In definition, exposure is the amount of light allowed to fall on each area unit of a photographic medium (photographic film or image sensor) during the process of taking a photograph. Exposure is measured in lux seconds, and can be computed from exposure value (EV) and scene luminance in a specified region.
A photograph is all about exposure. A properly exposed picture would ensure the details that you are trying to get out of a subject and showcase is actually visible. Also, exposure gives the dramatic effects that you would want to achieve in certain scenarios.
Now how would you achieve you desired level of exposure control. Luckily all cameras work on the same principles - the exposure triangle.
The three features that can help you control exposure are
1. Shutter speed
2. Aperture
3. ISO
Lets discuss about these in detail. But before that I would want us all to understand, how a camera works. The basics of the camera is explained in the blog here just in case you want to dig down the details.
These three features should be present in almost all the digital cameras. Film cameras will not have ISO, instead it should have film sensitivity.
Shutter Speed
Every camera works on this simple feature, allow light to fall on a sensitive medium and particular amount of time. In very simple terms the amount of time for which the light falls on the medium is the shutter speed. Although, this definition is only for our understanding. Mechanically speaking, a camera uses a shutter to shield light from falling on the recording medium. This shutter is released or opened when we click the camera button to take a photograph. Shutter opens for a predetermined amount of time, during which the light falls on the medium and then the shutter closes again stopping light to fall on the medium. The moment for which the shutter opens is called the shutter speed. It can range from 30 seconds to 4000th of a second(obviously this depends on the camera) or even higher.
Aperture
Every camera works on this simple feature, allow light to fall on a sensitive medium and particular amount of time. Simply said, the amount of light that falls on the recording medium is the aperture. Mechanically putting, an aperture is the hole through which the light is allowed to fall on the recording medium. The size of this hole can be increased or decreased based on our requirements. This can range from f1.8 to f22 where 1.8 is the biggest (This depends on the lens attached).
ISO
Every camera works on this simple feature, allow light to fall on a sensitive medium and particular amount of time. The ISO of a sensor is can be said as the sensitivity of the sensor or the recording medium, to light. As light is incident on the sensor it triggers an electronic event (for simplicity). This event is the information that is to be recorded. The information is nothing but the photographic image through light rays falling on the sensor. Now, the intensity of the event can be controlled and hence the sensitivity of medium to light. This ranges from ISO 100 to 6400 and higher(depending on the sensor).
We can now safely assume now that at least the basics of these pillars of exposure in photography are a bit clear. I still have a question, even if I understand these basic concepts in terms of a camera, still, how is my exposure getting effected. Even before we answer this question we should understand exposure in terms of a photograph.
There may be many articles online that explains these fundamentals. I as a beginner went through many of them to understand exposure. What many of these commonly found articles do is that they explain about these in detail. I found it very difficult to relate it to the pictures I took. It was very easy for me to understand how a shutter works and how an aperture behaves and even for you I trust these would not be an issue at all now. Try and relate these with the pics you would want to click.
Exposure is nothing but how bright or dark your image would be when it is captured. An ideal scenario is perfect exposure, neither too bright or too dark. This can be well easily said but very difficult to perform. Exposure is dependent on the light around. Night scene would mean very less light and noon would mean very bright light. Different scenes would mean different light conditions and hence exposure varies accordingly. The above three parameters would come to our rescue here. All the above three parameters would control exposure for us and give us our desired result. Remember the combination of all the above would give us a perfectly exposed picture.
Shutter would ensure the time frame for which the light falls on the medium. The more the time for which the light falls the more the exposure. Hence, the less the shutter speed the more the exposure. For example, a shutter opening for 30 seconds is definitely more exposed than a shutter for 5 seconds.
Aperture allows the quantity of light to fall on the medium. Hence, the wider the aperture the greater the exposure. f1.8 is far more exposed than f16.
ISO is medium's reaction to light. The more the ISO the more the exposure. Therefore an ISO 1600 would mean more exposed pic than ISO 100.
In terms of a photograph, if you want you picture to be brighter then either reduce your shutter speed or increase aperture or increase ISO. You could also work in a combination by altering any of these.
The works of these three and their play in photography will be detailed out later. For ease in understanding we should know that there are effecting the exposure in the ways we discussed here.
Exposure would continue in the next article.
A photograph is all about exposure. A properly exposed picture would ensure the details that you are trying to get out of a subject and showcase is actually visible. Also, exposure gives the dramatic effects that you would want to achieve in certain scenarios.
Now how would you achieve you desired level of exposure control. Luckily all cameras work on the same principles - the exposure triangle.
 |
| Exposure Triangle |
1. Shutter speed
2. Aperture
3. ISO
Lets discuss about these in detail. But before that I would want us all to understand, how a camera works. The basics of the camera is explained in the blog here just in case you want to dig down the details.
These three features should be present in almost all the digital cameras. Film cameras will not have ISO, instead it should have film sensitivity.
Shutter Speed
Every camera works on this simple feature, allow light to fall on a sensitive medium and particular amount of time. In very simple terms the amount of time for which the light falls on the medium is the shutter speed. Although, this definition is only for our understanding. Mechanically speaking, a camera uses a shutter to shield light from falling on the recording medium. This shutter is released or opened when we click the camera button to take a photograph. Shutter opens for a predetermined amount of time, during which the light falls on the medium and then the shutter closes again stopping light to fall on the medium. The moment for which the shutter opens is called the shutter speed. It can range from 30 seconds to 4000th of a second(obviously this depends on the camera) or even higher.
Aperture
Every camera works on this simple feature, allow light to fall on a sensitive medium and particular amount of time. Simply said, the amount of light that falls on the recording medium is the aperture. Mechanically putting, an aperture is the hole through which the light is allowed to fall on the recording medium. The size of this hole can be increased or decreased based on our requirements. This can range from f1.8 to f22 where 1.8 is the biggest (This depends on the lens attached).
ISO
Every camera works on this simple feature, allow light to fall on a sensitive medium and particular amount of time. The ISO of a sensor is can be said as the sensitivity of the sensor or the recording medium, to light. As light is incident on the sensor it triggers an electronic event (for simplicity). This event is the information that is to be recorded. The information is nothing but the photographic image through light rays falling on the sensor. Now, the intensity of the event can be controlled and hence the sensitivity of medium to light. This ranges from ISO 100 to 6400 and higher(depending on the sensor).
We can now safely assume now that at least the basics of these pillars of exposure in photography are a bit clear. I still have a question, even if I understand these basic concepts in terms of a camera, still, how is my exposure getting effected. Even before we answer this question we should understand exposure in terms of a photograph.
There may be many articles online that explains these fundamentals. I as a beginner went through many of them to understand exposure. What many of these commonly found articles do is that they explain about these in detail. I found it very difficult to relate it to the pictures I took. It was very easy for me to understand how a shutter works and how an aperture behaves and even for you I trust these would not be an issue at all now. Try and relate these with the pics you would want to click.
Exposure is nothing but how bright or dark your image would be when it is captured. An ideal scenario is perfect exposure, neither too bright or too dark. This can be well easily said but very difficult to perform. Exposure is dependent on the light around. Night scene would mean very less light and noon would mean very bright light. Different scenes would mean different light conditions and hence exposure varies accordingly. The above three parameters would come to our rescue here. All the above three parameters would control exposure for us and give us our desired result. Remember the combination of all the above would give us a perfectly exposed picture.
Shutter would ensure the time frame for which the light falls on the medium. The more the time for which the light falls the more the exposure. Hence, the less the shutter speed the more the exposure. For example, a shutter opening for 30 seconds is definitely more exposed than a shutter for 5 seconds.
Aperture allows the quantity of light to fall on the medium. Hence, the wider the aperture the greater the exposure. f1.8 is far more exposed than f16.
ISO is medium's reaction to light. The more the ISO the more the exposure. Therefore an ISO 1600 would mean more exposed pic than ISO 100.
In terms of a photograph, if you want you picture to be brighter then either reduce your shutter speed or increase aperture or increase ISO. You could also work in a combination by altering any of these.
The works of these three and their play in photography will be detailed out later. For ease in understanding we should know that there are effecting the exposure in the ways we discussed here.
Exposure would continue in the next article.
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