This article is dedicated to high dynamic range photography, or HDR photography. This is a powerful and useful technique to maximise the dynamic range you can capture when photographing a highly contrasted scene.
As a photographer, the only place where you have full control over the light is in your studio. Everywhere else, you have to work with the kind of light you find.
Natural light is tricky to master. Landscape photographers soon learn that the best light to work with is there during certain times of the day (the so called blue and golden hours) and with certain weather conditions.
With light comes contrast. The difference in contrast between the deepest shadow and the brightest highlight defines the so called dynamic range.
A Typical Scenario For HDR Photography
It is late afternoon and finally the sunset you are after begins and the sky is a majestic display of red, yellow, orange and blue colours. Clouds light up with warm colours. The city below is lighting up.
Because sunsets don’t last long, you got in position earlier and with the camera now set up and the remote shutter release in your hand you wait for the right moment and… click!
Most often than not, what comes next is a disappointment. Your photo looks nothing like the scene you witnessed with your eyes.
Depending on how you set your exposure (manual or auto), you can find that:
- the sky is very bright and the foreground quite dark with little details;
- your foreground is perfectly exposed, but your sky is completely washed out;
- the sky is perfect but the foreground is solid black.
In the image above, it is clear the whole dynamic range cannot be captured in one single photo. Ligthroom highlight warning shows up in the sky, showing areas that are almost clipped to pure white (thus no details in there to recover). And the histogram shows there are almost no middle tones.
HDR photography will solve the problem.
The Bad HDR Photography Reputation
But one problem with HDR photography is that it has acquired a bad reputation.
HDR was particularly popular among photographers some years ago. Unfortunately, with the diffusion of automated tools to process HDR images, the internet was flooded with surreal, fake, overcooked, oversaturated and/or gritty HDR sunsets.
The problem is that it is easy to over process HDR images and many presets available in automated HDR software produce surreal and overcooked images.
In time, those images became synonymous of HDR photography, but HDR photography is NOT a style. It’s a technical tool. The goal of HDR is to expand the dynamic range of your images.
Good HDR photography is subtle and keeps the natural, yet richer, look of your images.
Furthermore, you don’t need to remove any contrast just because you can. Contrast is what keeps things natural.
The way you then manipulate the image has little to do with HDR photography. You can opt for realistic editing or you can go wild.
Understanding Natural Light And Dynamic Range
As a rule of thumb, a soft and diffused light, like during overcast days, will reduce the contrast in the scene.
The cloudy sky, in fact, acts as a giant softbox by diffusing sunlight and scattering it all around. As a result, the contrast between shadows and highlights, and therefore the dynamic range, is reduced.
On a sunny day with clear sky, the light is hard and very directional, casting deep black shadows while objects in full sunlight are extremely bright. This highly contrasted scene has a great dynamic range.
At sunset, the foreground is much darker than the sky and you cannot exposed correctly for both. Such sceneries can have extreme dynamic range.
In short, if you are not photographing in a studio, you will be often confronted with scene that are highly contrasted that benefit from HDR photography.
Camera Sensors and Dynamic Range
Camera sensors are electronic devices that react to light by converting it into an electrical signal. Sensors have a minimum and maximum light sensitivity. Too little light and the sensor will see nothing, too much and it will be blinded.
Modern sensors are, on paper, capable of dealing with dynamic ranges of 12 stops or more.
As a reminder, a stop is a measure of the change in the amount of light available. Every time the amount of light hitting the sensor is doubled, you gain a stop. Every time the light hitting the sensor is halved, you loose one.
How to Shoot for HDR Photography
Shooting for HDR is not difficult. Given that it’s better to be safe than sorry, I suggest you shoot for HDR when presented with a highly contrasted scene. You can always decide later what to do with your images.
Estimate the Dynamic Range
Can you capture all the details in the scene in a single photo?
To know that, you can use your camera light meter (in spot meter mode) to get a measure of the brightness of different parts of the scene. This way, you have an idea of the dynamic range you need to capture.
You can use also your mobile with a light meter app such as the iOS Light Meter app.
In the image above I sampled this morning view from my living room using my mobile, from the darkest area to the brightest one.
To expose the street in the deep shadow (photo 1), I need a shutter speed of 1/200th of a second. For less deep shadows (photo 2), 1/800th of a second is enough.
This means those lighter shadows are 2 full stops brighter that the darker ones.
The sky (Photo 3) is correctly exposed at 1/5000th of a second. The sky, thus, is almost 5 stops (or EV) brighter than the deepest shadows. This is, more or less, the dynamic range of the image.
Single Image vs HDR
Modern sensors can cope with 12-stops dynamic ranges or more. You should be able to capture the whole 5EV dynamic range, right? Unfortunately not. At least if you want some good image quality.
Let’s consider a single exposure and let’s say this exposure has value 0 EV. Next, let’s create an HDR version by combining three exposures taken at -2EV, 0EV and +2 EV.
After editing them with the same settings in Lightroom, let’s compare them in the image below.
At first, the two images are very similar, but the HDR photography one is a bit less contrasted. It has more detail in the shadows and the colours are more vibrant and saturated.
You could say you just need to brighten up a little bit more the shadows in the single exposure, reduce the contrast, increase saturation and you will get the same results as the HDR photography one, but this is not true. Let’s see a 100% crop of the two images:
As you can see the HDR photography (bottom) is cleaner and more detailed. Lifting the shadows more in the single exposure will degrade the image even more.
Even with the relatively modest 5EV dynamic range of my morning view, a single exposure will have a far worse image quality than that obtained combining multiple exposure into a single HDR image. Here’s a more technical explanation why this happens.
When in doubt, shoot for HDR photography!
Capture a Series of Differently Exposed Images
While HDR can be done on a single file, it is best to rely on multiple exposures.
Your sequence should cover a great dynamic range: again, better safe than sorry. Better to take a few extra images than realise later that you needed more.
Also, you do not need to collect the same number of underexposed and overexposed images. It depends on the scene you want to photograph. For sunsets, it may be better to use more underexposed images. This will capture all the details in the bright sky.
Pro Tip: Before starting a new sequence, take a photo with your hand visible in the photo. This will help you easily recognise the different sequences later.
As you will be combining different HDR photography images together, you should have as little movement as possible between the frames.
Set up your camera on a tripod and use a remote shutter to avoid camera shake. Most software will allow you to combine images taken handheld by performing an image alignment.
Handheld HDR photography is possible only when your slowest shutter speed is still reasonably fast. Otherwise, you’ll end up with blurred images.
It is also best to photograph a still scene, without fast moving clouds, people or traffic. A certain degree of movement among the different exposures is OK. You can correct it with a deghosting procedure, available in any HDR software.
In the image above, while recording my sequence, the clouds moved, creating artefacts in the sky (top image). I then removed this by deghosting (bottom).
Camera Settings for HDR Photography
Some phone and compact cameras have a built in HDR photography mode. You can use that but usually this works only if you save the images in jpeg format. Plus, you have little to no control over the whole process.
Here’s a short checklist for HDR photography camera settings:
- Set your camera to save the photo in RAW format and to manual mode;
- Use the lowest ISO setting working for your situation, as increasing the ISO will reduce the dynamic range the sensor can record;
- Keep the same aperture for all the photos, as this will affect your depth of field;
- Note the suggested shutter speed for the 0EV exposure;
- Set the shutter speed accordingly to the most underexposed image you need (e.g. -4EV).
- Change the shutter speed in steps of 1EV (double the shutter speed) after each photo of the sequence until you get the brightest image you need.
Some cameras have automated bracketing functions. These are great if you want to limit yourself to the +/-2EV range in 3 to 5 photos depending from the settings and the camera.
I started this article talking about how useful HDR photography is to capture compelling sunsets.
HDR photography is not only useful for sunsets though. It’s a technique you can use with any highly contrasted scene.
Indoor photography is not as simple as it sounds. If you are not shooting indoor professionally, you have to deal with the available light.
Natural light from windows with brighter outside view and uneven illumination inside calls for HDR photography.
Nightscapes in the city also benefit from HDR treatment, as there are many dark areas and bright lights.
In the image below, it was not possible to get both the details of the garden with its different coloured lights and the interior of the building with one single image.
Instead I took 8 different exposures and combined them in a single HDR image. Note that due to the long exposures needed to extract details in the darker part of the scene, I could not fully deghost the cloud movement. They moved too far during the recording of the sequence.
Even far from the city, HDR is useful at night. In the image below I could not expose for the clouds in the sky with the last colours of the sunset and for the road in the foreground and the lights on the dam.
Landscape photography is not only blue and golden hours, sunsets or foamy waterfalls and streams. It’s also weather photography.
A dramatic sky goes a long way in adding interest to your landscape. But bad weather usually means dramatic contrasts within the sky and between the sky and the foreground.
HDR photography allows you to fully exploit this great dynamic range.
Even if done in studio, HDR can be useful also with still life, to ensure maximum details and crispy, vibrant colours.
HDR Photography And Filters
Landscape photographers like to get things “right” in camera and their trick is called Graduated Neutral Density filter, or GND.
As I mention in this article about filters, GNDs are square filters mounted on a holder. This allows you to rotate them with respect to the camera body and to slide them up or down in the holder.
Those filters have a dark part and a clear part, with a transition in the middle. Their use is simple: place the darker part on the brighter area of your view (usually the sky), leave the clear part on the darker foreground and place the transition around the horizon.
The filters come in different strengths and their job is to balance the exposure across the frame so that you can capture all the dynamic range in one photo.
The filters work nicely, but are mostly useful for landscapes with a flat horizon, like seascapes or distant cityscapes. There are many situations, like interior and architecture photography, for example, where they are not as useful as HDR photography techniques.
Oh, and a good set of filters is much more expensive than any good HDR software.
HDR Photography Software
Before concluding this article, here’s a useful list of software you can use for HDR photography.
Adobe Lightroom and Photoshop
Lightroom and Photoshop have a Photo Merge mode that allows you to combine different photos into a single HDR image.
You won’t have a great deal of options to tweak the HDR. You can auto align the images (useful for handheld sequences), apply auto settings to the final exposure and choose from different strengths for the deghost, and preview these.
Photomatix is the big guy in the HDR world. You can move your image from Lightroom and reimport automatically the HDR image.
It has many options and presets and you can chose different methods to create the HDR (detail enhancer, tone compression, tone balancer, etc.). Every one of these method will create a different, basic HDR image that can be tweaked in many ways.
Photomatix Pro comes with a plugin for Lightroom called “merge 32 bit”. This will create a basic 32-bit HDR image you can edit directly in Lightroom.
Phone Apps For HDR Photography
HDR does not have to produce gritty, surreal and overcooked images. It’s a legit and powerful photographic technique that can come in handy in many different scenarios, to help you photograph your subject in all of its glory.
You can also check out our articles on avoiding HDR mistakes or capturing great HDR sunsets!