What is HDR? An HDR Definition
High Dynamic Range (HDR) photography produces an image with a broader range of tonal detail than would normally be produced by a single image from your average camera. In this video tutorial and accompanying article, we are going to discuss exactly what is HDR and what types of scenes have a high dynamic range to begin with. Watch this entire article in video format, or read the written article below.
Full HDR Video Tutorials
The following is an excerpt from our HDR Tutorial by SLR Lounge. This workshop dubbed “the gold standard of HDR education” by FStoppers contains over 13 hours of tutorials, RAW files for you to follow along, and dozens of full prep to post examples. We cover bracketed HDR, in-camera HDR, single-shot faux HDR, single-shot bracketed HDR, panoramic HDR and more! Click here for more info.
>What is HDR? Video Tutorial
What is Dynamic Range?
Dynamic range simply refers to the range of light in a scene from the darkest shadows to the brightest highlights. A scene that has a high dynamic range simply means that there is an extremely broad range from the darkest shadow to the brightest highlight. The problem with cameras is that their dynamic range is fairly limited (at least when compared to our eyes). This means that if you are able to see detail in the shadows, then your highlights are typically completely white or “blown out.” Vice-versa, if you can see details in the highlights, generally the shadows become fully blackened or “clipped.” The goal of an HDR photograph is to capture more of this dynamic range than would not be possible with a single image.
Dynamic Range of the Human Eye
The human eye has an incredible dynamic range that is estimated to be around 20 stops. A stop is simply a measurement of light that will be further explained in a later article within this HDR series. The dynamic range of the human eye is significantly broader than most DSLR cameras with ranges between 10-14 stops.
For example, take a moment and look at the room around you. Most likely, you will see a room with bright highlights where you have lighting (be it a window or tungsten light) and you will also see dark shadows where the light isn’t falling. However, our eyes can generally see the entire dynamic range within a scene like this. Meaning, you can see details in the shadows and simultaneously see the detail in the highlights. Take a moment and walk outside, after your eyes adjust, you can once again see all the detail in the shadows and the highlights (even when looking in the direction of the sun).
However, in these same scenes, the average camera is only going to see a portion of that 20 stop range. For example, if your camera has a dynamic range of 10 stops, then the camera will see half of the range that your eyes would see. Let’s relate this to our examples. If you are inside, and you are trying to see the detail in the shadow areas of your room, your camera is going to reach a limit where everything brighter than that 10 stop range will be completely blown out. Likewise, stepping outside, if you wanted to capture the detail in the clouds and bright sky, the camera will not be able to show detail in the darker shadows that are below the horizon line.
I am sure you have all had the experience of trying to take a portrait of a friend standing in front of a beautiful sunset. Remember how that shot always turns out? Either your friend is nice and bright, an the sky behind him/her goes completely white, or the sky looks amazing and colorful and your friend is pitch black.
Let’s show you a real world examples shot from a Canon 5D Mark III. In this first image, we can see all of the detail in the clouds in the sky, but notice how everything below the horizon line that is in the shade is almost completely clipped.
In this second example, we have gone 4 stops brighter to show detail below the horizon, but now look at how most everything in the sky is blown.
This is the limitation of our camera’s dynamic range in comparison to our eyes. Again, the goal of HDR photography is to broaden that range by using several techniques (bracketing, single-shot HDR, etc) which we will be discussing in additional detail. But, to give you a little taste, here is an example of the final HDR shot that we created from this scene.
All Cameras Are Not Equal
DSLR Cameras that have a broader range are generally more expensive. Sensor technology is getting better and better which allows the latest cameras to have a higher dynamic range. More recently, Nikon is currently the leading brand when it comes to highest dynamic range with the Nikon D800 having a dynamic range of 14.4 EV (Stops), whereas the Canon EOS 5D Mark III has a range of 11.7 EV.
What is HDR | Conclusion
HDR photography has the potential to produce images that are closer to what we can see with the naked eye (or beyond if they are processed too far), with crisp detail visible in all ranges of light. Again, in this HDR series, we will discuss several techniques to broaden the dynamic range of your images.
For more HDR education, be sure to check out HDR Tutorial by SLR Lounge. This comprehensive “gold standard” guide will give you a mastery of HDR photography, from the scene considerations to the actual shooting to the post production. Click here for more info.
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