In photography, exposure is the amount of light per unit area reaching a photographic film or electronic image sensor, as determined by shutter speed, lens aperture and scene luminance.
I find that a lot of friends are in this stage where they want to use the manual mode of their camera but they find it quite daunting so I thought I am going to try to explain it the way I understand it.
Manual mode for me it means freedom, it means that you can control how much light goes into your camera, and by controlling the amount of light that goes into your camera, inevitably you have more control over the outcome and the whole photography experiment becomes more exciting and creative.
I am going to try to write this in a sort of bullet point form and divide it into 4 steps. So, here it goes:
Set your camera in Manual Mode.
The target is the pictures you take to have the ‘Correct exposure’.
What does that mean?
It means that your picture is not:
a. Underexposed: failure to record details in the darker areas of the image (i.e. the image is too dark).
b. Overexposed: failure to record details in the brighter areas of the image (i.e. the image is too bright)
How will you achieve this target?
By adjusting the following 3 things on your camera:
Aperture is the hole or opening by which the light enters your camera. You can control how big or small you want the aperture to be. The bigger the aperture the greater the amount of light that enters the camera. The greater the amount of light that enters the camera the brighter the photo will be.
How we measure the size of aperture?
The aperture size is measured on what is called the f-stop scale.
F-stop: F/2, F/2.8, F/4, F/5.6, F/8, F/11, F/16
Remember: The greater the number the smaller the size of the aperture.
Why? Because the f number is the number you divide the focal length of your lens to get the diameter of the aperture.
For example, for an F/2 aperture and a 50mm (focal length) lens when you divide 50 by 2 then the aperture will have a diameter of 25mm, but for an F/22 aperture the same 50mm lens will get you an aperture with a diameter of 2.3mm. So, it is obvious that the 25mm diameter is much bigger than the 2.3mm and as a result more light into your camera.
A bit extra: You can also use aperture to control the depth of field of your images, you know that blurriness at the background you see sometimes in pictures, that’s shallow depth of field.
• Shutter speed:
Shutter speed is the amount of time the shutter is open and the camera sensor is exposed to light. You can control for how long you want the shutter to be open. The longer the shutter is open the greater the amount of light that enters the camera. The greater the amount of light that enters the camera the brighter the photo will be.
How we measure the shutter speed?
The shutter speed is measured in fractions of a second.
Fractions: 1/30s, 1/60s, 1/125s, 1/250s, 1/500s, 1/1000s
Remember: The smaller the denominator the longer the shutter will stay open and so more light into the camera.
A bit extra: You can also use the shutter speed to capture movement, you know when you take a picture of a moving car and you see those lines of light following it, or to freeze a scene.
ISO is the sensitivity of your camera sensor to light i.e. how much light the sensor absorbs from the environment to light the picture.
I call ISO the “weather question”. It is like when you ask someone “What is the weather like today?” If it is sunny and bright then the sensor doesn’t have to be very sensitive to light so you set your ISO at a lower number, if it is night or you are indoors then your sensor needs to be more sensitive to absorb all the light available.
How we measure the ISO?
ISO: 100, 200, 400, 800, 1600, 3200
Remember: The bigger the number the more sensitive the sensor to light, so for a bright sunny day an ISO of 100 or a 200 would be more appropriate, for indoors maybe a 400 or 800.
A bit extra: Be careful though because if you set the ISO too high your picture will get noisy and you don’t really want that.
And now, the most difficult part, you have to balance the 3 elements (Aperture, ISO and Shutter speed) in such a way that you get the correct exposure.
To start with, I would say go with, trial and error. Professional photographers of course have some tricks or routines to get the exposure they want as quickly as possible but I think when you start using your camera in manual I find trial and error to be the best (more fun) way. It will help you understand better what you like and what you are looking into a photo.
Also, correctly exposed pictures are quite difficult to achieve and sometimes you need to prioritise, ask yourself whether you need better exposed details or shadows, what is more important for the purpose of your picture. Sometimes it is just a matter of like, you may like your pictures under or over exposed because this adds to the story you want to tell.
I want to close this with a few observations and misconceptions I had before starting to learn a bit more about photography. So, here it goes:
The fact that you have your camera in manual mode it doesn’t make your pictures automatically better. It means that your pictures will get a lot worse before they even get a little bit better. It takes time! It is all about practice! Perseverance remember?
Your phone is just fine to use for taking pictures, sometimes is better than even using a camera. And, for street photographers, sometimes using your phone camera helps in capturing the moment you are looking for without capturing unnecessary attention!
Please don’t feel guilty using the preset modes on your camera and especially when you are on holiday and you don’t want to spend most of the time playing with ISOs and apertures etc. Having said that, I, personally, find this quite fun but the people with you may not find it as fun!
Finally, the more I get involved with this photography world I realise that everyone has a different opinion on what a good picture is. But you know what? It doesn’t really matter, what matters is that you know what you need out of your pictures!
Anyway, these are my opinions! Now, take your camera off auto mode and go make some pictures! And have fun!
Feel free to share and comment!
Thank You for reading!
1. Manual mode
2. Target: Correct exposure
3. Aperture, Shutter speed, ISO
And my notes: