Surely more than once you have read something about the dynamic range. It usually appears here and there in any article about exposure, histogram, light meters or light in general. But do you really know what it is? Do you know how to get the most out of it? Well, I hope I know how to explain myself well and, by the end of the article, you are a master of dynamic range, or at least you have understood and internalized the concept 😉 And if you want to delve into lighting in photography, this is the article you were looking for.
What is dynamic range?
As we are always surrounded by photographic buzzwords that get tangled up in our fingers, cloud our minds and confuse us, this time, we will leave the definition for later.
Now just think: how many times are you looking at a beautiful scene, of which you like everything, with a magical light, beautiful colors, and you decide to take out your camera to immortalize that essence, that wonderful light, that sky full of infinite tones, frame , expose, shoot and surprise! Photography and scene have nothing to do with each other. You get the burned sky, without tonalities, or the dark earth, without textures. Nothing to do with the wonderful scene before you. Hasn’t it happened to you millions of times?
Well, that’s mainly due to two factors:
- That happens first, because our eye is infinitely better than a camera (no matter how professional it is) in capturing the simultaneous detail in lights and shadows, since it has the ability to continuously adapt the pupil to the different brightness levels of the scene.
- Secondly, because the scene (although as we are able to process it correctly at first glance, it may not have seemed so to us), it has too much difference between light and shadow so that the camera can correctly process both, that is, it has more dynamic range than our camera can capture.
DYNAMIC RANGE (or Dynamic Range): is the ability to capture detail in lights and shadows within the same image. That is, our ideal goal is get almost pure blacks and whites with lots of intermediate values.
The human versus the machine
When we talk about dynamic range, we talk about the ability to capture the different lights and shadows with detail in a scene, right? We usually express this difference in diaphragm steps. Many more steps of difference diaphragm is able to correctly express our camera, better dynamic range will have this. In other words, a camera that has a dynamic range of 8 diaphragm stops will be more capable of capturing the lighting reality of the scene than one that only has 5 diaphragm stops.
And while our cameras are working, for example, with 5-8 f-stops, our eye is capable of processing scenes with more than 15 f-stops difference. Almost nothing, right? That’s why we always, always have to assume that in scenes with a lot of difference between light and shadow (highly contrasted), our camera is going to be unable to portray what our eyes see.
The histogram, your great ally
We already talked about the benefits of the histogram, how it can help you see if your image is well exposed or not, but not only that, it can also help you see if your image has a rich or poor dynamic range, and therefore Therefore, it can help you work on the spot to improve it. Let’s see how the different types of dynamic range are translated depending on the scene and the histogram in various images:
Image 1:
What can we deduce from the following image by observing the histogram regarding its dynamic range? If you look closely at the histogram, you will see that it contains information throughout the histogram; in the central zone as well as in the extremes (left shadows, right highlights). This means that from this scene, we have managed to obtain a good dynamic range, since we have information on midtones, highlights and shadows.
Image 2:
What do you think of the next scene? Would you say it has a good dynamic range? If you look at how the information is distributed throughout the histogram, you will see that it contains, like the previous image, information in all the light areas, so we would also say that it has a good dynamic range.
Image 3:
Now look at the following image, would you say it has a good dynamic range? Most of the information is concentrated in the right part of the scene, corresponding to whites and highlights, but the left area hardly has any information, there are hardly any shadows or blacks, do you see?
Image 4:
Finally, look at the following image. What do you think of the dynamic range of the image? Have you noticed how the information of the lights is concentrated in the left area of the histogram? In this case, there is no information, only highlights or whites.
How to get the most out of dynamic range
Note, however, that if the scene in front of you does not have too great a difference between light and shadowthat is, if, for example, your camera supports up to 7 steps of light difference, and the scene only has 5, your camera will be perfectly capable of portraying what is in front of him. You can do the test by measuring the darkest areas of the scene and then the lightest and see how many stops of diaphragm difference there are between them to know if your camera will really be able to portray the scene faithfully.
But the essential thing when it comes to achieving the maximum dynamic range that it offers you is seize itand that is done simply making a correct measurement and exposure of your photographs. That is to say, there will be scenes that are, naturally, somewhat opaque, or with very high contrasts, which will leave a good part of the scene without light information. No need to worry, there are images that are just like that. Now, of any scene that we want to represent, the important thing is not to fail in the measurement and exposure of the image because if it is well exposed, it will mean that we have achieved the greatest possible dynamic range in situ and that we can then work on it in the processing to enlarge slightly more the dynamic range of the scene.
Of course, do not forget to shoot in RAW whenever you anticipate that you are going to retouch your images.
Techniques to increase dynamic range
Filters
There are landscapes so beautiful that it seems that they are going to have to be photographed alone, right? Too bad that when taking the photo the usual thing happens to us, that the sky has too much light compared to the ground and it turns out that it is burned, or the ground is too dark. Now we know that this is the fault of the limited dynamic range of our cameras ;-). Luckily we are not alone in the face of danger. With the help of a gradient neutral density filter, we can help offset the two exposures thus reducing the difference between lights and shadows, and helping to expand the dynamic range of the scene by not having to choose between lights or shadows.
bracketing
There are different types of bracketing (or bracketing), although in this case we will focus on the exposure. The Exposure Bracketing consists of taking several identical images in framing, only changing the exposure in each one of them. Normally three images are made, one exposed for the lights, one for the shadows and one with the “correct” values provided by the camera. Once we have the images with the different exposure values, we can join them using Photoshop or some other editing program so that all the information overlaps one on top of the other, giving us detail in all areas of the image. For a better explanation click here 😉
Work the RAW file
With our file in “raw” and the amount of information about lights and shadows it contains, recovering lights is simple and usually gives good results as long as we start from a good image. Work the basic settings such as shadows, highlights, blacks, whites and even contrast, will allow you to expand the dynamic range of your image in a satisfactory way.
If you doubt between exposing for the shadows or the lights, do it for the shadows, these are more difficult to recover than the lights, because doing so generates a lot of noise. is what we call right the histogramor what is the same, that the image tends more towards the highlights than towards the shadows, so that we can finally recover the image with less loss of quality than in the opposite case.
Definitely
In order to faithfully represent what surrounds us, so that an image is capable of transporting us to the scene that existed at the time of taking the shot, the closer we get to the original model, the more the viewer of our images will be able to delve into that moment. That is why we never recommend abusing retouching or HDR, too many retouching gives a feeling of unreality and distances us from the moment that we wanted to represent through our image.
I hope that this article has been useful to you, that it has given you something and, above all, that it has made you go find the camera, or open the computer to fiddle with and analyze images, histograms, lights and shadows. You only learn by tinkering and practicing 😉 Oh, and don’t forget to share if you think it might be useful to someone else. Thank you and see you soon.