Do you use exposure compensation?
If you don’t and you start using it you will be astounded by the impact that this little dial/button/touch screen function can have on your images.
This blog post explains the basics of Exposure Compensation.
Introduction to exposure compensation
Do you often find that your images look to bright or too dark? Do you struggle with getting your wildlife photographs exposed correctly? If so then you need to use Exposure compensation to help you improve your wildlife photography Images.
Exposure Compensation is an easy and simple technique that you can use to improve your photography.
If you want to have more control over how you expose your images, you might think that you need to use Manual mode and all of the complexities that come with it — but this isn’t true.
I shoot in Aperture priority (with Auto ISO and a minimum shutter speed selected for 1/1000s) and regularly use exposure compensation as required.
Exposure Compensation is a way to tweak your camera’s judgement and get exactly the results that you want.
(Mute Swan f4 1/1000s ISO 90 -1.33 exp compensation)
What is exposure compensation?
Exposure Compensation is a way of tweaking the exposure that your camera thinks is ‘perfect’.
When you shoot in Program, Aperture Priority mode (Av or A), or Shutter Priority (S or Tv), your camera makes intelligent calculations to figure out which settings to use to get the perfect exposure.
This process is called metering.
In Program mode, the metering looks at the varying amount of light hitting the sensor and figures out what aperture value, shutter speed, and ISO are required in order for the brightness to average out at a specific shade of grey.
This shade of grey is often called “middle grey” or “18% grey” and is used by all manufacturers as the basis of what makes a good exposure — trying to get as close as possible to what you see with your own eyes.
Metering isn’t perfect, however. For example, strong backlighting such as shooting portraits with a setting sun behind, or snowy scenes can confuse the camera, making your photographs too dark.
As a result, your backlit portraits might look like silhouettes, and snowy scenes may end up looking murky.
This is where Exposure Compensation can be useful.
(Mountain Hare f4 1/1000s ISO 160 +1.6exp compensation)
Exposure Compensation allows you to influence the camera’s judgement slightly, telling it to make everything brighter or darker.
You can use Exposure Compensation to tell the camera to meter a scene based on a shade of grey that is darker or lighter than the 18% grey that it would use normally.
When you increase Exposure Compensation (e.g., +1, +2), your images will become brighter, lifting your shadows.
When you decrease Exposure Compensation (e.g., -1, -2), your images will become darker, protecting your highlights.
Which Camera Modes does Exposure Compensation work in?
Exposure Compensation can be used in almost every mode. It’s useful to know how Exposure Compensation varies in its behaviour depending on which mode you are shooting in.
It’s easiest to begin explaining this by understanding Aperture Priority mode and Shutter Priority mode and to imagine that we are shooting a scene where the light is not changing.
Aperture Priority Mode
In Aperture Priority mode, you set your aperture and your camera automatically selects a shutter speed according to the brightness of the scene. When you increase your Exposure Compensation by +1 to make your images brighter, your camera will halve the shutter speed in order to let in twice as much light.
| -1 | 0 | 1 | |
| ISO | 100 | 100 | 100 |
| Shutter Speed | 1/1000 | 1/500 | 1/250 |
| Aperture | F4 | F4 | F4 |
For example, if you have chosen an aperture of f/4 and an ISO of 100, let’s say that your metering system has automatically chosen a shutter speed of 1/500th of a second.
If you then increase your Exposure Compensation by +1, your camera will drop the shutter speed to 1/250th. This doubles the amount of light entering reaching the sensor.
If instead, you were to set your Exposure Compensation to -1, your metering system will increase the shutter speed to 1/1000th. This halves the amount of light reaching the sensor.
This is not ideal as I want to ensure that I have control of my shutter speed and I don’t want the camera to make it slower if I am trying to correctly balance my exposure. There is a way around this which I will cover later.
Shutter Priority Mode
In Shutter Priority mode, you set your shutter speed and your metering system automatically selects an aperture according to the brightness of the scene.
As before, increasing the Exposure Compensation to +1 will make your images brighter, but this time the camera will double the size of the aperture to let in twice as much light.
For example, if you have chosen a shutter speed of 1/500th and an ISO of 100, let’s say that your metering system has automatically chosen an aperture of f/5.6
| -1 | 0 | 1 | |
| ISO | 100 | 100 | 100 |
| Shutter Speed | 1/500 | 1/500 | 1/500 |
| Aperture | F8 | F5.6 | F4 |
If you then increase your Exposure Compensation by +1, your camera will double the size of the aperture by opening it up to f/4.
The opposite is true, decreasing the Exposure Compensation by setting it to -1 would cause your camera to halve the size of the aperture by closing it down to f/8.
Again this is not ideal in wildlife photography. If I want to have the complete control over my aperture and the relevant depth of field that I require in my image. I would not recommend this set up.
Program Mode
How Exposure Compensation affects the exposure when using Program mode depends on the camera. You might find that it always changes your exposure, or you might find that it does nothing at all.
On some cameras, Exposure Compensation only works in Program mode if you’re not using Auto ISO.
Again I would not recommend this.
Manual Mode
Because you are setting the variables yourself, Exposure Compensation will not do anything to your image if you try to change it while shooting in Manual mode.
However, if you are in Manual mode and you select Auto ISO, Exposure Compensation will vary the ISO to give different exposures.
How do you set Exposure Compensation in Manual Mode?
In Manual mode, you choose the shutter speed, aperture, and ISO. Because there is no variable that the camera is setting automatically, changes to Exposure Compensation will not have any effect.
However, there is an exception.
Slightly confusingly, the Manual mode on most digital cameras still gives you the option to set the ISO to Auto. This means that the camera is now calculating the right exposure and changing the ISO accordingly.
As a result, Exposure Compensation will have an effect in Manual mode if your ISO is set to Auto.
Increasing the Exposure Compensation to +1 will cause the camera to double the ISO, creating a brighter image.
Decreasing the Exposure Compensation to -1 will cause the camera to halve the ISO, creating a darker image.
| -1 | 0 | +1 | |
| ISO | 100 | 200 | 400 |
| Shutter Speed | 1/500 | 1/500 | 1/500 |
| Aperture | F4 | F4 | F4 |
This is also the case if you shoot with Aperture Priority and use Auto ISO and set a minimum shutter speed. I shoot in Aperture priority and set a minimum shutter speed of 1/1000 second this effectively means that the camera will always select an ISO to give me my chosen aperture and my minimum shutter speed of 1/1000 second.
But if I then apply exposure compensation the camera will not change the shutter speed at all – It will decrease or increase the ISO.
Therefore I am using ISO to balance my exposure and also to add the creativity that I want in my images (more on this later).
So I recommend that you use Exposure Compensation with Auto ISO in either manual mode or aperture priority if you are able to set a minimum shutter speed when using Auto ISO.
(Fishing Osprey f5.6 1/1000s ISO 720 -1.6exp compensation)
How is Exposure Compensation measured?
Exposure Compensation is measured in relation to Exposure Value, sometimes referred to as “stops” and often divided into thirds.
Exposure Value is a scale that measures the amount of light that is hitting your camera’s sensor.
In terms of Exposure Compensation, the exposure that your camera thinks is “normal” is always 0 (zero) and most cameras then allow you to adjust this by increments of 1/3 of a stop, usually to a maximum of 3 stops.
Exposure Compensation in Action – Over exposure
0 Exposure Compensation
Too Dark – as the background is very bright the camera has balanced the exposure by trying to reduce the brightness
Some detail is in the image still, but it would result in increased noise in the shadows when processed.
+1 Exposure Compensation
Nearly the correct exposure, possibly slightly too dark, but this can easily be tweaked in post processing.
By exposure compensating by 1 stop it has revealed more detail in the shadows. This one would have looked best if reviewing the histogram
+2 Exposure Compensation
Over exposed – it can still be processed to even out the exposure, slight clipping of the highlights in some part of the image. By overexposing by 2 stops it has revealed a lot more detail, but it has also caused the whites to be too bright. This one would have looked the best if trusting the screen on the back of the camera
Exposure Compensation in Action – Under exposure
0 Exposure Compensation
Too Bright – This was shot in very harsh sunlight and the camera has tried to give an even exposure but the highlights on the otter’s fur and the water are blown.
Impossible to pull back the highlights. Image not useable.
-0.67 Exposure Compensation
A much better image to work with.
Slight clipping on the highlights where the water is. But is workable. Has retained the detail. This would be the image that looks best if reviewing the screen on the camera.
-1 Exposure Compensation
Appears too dark – However the detail has been retained in the shadows and in the highlights and therefore is the best image to work with in post processing. This one would have looked the best if reviewing the histogram.
Exposure Compensation if used correctly will really help you get the exposures that you are looking for. Generally for normal Exposure Compensation you will be between -1 and +1 values. After a while and the more you use it – the easier it will become and you will start to see the types of lighting situations that you will need to use exposure compensation in.
So now you know the basics and how to use exposure compensation to correctly balance your exposures read this blog on the creativity of exposure compensation and learn how to create:
- Pure white backgrounds
- Pure black backgrounds
- Shoot for shadows
- Add contrast to your images even when the light is flat
- Change your background colours
- Make your subjects pop
- Look for and create natural vignettes
If you are interested in learning more about Camera Settings and Exposure or specifically Exposure compensation then why not:
Get a copy of my Ebook available on Amazon – The Ultimate Beginners Guide to Wildlife Photography – From Taking a Shot to Capturing a Moment.
Or enrol on my online training course – available on Udemy
Or Join me on one of my workshops specifically designed for beginners