HDR is a well-known technique in Photography. The term started making its way to the general public recently, thanks to it being widely adopted in the smartphone market. But what is HDR, exactly?
Regardless of your photography skill level, knowing what HDR is and how it’s properly done will help you produce stunning images under harsh lighting situations. Let’s tell you all about it!
What is dynamic range?
Before learning about HDR, you should take some time to understand what dynamic range is. The Oxford Dictionary defines dynamic range as “the ratio of the largest to the smallest intensity of sound that can be reliably transmitted or reproduced by a particular sound system.” That definition refers to audio, but the idea is similar in photography. Dynamic range relates to how much data a camera can capture at the extremes of exposure in a scene, from the darkest to the lightest parts of a photo.
What is HDR?
HDR stands for “high dynamic range”. It is a technique used by photographers to balance light levels in a scene. It is commonly used in situations in which there are significant differences of exposure within a single frame. A common example of such situations is when indoors, shooting through a window to an area with direct sunlight. In this case, a camera will either under-expose the room or over-expose the outside.
We will talk about the technique later in the post, but the gist of it is that a photographer needs to take multiple shots at different exposure levels. Some need to be darker, so that the highlights are brought down, while some shots need to be brighter to bring out detail in the dark. These images are then merged together with specialized software, which will get all possible detail and put it together in a single image with a more balanced exposure across the spectrum.
HDR in smartphones
You have probably seen HDR mode on your smartphone. Turn it on when you want to capture more detail in the shadows and highlights. I would also recommend you learn the fundamentals of HDR photography. While a phone’s HDR mode improves images greatly, machine hasn’t beaten man when it comes to producing a quality HDR photo.
Machine hasn't beaten man when it comes to producing a quality HDR photo.
HDR photos are made by merging multiple images taken at different exposure levels. Some phones have been known to cheat the process by shooting one image, duplicating it, editing exposure, and then merging different versions of the same photo. This essentially works, but over-editing an image can bring out noise and other unwanted elements.
Other phones take advantage of multiple cameras to take the same photo in multiple exposure levels. This is considered true HDR, but somehow the software has a hard time getting highlights and shadows quite right.
Manufacturers set up their cameras and algorithms differently, so we can’t pinpoint the issue, but so far no phone has convinced us with their automatic implementation of HDR. Here is a sample of the difference between automatic HDR and true HDR. All were shot using the same phone (Moto E5 Plus) for a post in which we showcase what a professional photographer can do with a cheap smartphone camera.
How to make an HDR photo
Those who want to take things to the next level should learn how to make HDR photos manually. This will give you more freedom to capture the details you want and customize the image to your liking. The end product will always be better than automatic HDR.
What do I need to make an HDR photo?
- A camera/smartphone with manual mode.
- Know how to shoot in manual mode.
- A tripod. Camera needs to be static.
- A non-moving subject. (Some people experiment with moving people, vehicles, water, etc. You can get into that as you become more advanced in HDR photography.)
Shooting your images:
- Pick your scene, set up the tripod/camera, compose the image. Keep the camera still for the whole duration of the shoot.
- Lock your focus where you want it. You don’t want images with different focus points.
- Find the right exposure settings for your main subject. If there isn’t a single subject, or it’s too large, just balance exposure as much as you can.
- You will change nothing but shutter speed from now on.
- Take the first image.
- Change the shutter speed to make the image darker than the first image by one f stop (learn more about stops here) and take another photo.
- Repeat step six until the brightest point in the image is exposed correctly.
- Change the shutter speed to make the image brighter than the first image by one f stop and take another photo.
- Repeat step eight until the darkest point in the image is exposed correctly.
You may be wondering why I am not giving you a specific number of photos to shoot, which is something you see in most HDR tutorials. Many claim to have some magic number of pictures you need to shoot, but the truth is HDR photography doesn’t work that way.
How many photos you need to shoot highly depends on your scene, your equipment, the subject, light evaluation skills, and editing style. Depending on the situation, you can skip multiple f stops between exposures, but those are lessons for another day. Today we give you a general guide to capture all detail across the spectrum; from the darkest to the brightest points in your photo, as well as everything in between.
Merging your photos:
You will need to find software that can merge bracketed photos into a single HDR image. Some popular ones include Lightroom and Photoshop. More advanced users can get programs like Aurora HDR and Photomatix Pro 6. There aren’t many free alternatives out there, but a good one is Luminance HDR.
The steps for how to merge a photo are a little different with each program, so we can’t give you step-by-step directions. The idea should be across the board, though. Pick your images, tell the software to merge them, and edit to personalize the image.