HDR and Photography
Unfortunately, we live in a world of acronyms and no matter what industry we work in, they are there, and in the industry I work in, there are truly millions of them including ‘HDR’. Maybe it is a method to help remember what the subject of the acronym is or maybe it is a convoluted way of the ‘super clever’ holding on to the illusion of ‘super cleverness’. Who knows, but if you are like me, I feel the need to actually know what the letters stand for and if they apply.
Bring in ‘HDR’. Without knowing what it is, or what it does, most of our smartphones have this capability and we refer to it as ‘taking a nicer photo‘. So let us dive into what HDR is and how we can use it.
When I take a photo, the camera looks at the shot, takes an educated guess at setting the exposure (lightness/darkness), and takes one single photo. We look at the photo and typically we will see bright areas and dark areas. For example, a landscape with a really bright sky or dull ground.
SO imagine if I could take say, three photos with different exposures. The first really dark, so the sky looks blue and clouds look white without being overexposed. The second, the balanced one, plain and no punchy colours, and the third, overexposed to bring out the mansion walls, green in the grass and the brown on the trees. The third one would give us an overexposed sky.
So in order:
- First: Underexposed, to get the sky colour and clouds.
- Second: Camera balances the exposure.
- Third: Overexposed, Sky is too bright and looks bad but, the foreground, grass trees have their colours brought out.
Now I have three photos: underexposed <> Balanced <> overexposed
Obviously, these photos are no good as separate photos, but what if we could put them together into one photo, knock out the over and underexposed areas and have a nice full of colour photo with a cloudy sky, the colours on the trees and grass and the building facing me looking bright and alive.
Well, this is what smartphones do, take multiple shots at different exposures then combine them together. This is called ‘HDR’.
HDR stands for, High dynamic range. The range kind of being from dark to light.
The DSLR cameras, it is a little different. If the camera doesn’t have an HDR setting then a slightly different approach is needed. We still need those shots in different exposures so let us consider how to do this.
DSLR and HDR, an experiment
- A Tripod. Absolutely essential. You want multiple shots of exactly the same thing, no movement of the camera.
- Set the camera to ‘Aperture Priority’. Set the aperture to f11.
- Set the camera to fire after 2 seconds. You do not want your finger to move the camera when you take a photo.
- Exposure Bracketing. There is a little-dashed line in the big viewfinder, a ‘0’ being the center. This is the master exposure on the camera. This can be mover up and down. On a canon typically, you hold the ‘AV’ down while rotating the wheel on top of the camera to alter this. This is the key to HDR. Set this to ‘0’.
- Take the first photo, do not move the camera then set the exposure to maybe -2. Take another picture then repeat for +2.
You should now have three photos of varying exposures.
- Download a copy of Lightroom, install the trial.
- Copy the three photos onto your computer.
- Open Lightroom and import the three photos.
- Select the three photos in the library.
- Goto: Photo > Photo Merge > HDR
- Play with the settings here and see the outcome.
Quite simply, take three photos of different exposures and merge them together.
HDR is another tool in our photographic toolbox that definitely has a place. The effort in getting the camera setup, stable and taking those shots is worth it when a program like Adobe Lightroom composes the final HDR image. Like all other components of photography, take your time and practice.