In this blog we look in detail at bracketing; the technique of taking multiple exposures and blending them to create high dynamic range photos. This technique is essential to take beautiful images of sunrise and sunset when the sun is in the frame. If you want to know how to do it, read on...
What is dynamic range?
Quite simply, dynamic range is the range between the darkest and lightest tones in a scene. If we are looking away from the sun, the dynamic range is relatively small; if we are looking towards the sun, the dynamic range will usually be very large. I.e. there is a large range between the brightest tones (around the sun) and the darkest tones (usually shadows in the foreground).
Why does dynamic range matter?
Our eyes are amazing, and when we look at a high dynamic scene, such as a sunrise or a sunset, we can usually see all of the details in the bright areas AND in the darker shadow areas. I.e. our eyes are capable of capturing a very high dynamic range. Although modern sensors are fantastic, they are still nowhere near as good are your eyesight, and therefore cannot capture all of the dynamic range we can see with our eyes. This is why often when we take a photo of a sunrise or a sunset, we end up with a photo that has either lost all of the detail in the bright areas (a big orange splodge around where the sun was!) or has lost all of the detail in the foreground (with everything very dark with no detail in the shadow areas).
Why does my phone take a better sunrise photo?
I've often had students ask me the question, and the answer is that your mobile phone is 'bracketing' (taking multiple exposures) and combining them to produce a high dynamic range image, all without you realising! If you want to be able to take more control, and create high dynamic range images with your 'proper' camera then read on!
How to bracket
This is one of those topics where I'm afraid the answer is that you will have to read your camera manual, as the method for bracketing will be different on virtually every camera make and model (and it's why I limit my photography workshops to 6 people, so that we have time to work with everyone 1-2-1 on things like this). However, the basic principles of how to bracket are below.
In bracketing, what we are trying to do is to take multiple photos (exposures) which cover all of the dynamic range in the scene (so it's only needed for high dynamic range scenes such as sunrise and sunset). Below are the basic steps to take:
1. Find you AEB (Auto Exposure Bracketing) settings. This is where you set how many photos to take, and how far apart (in exposure terms) each photo should be. E.g. for a very high dynamic range scene I might take 5 photos, 2 stops apart (a stop is a halving or a doubling of the amount of light). For a scene with less dynamic range (e.g. where the sun is partly obscured by cloud), 3 photos, 2 stops apart might be sufficient to cover all of the dynamic range in the scene.
On my Sony camera, this is done by selecting the 'Drive Mode' from the main menu and selection 'Continuous shooting' or 'Continuous bracketing'. There is then the option to choose from a number of combinations of how many photos to take and the exposure difference between them. In the photo below, I have selected 3 images, with 3 stops of exposure difference (3EV) between each shot.
2. Once you've set your AEB settings, you now simply press the shutter button. Instead of just taking one photo, your camera will now take 3 or 5 (depending on your AEB settings) photos each with a different exposure.
3. You now need to combine these brackets into a final high dynamic range image. If you have Adobe Lightroom, the process is very simple;
- Import the brackets into Lightroom and go into the Develop module.
- On the bottom thumbnail view, select all of your brackets.
- Right click on the displayed image and select Photo Merge > HDR. This will produce a new High Dynamic Range image which combines the exposures captured in the separate brackets. This HDR image can now be edited to produce your final photo.
Other points:
- Some cameras have an option to combine the brackets and produce a final high dynamic range image within the camera (like many camera phones)
- If you don't have the ability to bracket on your camera, you can do it manually e.g. by shooting in Manual mode and simply adjusting the ISO between frames to give a number of photos with different exposures (you will need a tripod to do this effectively so the camera doesn't move)
- If you don't have Adobe Lightroom, there are a number of free tools available for combining brackets, such as Picturenaut and FDRTools Basic.
An example
Below are a set of brackets that I took of a sunset. Below is the final HDR image created and edited in Adobe Lightroom.
The central bracket is the exposure that was set on the camera. As the camera can't capture the whole of the dynamic range, some detail is missing in the bright areas around the sun, as well as in some of the deep shadows on the cliff.
The left hand bracket is 2 stops (2EV) darker. This bracket captures more of the detail in the bright areas around the sun, but much of the shadow is lost.
The right hand bracket is 2 stops (2EV) brighter. Detail has now been lost in the bright areas around the sun, but more detail is now visible in the shadow areas of the cliff.
The image below is the High Dynamic Range image, edited in Lightroom, which has detail in the highlights around the sun, and in the shadows on the cliff. This is the purpose of using bracketing and helps to produce stunning, well exposed sunrise and sunset photos.
Want to jump-start your learning?
Don't forget that if you want some direct help with your photography, I offer a range of 1-2-1 photography courses for Devon based folks. If you're not nearby then I also offer residential weekends for beginners or intermediate photographers.
