What is HDR Photography?
A lot of us have heard the term HDR photography and some of us may associate it with supersaturated very dramatic looking photos. While those stylised photos can be the desired result I’m here today to explain the concept of HDR photography and to bring you some good news that when used right, HDR photography can be a powerful and easy to use tool in your landscape photography. Let’s dive in!
First things first what does it stand for? HDR is an acronym for High Dynamic Range. Simply explained HDR photography normally consists of 3 or more exposures of the same scene to ensure that you capture enough detail in the shadows all the way through to the highs. Once combined using software (a process which has been made very easy by Adobe Lightroom) you are left with one image that has maximum detail in both the shadows and highs!
Let’s look at a simple example!
Let’s quickly think of a scenario (one that you can test out at home) where using HDR photography will achieve better results than just taking one exposure. Grab your camera and pick any room in your house. Set up your camera on the opposite side of the room that faces the window. Light is going to flood into your scene from the window. To protect the highlights in this scenario you are going to have to take in less light than needed to get detail in the shadows. To get enough detail in the shadows your highlights are going to be extremely blown out. This is because the dynamic range between the highs and the shadows is far too great to capture in one single exposure. This is the perfect time to take multiple exposures! Take one exposure that collects all the detail in the shadows followed by one exposure that collects all the details in the mid-range and finally take one more exposure that collects all the details in the highs. (most modern cameras can be set to do this automatically)
When these three exposures are merged together in your chosen software editor you will be left with one image that contains all of the details in the shadows, mids and highs!
Most modern cameras have an auto function that allows you to set how many exposures you want to take, providing the number (excluding the mid-range value) can be divided by 3. On the Exposure Value Meter the extra images you add to the mid-range exposure simply show as a plus and a minus. A common choice is +3 and -3.
To set up for three exposures, the values should be -3, 0, +3
To set up for seven exposures, your values should be -3, -2, -1, 0, +1, +2, +3
It may sound a little complicated but once you play around with your camera and see how the settings work it’s normally pretty easy and quick to set up.
So what happens after you take several exposures of the same scene? This part is surprisingly easy. There are several software solutions to help you do this. I personally use Lightroom so I’ll stick with that for the purpose of this blog post. After exporting your images into Lightroom you go ahead and find the first and last image.
Highlight all of the images that will make up the HDR image and right-click on one of them. Scroll down to ‘Photo Merge’ and hover over it to get the drop-down menu.
Simply click on HDR. (or just press Cmd-h on a Mac or Ctrl-h on a windows) A preview window with some options will appear.
The ‘Auto Align’ option will automatically align all of the photos together, the images will be slightly cropped so you may lose some pixels. This setting is useful if the images being merged have slight movement from shot to shot (say you shot handheld for example).
The ‘Auto Settings’ performs the same auto changes to the light and saturation that would be made if you selected auto on the exposure control panel.
‘Deghost Amount’
Sometimes, after the exposures are merged, some areas in the merged image may appear unnaturally semi-transparent. Select one of the following deghosting option in the HDR Merge Preview dialog box to correct these anomalies: None, Low, Medium, or High. Try Low deghosting first to obtain a clean merged image. Try higher settings if necessary. Avoid using if your preview is free of ghosting artifacts.
Low: Cures little or minor movement between frames
Medium: Cures considerable movement between frames
High: Cures high movement between frames
You can preview the effect of these settings right within the dialog box. If necessary, choose to view the deghost overlay.
To group the exposure-bracketed images and the HDR image into a stack (after the images are merged), select the Create Stack option. The merged HDR image will be displayed at the top of the stack.
Click ‘Merge” and voila, your HDR image is ready to be edited. Once combined your image will retain all of the information from the three images allowing you to get a nice balance between the shadows and highs without having to make any sacrifices.
*Tip: It is easy to get carried away while editing a HDR photo, you have so much detail all the way from the shadows to the highs that it is easy to make the photo look unnatural. Less is definitely more when editing a HDR photo, go easy on those sliders!*
Now that we understand what HDR photography is and technically how to use it, let's look at how it can become a powerful tool to help you to produce killer landscape shots.
In my own personal photography, I turn to the HDR method mostly during two times of the day, sunrise and sunset! I normally find myself shooting in the mountains and due to the nature of the low light and high mountains, I am normally battling with lots of shadows mixed with direct low light. In these situations, the dynamic range between the lows and the highs is far too great to capture with just one exposure. Getting multiple exposures is normally a great technique to capture all the information needed for me to portray the scene in Lightroom as I’ve seen it with my eyes.
You are not just limited to sunrise and sunset. Anytime you feel like the difference between the shadows and the highs is too great switch over to HDR mode and grab those extra exposures. It is also a great technique for interior and architecture photography.
If you have any questions drop them below and as always thanks for stopping by and happy shooting!