Once you have mastered the automatic modes such as the automatic, program, shutter priority and aperture priority modes, that is the time you are ready to move on to the manual mode to further sharpen your skills. In manual mode, you get the complete control over the camera exposure as everything from shutter speed to aperture and ISO to white balance is managed by you.
Shooting in manual mode requires better understanding of lighting conditions and the relation between shutter speed, aperture and ISO. One must practice well to know as to how a change in the shutter speed will affect the aperture value or the ISO and vice-a-versa.
Once you get a fair knowledge about shooting in the manual mode, you would never switch back to automatic mode or shutter/aperture priority mode knowing that these modes would somehow restrict your creativity.
Decide your priority: Shutter Speed or Aperture value
The first thing that you have to decide while shooting on manual mode is whether to keep the shutter speed as the priority or the aperture value.
If you have to freeze the subject or wish to click a long exposure shot, then you will have to keep the shutter speed as the priority over the aperture value. Whereas, if you want to make sure that your photo has shallow depth of field (more blur effect) or deep depth of field (everything in focus) then you will have to prioritize the aperture value over the shutter speed.
Once you have prioritized one of the two elements of exposure triangle, you will then have to adjust the other element in such a way that your exposure scale is on ‘0’.
When you look through the viewfinder you will spot a scale which reads something like -2…1…0…1…2+ (in Canon) or +2…1…0…1…2- (in Nikon). This scale is the exposure scale which displays the exposure readings as measured by the camera light meter.
When you adjust the shutter speed, aperture and ISO values, the moment the scale comes to ‘0’ it means that as per the camera’s light meter that is the correct exposure. In case you feel that at ‘0’ you are getting underexposed photos, then you can adjust one of the exposure elements in such as way that the scale start to move towards ‘+’. Similarly, if you are getting overexposed photos then you can adjust the exposure in order to make the scale move towards ‘-‘.
Decide the shutter speed you want to choose
If you decide to set the shutter speed first, you will have to select the speed as per the nature of your subject and the way you want to capture it. The key factors which make you choose a specific shutter speed is the available light and the desired effect that you wish to capture.
Situation 1: When the subject is in motion and you wish to capture the motion in your photo then you will have to select a slow shutter speed. For example, if you wish to click light trails of moving cars, then you will have to use a slow shutter speed of lets say 5 seconds.
Situation 2: When the subject is in motion but you wish to freeze the motion in your photo, then you will have to select a faster shutter speed. For example, If you want to click a photo of a moving car and make it appear as still then you should be using a shutter speed of lets say 1/1000 second.
Situation 3: When the subject is stationary but you want the surrounding to appear in motion, then you will have to use a slow shutter speed lets say 1 second.
Situation 4: When the subject is stationary but the available light is low then also you will have to use a slow shutter speed in order to let in more light. By doing so, your stationary subject will be correctly exposed and would still appear sharp as it is still.
Thumb rule of selecting shutter speed for sharp results
There can be many other situation basis on which you will have to choose the required shutter speed. The thumb rule of choosing a shutter speed to get sharp results while clicking handheld is that the minimum shutter seed should be the same as the focal length of your lens (on a full frame camera, else multiply it by the crop factor). But using the image stabilization you can use a slower shutter speed by 2-3 stops, depending on the lens you are using.
But if this rule hampers your creativity or you wish to try something different, you can always choose a slow shutter speed by using a steady tripod.
Select the aperture value as per your desire
If your priority is to set the aperture value as per the nature of depth of field that you wish to capture, then you should first select the appropriate aperture value.
The amount of light that enters through the lens depends upon the opening of the aperture (diaphragm). The wider the aperture opening, the more will be the amount of light that enter the camera. Similarly, the narrower the aperture, the less would be the amount of light that enters the camera.
The f-stop is inversely proportionate to the opening of the aperture.
- The smaller the f-stop number = the bigger will be the aperture opening = more light will enter the camera
- The higher the f-stop number = the smaller will be the aperture opening = less light will enter the camera
Situation 1: If you wish to capture a photo with shallow depth of field (more blur effect), then you must choose a lower aperture value such as f/1.4 or f/1.8.
Situations 2: If you want to capture a photo with deep depth of field (everything in focus), then you should choose a high aperture value such as f/16 or f/22.
Once you have selected the required aperture value you then need to select the shutter speed in such a way that the exposure scale comes to ‘0’, this is how you would capture a photo with correct exposure.
But, if you first set the shutter speed as per your requirement and then choose the aperture value, you might have to compromise on the depth of field. Still if you want to go ahead and set both the shutter speed and aperture value as per your need, you can adjust the ISO value.
Select the ISO value as per the need and situation
Selecting the ISO value should be the third and the last thing you should be thinking of. The minimum the ISO value the less grainy and noisy your image would be, and as you increase the ISO value the grains start appearing in your photo and thus making it appear grainy and noisy.
You should always try and set the ISO to the minimum possible value, but there can be situation when you have to manually increase the value because of the light conditions or your personal choice to introduce grains.
Situation 1: You might have to increase the ISO value if the combination of the shutter speed and the aperture value that you have selected is going towards ‘-‘ on the exposure scale instead of appearing on ‘0’. By increasing the ISO value you can bring the exposure scale from ‘-‘ to ‘0’ and capture correctly exposed photo.
Situation 2: If you want to try something creative and introduce grains to your photo intentionally, then you can do so by increasing the ISO value.
Remember, every camera has its own range of ISO value up to which it can produce photos with no or less grains, but after a specific range the camera starts producing grains.