HDR -- What is it, and How to Use it
High Dynamic Range, or HDR is a term you’ll seen thrown around in newer 4k televisions, and even in video games. The practice first originated in digital photography. HDR can even be seen in newer camera phones now-adays, so what is it, and what’s with all the hype?
HDR, in terms of photography, is essentially a processing mode in digital cameras that allows you to produce a photo with a ‘dynamic’ range of settings including ISO, and saturation. By combining shots with multiple ISO/exposure settings, you can produce a combined image with multiple ranges, making it ‘dynamic.’
So why would you want a dynamic range in a photo?
HDR in photography really comes down to this: in some instances of a scene you want to capture, you have both dark and light areas of an image. Some where light is hitting a part of a scene very hard, and other parts where there’s hardly any light at all. To compensate for this, without HDR, you need to find a sweet spot in your exposure and ISO to find a light-balance where you produced a balanced image. On the other hand, if you used an HDR method, you can capture the scene at 3-5 (or more) various exposures, and combine them into a single image. This means that you no longer have to compromise in the appearance of a mixed-light/dark scene. You can lighten up the lower-light region as much as you want, and reduce the exposure of a bright area creating a more light-balanced photo.
Who uses HDR?
HDR is great for landscapes or indoor shots with varying light levels (think of photos with areas with lots of light, and with areas of low-light). Real-estate and architectural photography is a particular style where HDR is heavily relied upon. Think about it: you need to sell a house -- you need to make it look as good as possible to attract people to come take a look. One way to do this is to use HDR to your advantage for both indoor and outdoor shots. Indoors, HDR will add a range of light-texture to accentuate where the natural light is falling in the room. Natural light also changes throughout the day as the sun moves. HDR can help capture more of the natural light, and how it may look throughout the day to give potential clients a better idea of how the space will look throughout a given day.
What do I need to create an HDR image?
Most newer digital cameras will have an HDR setting included, however some do not. You actually don’t need HDR on your camera to create an image with high dynamic range. All the built-in HDR modes are doing is combining a set # of multiple shots with various exposure settings (that you can typically customize) together into one image. This is however something you can do manually inside a program such as Photoshop. By stacking your multiples of shots to various layers inside a .psd file, you can combine them by altering the opacity of each layer, while using the eraser tool with various opacities. Granted this method is harder, but it also allows for more complicated blending, which in some circumstances, can be essential.
Either way you do it, keep that camera stable!
To do this, the first thing to take into account is what you’re shooting. Since you need to combine what should be nearly identical shots at multiple exposures, static or ‘non-moving’ scenes such as landscapes or architectural shots work best. If something is moving in your frame between your shots, you’ll have an inconsistent set of images to work with which will make things complicated, and possibly unusable. This goes for the camera too! If the camera isn’t stable, and it’s not in the same position for each shot, you’re going to have a tremendously difficult time combing the shots (and the automatic HDR mode on you camera will have trouble too!) -- everything from blurred scenes, to completely unusable shots. Use a tripod to keep your camera in position. A remote, or app that allows you to adjust settings can help to keep things stable too (so you don’t have to touch the camera at all when taking shots). Think of it like a long exposure!
Below is an example of classic HDR photography:
In this woodland scene, you can see that despite this being dusk with minimal light levels, there’s a ton of definition in both the ground, the tree bark, and the water -- but notice, there aren’t many movement-artefacts in the water. You could absolutely capture something similar to this with a long exposure, but that could shift the focus on the water (capturing movement) and the sky would likely be blown out (or too bright) -- the balance would be nowhere as close.
What I also like about this image is that even though you’re shooting in HDR, the colours and exposures were balanced enough to the point where it doesn’t look too hazy or blow out. There is a tendency in automated HDR profiles (depending on the camera) to make a scene look almost as if it’s airbrushed, or the contrast has been increased. This is where manual HDR using Photoshop can be very important. For landscape photography, generally you want to capture things as they look in real-life, while not taking too much liberty to alter the colour of the scene. Now, that’s not true of all landscape shots, but for a simple beautiful scene like this at dusk, this is exactly the kind of balance in tone that can make a photo great.
-- article by: Alexander Tri.