THE DYNAMIC RANGE OF THE SCENE AND HOW TO DEAL WITH IT

"I don't edit my photos in any way, I don't like artificial landscapes, I want the photo to be natural". I hear similar opinions from some landscapers quite often. However, this is a basic mistake. Why? We will explain this in the following lines.

You must have encountered when photographing, for example, sunrises/sunsets, that in your final photo the sky was overblown, while the bottom of the photo was drowned in darkness and completely devoid of drawing. The cause of such a photo is the dynamic range of the scene exceeding the capabilities of the camera. The dynamic range of the scene can also be understood as the contrast of the scene, or the difference between the lightest and darkest parts of the photo. Today's best cameras are capable of recording a dynamic range of up to about 14 EV (EV = exposure value, degree) under laboratory conditions. However, human eyesight can adapt to conditions as high as 30 EV! This means that at sunrise we will perceive our composition as beautifully rendered, while the camera will produce a completely different photograph. Let's discuss what are the possibilities of eliminating this mischief and how to achieve a photograph with a similar dynamic range as perceived by the photographer's eyes at that particular location.

GRDUATED ND FILTERS

The first option is to use graduated ND filters. Most of you have probably encountered these before. They come in screw-in/retractable versions, with soft or hard transitions and different intensities of darkening part of the scene. Neutral Density graduated filters are produced as split filters, one part of which is completely clear and the other neutral grey. With these transition filters, we eliminate excessive dynamic range in the scene by rotating the darker part of the filter to the bright part of the composition. So in most cases, we darken the top of the photo (the sky) and the bottom remains just as bright. This will balance the dynamic range between the top and bottom of the photo.

The use of graduated ND filters is very common among landscape photographers, but I don't use those filters as a matter of principle. There are several reasons for this:

Scenes with the sun are very susceptible to flares. The more glass we layer on top of each other, the more we increase the risk of flares, and the more filters we use, the more often the sharpness is degraded.

Cheap filters in particular often suffer from colour shifting of the scene into unwanted colour tones (often purple).

Acquiring graduated ND filters is not a cheap affair. If we want to avoid at least some of the above negatives, then we are probably left with only one brand, namely Lee filters. Their quality is legendary, unfortunately so is the price. Nowadays you can pay for sets of Lee soft and hard 0,3, 0,6 and 0,9 transition filters relatively high price. Not to mention the fact that waiting times for Lee filters nowadays normally reach more than half a year.

Like other optics, filters require unprecedented maintenance. A scratch on a filter from careless handling often results in the forced purchase of a new filter.

Handling filters in the field is somewhat tedious, making it easy to miss unique lighting conditions.

Filters have a linear transition, which is a problem in compositions with a rugged horizon. This can make the effect of graduated ND filters easily visible in a photograph.

The dynamic range of a scene can be higher than the sum of the EV compensation of all our filters. In challenging lighting conditions, the exposure difference can be really huge and then even a series of 0.3, 0.6 and 0.9 will not be enough. I have already mentioned above about multiplying the number of additional glasses in front of the lens and possible negatives.

EXPOSURE BRACKETING

The method of exposure bracketing is nothing new in landscape photography. It was used in a specific way by landscape photographers with classic cameras decades ago. With the rise of digital cameras, the use of exposure bracketing has become much simpler. This technique is essentially simple. We simply take one photo multiple times. One photo will be dark, one will be medium (we can call it neutral) and one will be light. We then blend these three exposures in some photography editor. We'll take the sky from the dark exposure, the dark to black parts from the light exposure, and the rest from the neutral exposure. That's basically it. Simple, right?

Why are we doing this? As we've said, the human eye is almost perfect. It can perceive vast differences between lights and shadows. Our camera chips are much worse. Exposure bracketing increases the dynamic range of the chip. And it brings the resulting photography closer to what we saw with our eyes.

So we're trying to get more dynamic range (HDR). But beware. Unlike other methods that fall under HDR, we're only concerned with highlights and shadows with exposure bracketing. That is, the tonal parts of the photo. Exposure bracketing is not about colour. We adjust these to our liking when we finalize the photo in Photoshop, Lightroom, etc.

One more time. We are doing exposure bracketing to achieve the sky that is not overexposed and the shadows that are not just 100% black. So mainly because of the sky, we're going to take a dark photo. The middle photo will be used for most of the final photo. And the light photo, or the parts of it, we'll use for the shadows. That way we'll have at least some texture in them. To be clear - the shadow must be a shadow, so it must be dark. But we have to see something in it. If the shadow is just a black area with no texture, it has nothing to do in the photography.

Panorama compiled from total of 102 frames (3-level exposure bracketing of 34 frames in two rows, 2-level focus bracketing).

ADVANTAGES OF EXPOSURE BRACKETING

1. We don't have to spend money on graduated ND filters. For exposure bracketing we just need to turn on this function in our camera.

2. We don't degrade the quality of the photo by multiplying the glass in front of the lens and we reduce the possibility of unwanted flare.

3. We are not at risk of colour shifts in the scene.

4. Using the exposure bracketing method in the field is easy and does not require longer preparation and manipulation as in the case of filters.

5. We don't mind the ruggedness of the horizon. We can accurately overlay differently exposed photos even in the case of a very rugged horizon.

6. We are not limited by the number of filters. We can easily set the exposure differences of the photos on the camera according to the scene.

7. If we are shooting one-row or multi-row panoramas, then using exposure bracketing is the only way to deal with a dynamically challenging scene. This is because with this type of photography, the speed and precision with which we capture the images in all rows (especially sunrises/sunsets) is extremely important. If we are slow, the lighting conditions will change in a short while so that we will not be able to compose the resulting panorama. 

The following panorama is compiled from total of 27 frames (3-level exposure bracketing of 9 frames in two rows). Due to the angle of light and the scenery, the use of graduated ND filters would be almost completely impossible.