spot and made a fairly decent composition.
Then something struck me. I haven’t been fiddling with the settings on my camera. For example, what was the meaning of the letters M, or S or even A? Why does the image take longer to get ‘recorded’ in some cases, especially when I am shooting in darker conditions and inside my home compared to when I am shooting outdoors? Why does the flash pop-up in certain situations automatically? Why is the image blurry at time when I am trying to photograph moving subjects? Questions like these flew out of my mind at all times without any satisfactory answers. I realized I am missing something and that there was a lot more to photography than just pressing the shutter release.
Thus, started a steady and long process of educating myself. I spoke to every member in my extended family who were interested in photography. I picked their brains. I picked the brains of my friends and then finally I took recourse to the internet. I finally found an endless repository of knowledge, inspiration and answers to questions that I had but nobody could answer. I realized the mistakes that I had been doing, and that I needed to master the controls on my DSLR before even trying to aim at something.
Switching to aperture priority
One of mistakes that I had been doing was I was shooting on the Auto mode. The auto mode is a smart shooting mode no doubt. It tends to do a fair job in most ‘normal’ shooting situations. You want a group photo, the auto mode will work well. You need to shoot an average landscape photo, again the auto mode does a great job of it. But as soon as you want to shoot something other than average, let’s say a low light portrait shot, a long exposure of a brook, or even the Milky Way, the auto mode falters and comes a cropper. It stutters, huffs and puffs and at the end it fails to produce an image that we could ever like.
At many times you need to push yourself beyond your comfort zone and making good images is just one of those moments. Thus, the need to take your camera out of the Auto mode and into one of the more creative modes, namely Aperture priority mode.
Aperture priority is a mode that will allow you to adjust the depth of field of your shots. Set the main mode dial (circular dial at the top right or left of the viewfinder) to A (or Av). Then turn the main command (or sub-command) dial till you see the numbers change on the viewfinder (or the LCD screen, if you have the menu turned on) to something like f/3.5, f/4, f/5.6 and so on. With each increasingly smaller fraction the opening of the lens becomes smaller.
When the lens opening gets smaller, it does two things really. First, it allows less and less light to get in. Second, it makes the depth of field get bigger and bigger. Every time you select the next smaller (or larger) fraction, the size of the lens opening becomes a stop smaller (or larger). This means you are letting in less light (or more).
When you switch to aperture priority and select an aperture, your camera automatically selects the right shutter speed for the shot. This it does using something known as metering system. Metering system has a long and technical definition. We are not going to go into that. In plain English it means the camera can detect how much light is necessary to make a good image of the scene.
Based on the metering mode selected it will automatically set the right aperture and the shutter speed necessary to make a decent exposure. In aperture priority mode, you select one of the variables (namely aperture) and the camera selects the other.
Using the shutter priority mode
In the previous paragraph we learnt how by using the aperture priority mode we can modify the depth of field of our images as well as control the amount of light that is captured. But at times you may not need to control both the depth of field as well as the amount of light that is captured. May be just the amount of light. So how do you do that? While controlling both aspects require you to shift to manual mode, which we will discuss next, controlling just the amount of light with the depth of field left to be controlled by the camera, you need to switch to shutter priority mode.
Shutter priority mode is labelled as ‘S’ or ‘Tv’ on some cameras. When you select shutter priority mode you have the creative freedom to choose whatever shutter speed that you may want. Shutter speed denotes the length of time for which the shutter remains open when you press down the shutter button. The camera selects the corresponding applicable aperture and gives you a balance exposure.
So, which mode to choose? It depends on the type of photo that you need to shoot. Let’s take this discussion to manual mode and find out more before deciding.
When To Switch To Manual Mode And Back To Auto Mode
Half the time pro photographers would have their cameras set to aperture priority mode. This is because they are mostly worried about the depth of field of their compositions. Shutter speed is something that they rely on their cameras to take care off, which most of the times are in the ball park. However, that being said, the camera, or rather the camera’s metering system cannot be relied on at all times; and therein lies the need to use the manual shooting option.
The manual shooting option basically is about exercising ultimate creative freedom. The option to choose both the aperture and the shutter speed on your own. This allows you to choose the right exposure for a scene, which may not always be what is ‘average’ but what the requirement is in terms of creative expression. We will come to that later.
Let’s say you want to control both the depth of field of your image and the amount of light that gets to the sensor. Let’s say you are staying at one of the top floors of a hotel in a city you are visiting. You look down the window and see the bright lights and decide to make an image. The problem is auto mode will almost always give you an incorrect combination of the right aperture and shutter speed combination (together aperture and shutter speed is known as exposure value).
In a situation like this you need to be able to manually select the shutter speed and aperture combination yourself. We have already learnt that small aperture (smaller fraction) tantamount to a larger depth of field. That’s exactly what you need in this case. So, first thing set your camera to manual mode. Next, set a small aperture something like f/8 to start off. Next thing you need a slightly longer shutter speed. I’ll explain why. With a slightly longer shutter speed, say 3 seconds, you give your camera that much more time to capture long trails of light from the vehicles. The resulting image is a lot more appealing than a quick snapshot.
Thus, aperture priority, shutter priority and manual mode, each have their own applicability in photography. You need to take a call as to what your requirement is in terms of the type of image you want to capture and accordingly select the right shooting mode. Even auto mode has its own applicability. It is the best mode when you don’t have time to make careful exposure adjustments and just need to capture an image.
Controlling The Third Parameter Of Exposure Triumvirate – ISO
Most of the times I leave my camera on Auto ISO. It does a fantastic job of picking the right ISO for a good exposure. At times however, auto ISO struggles to read my mind. Such as when I need to collect a lot of light at an instant. Say, I am photographing the Milky Way I need to shoot at the widest f-stop possible, plus the higher ISO that my camera is capable of shooting without drowning out the image in noise. The ISO button allows me to select the ISO that I need.
For most purposes you can leave it to auto ISO as I do. Except when you need it otherwise. Let’s take another example. Let’s say that you are photographing your significant other at a place that does not have a lot of ambient light going. There are two ways of countering for the lack of light. First is to use a small f-stop, something like f4 or wider. The other option would be to use a slow shutter speed. In other words, drag the shutter speed so that the sensor gets a long time to collect a lot of light.
The problem with the first approach is that not all lenses can open to f/4 or wider. Only primes or very expensive zoom lenses, and that too wide-zooms open to f/4 and wider. Dragging the shutter speed also has a problem and that is it tends to create image blur. The solution is in using a higher ISO number.
ISO isn’t a parameter that controls exposure. It is something that controls the sensitivity of the sensor to light. Each increasingly higher ISO number has the effect of doubling the exposure. So if you shoot at ISO 100 and get a good exposure using f/4 and a shutter speed 1/100, at ISO 200 you could either shoot at f/5.6 and a shutter speed 1/100 or aperture f/4 and shutter speed 1/200. Ideally when you need to avoid image blur you should select the faster shutter speed.
Selecting The Right Metering Mode
Your camera, by default, ships with the matrix metering mode set. Before we get into the details of matrix metering mode let’s first understand what metering mode actually is. I have already described before that every digital camera has what is known as a mechanism to judge how much light is necessary in order to capture the right exposure. This mechanism uses a variety of technology to assess the luminosity of the scene. It is known as the metering system. This system can be tweaked to work in 3-4 modes. These modes are center-weighted, partial, matrix and spot metering. Most cameras have the three modes namely matrix, spot and center-weighted. Some camera systems like Canon have the partial metering mode. Each of these metering modes are ideally suitable for a particular type of photography.
Matrix mode is suitable for shooting landscapes. This takes into account the luminosity of the entire scene, something which is ideally suitable for the purpose of landscape photography, and then assesses the right exposure value. Center-weighted is a mode wherein instead of the entire frame, emphasis is placed only on the center of it. As you can imagine this mode is ideally suitable when you have your subject right at the center of the frame.
Spot metering is yet another interesting metering mode. This only assess the focusing point and the immediate area of the point. The overall area of the frame considered in spot metering is no more than 5%. This mode is ideally suitable when photographing small subjects and especially where you need to meter for something like a small piece of jewelry, something middle-gray in the frame and so on.
Selecting The Right Focusing Mode
Selecting the right focusing mode can make or break your images. If you are caught with the wrong focusing mode you wouldn’t have enough time to readjust when the opportunity presents itself. There are two basic focusing modes on your camera – auto and manual. It is always best to set your camera to auto when in doubt. The reason is the camera can do a far better and far quicker job of giving you an accurate focus lock than you could by manually turning the focus ring. I am not saying that you have bad eyes or poor hand-eye co-ordination, but the odds are in favor of auto focusing most of the times. To get a better focus lock, ensure that the center cross-type AF point coincides with your point of focus. That way the camera’s auto-focusing system would be able to accurately lock focus basically at the blink of an eye.
There are 3 types of auto-focusing modes on all DSLR cameras. These would be continuous auto-focusing, single-shot auto-focusing and an auto mode where the camera determines which type of auto-focusing should be ideal for the scene. These are named differently by different camera manufacturing companies but their functionalities are the same. Let’s take a look at them and find out when to use which.
99% of the time I have auto-focusing set to single-shot. Single shot auto-focusing method acquires focus when you half-press the shutter release button. It is marked by the letters AF-S on Nikon systems. The camera uses tiny phase detection AF points located at the bottom of the camera to acquire focus. With single shot auto-focus the point of focus acquirement does not change when you move the camera around after locking focus. Let’s say you want to capture an off-center composition of a flower. You use the center focusing point on your camera to lock focus. Then you move the camera slightly towards the right to make the composition off-center, without letting go the shutter release. Focus is locked at the original point / distance. Now if you fully press down the shutter release the image will be made with the focus locked on the flower. This is the advantage of single-shot auto-focusing.
However, single-shot auto-focusing is not a type of focusing that works in all situations. At times when the subject moves around you would need to continuously adjust and reacquire focus. This is difficult to accomplish manually. The solution is in using continuous autofocusing mode. Continuous autofocusing or continuous servo focus, as is termed by Canon, works by passing focusing information from one focus point to the next when the subject keeps moving. This mode is ideal even in the above example where you are photographing the flower. How? Let’s say you are photographing the flower on a slightly windy day. The flower is continuously moving about in the wind. Continuous auto-focusing will allow you to retain a good focus lock in such situations.
In the second part of this article we shall cover things like using the AF point selector option for precise off-center composition, using the technique of back-button focusing and how to use manual focusing override among other techniques.