Photographic Exhibition: Detailed Guide (Examples Included)

Mastery of light is what will define you as a photographer and correct measurement and photographic exposure will make you a master. For this reason, today we update this article with this topic that seems so important to us and that we are going to improve for you according to the questions that you ask us the most in the forum and by email. But before continuing, I would like to recommend our guide on lighting in photography with all the information and advice you may need, so that you can delve into the subject whenever you want.

If the light in the scene is not correctly measured, the photographic exposure will not be correct and therefore the quality of the photograph will be affected, making all the techniques and tricks that you have applied have been in vain.

Before learning how to measure light correctly, you will see why it is so important to do so: make a correct exposure.

In today’s article I will try to shed light on some topics that usually scare most photographers who are just starting out in the wonderful world of photography, but which they cannot fail to know if what they want is to achieve excellent photographs.

Sit back, bring your camera closer and read on.


What is Dynamic Range?

Before seeing how the light of a scene is measured to achieve a correct exposure, it is necessary that you understand what is dynamic range and why it is so important when it comes to achieving a correct exposure:

The Dynamic range measures the amount of light and dark tones that your camera is capable of capturing in the same photograph, that is, it is the ability of the camera to obtain details in both areas of a photograph, the lights and the shadows. Dynamic range sets the amount of tonal nuances your camera is capable of capturing.

Pay attention to the following photo. Two opposite situations coexist in it, a very light area and the other very dark. These types of situations are impossible to solve by digital cameras, so they will not be able to offer you detail in both areas at the same time because their dynamic range is not wide enough. You will have no choice but to go for detail in one area or the other: detail in the shadows and blown highlights or detail in the very dark highlights and shadows.

Dynamic range in photography

The greater the dynamic range of your camera, the more details it will be able to capture and therefore the better the quality of the final photographs. Of course, as long as you make a correct measurement and exposure of the scene to take advantage of its full potential. Don’t worry, keep reading and you will learn how to do it!

And if you are curious to know the dynamic range of your camera, you can see it on this website.

What is exposure in photography?

The exhibition in photography It is the process by which light reaches the photosensitive material, that is, the film or reel in analog photography, and the digital sensor when we talk about digital cameras.

Contrary to what it may seem to you, the exposure is not the time that the photograph is exposed to light: time is only one of the three variables that control the entry of light to the focal plane (sensor) to achieve a correct exposure.

What is the exposure triangle? 3 variables that influence exposure in photography

These three variables that I just mentioned are the ones that make up the triangle of light. Let’s see them in detail.

1. ISO sensitivity

ISO sensitivity determines the amount of light the sensor should capture. The lower this value is, the less light it will capture. The higher, the more light.

In analog photography to change the ISO sensitivity you have to change the film, but in digital cameras, we are lucky to be able to adjust it with a button.

What is noise in photography?

As I told you in the article “24 ways to get super sharp photos”, if you raise the ISO sensitivity too much, your photos will have more noise, less sharpness and therefore lower quality. Use high ISO values ​​only when you have no other alternative, that is, when you cannot achieve a correct exposure by compensating for the “lack of light” caused by using a low ISO through the other two variables that we are going to see now: decreasing the speed of shutter or opening the diaphragm.

two. diaphragm opening

The diaphragm is a device that is inside the lens of your camera and that allows you to control the amount of light that reaches the focal plane (sensor), along with the shutter speed, and at the same time, regulate the depth of field of the camera. photography, that is, what will come out in focus and what will not.

The more you close the diaphragm (higher f/ values, for example, f/16), the greater depth of field you will obtain in your photographs (more focused image planes), but the less light reaches the sensor, having to compensate for the lack of this either by increasing the ISO sensitivity or by decreasing the shutter speed.

The wider you open it (at lower f/numbers like f/1.8), the shallower the depth of field (more blur or bokeh) and more light will reach the sensor, allowing you to use lower ISO values ​​and faster shutter speeds.

3. Shutter speed

Shutter speed is the time the shutter stays open allowing light to reach the sensor. The faster the shutter speed (1/1000s), the less light that reaches the sensor and the slower the speed (1”), the more light that gets through the shutter. In this video Mario explains it very well:

By adjusting the shutter speed you will not only achieve lighter or darker photographs, but you will also be able to convey the sensation of movement using very slow speeds or using very fast speeds, you will be able to completely freeze a scene.

landscape during sunset

As a summary, in this graph you can see what each of these parameters affects with their main and secondary effects:

How do you get a proper photographic exposure?

An excellent tool that will help you make a correct exposure of your photography is called “reciprocity law” which is nothing more or less than a rule with which you will obtain the same exposure (photo) with different combinations of speed, aperture and ISO sensitivity. No, don’t panic yet! Here I explain it:

Law of Reciprocity: the 3 variables to achieve a correct exposure do not have a unique combination, but you can adjust each of these differently and achieve exactly the same exposure.

Observe the following image: in it you will be able to see different combinations of diaphragm opening and shutter speed that will result in the same exposure, that is, the same photograph neither more nor less exposed, the same.

How to Balance Exposure Variables

A very simple way to get the same exposure with different combinations of ISO, shutter speed and aperture is to do “doubles and halves”. What does this mean? It’s very simple pay attention:

If you leave the aperture fixed, you can get the same exposure by changing both the ISO sensitivity and the shutter speed as follows:


The exposure in all cases will be the same: if you double the ISO sensitivity, to achieve the same exposure you can double the speed and still keep the same exposure in your photo.

The same thing happens if you set the ISO sensitivity and change the shutter speed and aperture:


In all combinations you will get, again, the same exposure. Note that this time the relationship between the two is inverse: when you close the diaphragm you will have to decrease the speed in order to compensate for the light entering the sensor.

The last relationship that remains to be seen is by fixing the shutter speed, obtaining the same exposure by modifying the ISO sensitivity and the aperture of the diaphragm, to obtain the same final photograph.


The law of reciprocity is extremely useful, with it you will be able to adjust the parameters of the shot to be taken in a more conscious and controlled way, making the most of the power of your camera.

Now let’s see the same scene taken with different parameters but with the same exposure (regardless of whether it is correct or not).

ISO 200, 1/100s, f/5 ISO 200, 1/160s, f/4 ISO 200, 1/250s, f/2.8

The key so that you can fully understand how it works is by taking your camera and doing the tests yourself with any object you have at hand. Take any of the examples I mentioned earlier and start taking photos.

When is a photograph correctly exposed?

A photograph is correctly exposed when the sensor is capable of capturing as much information (light) and tones (dynamic range) as its capacity allows. Imagine that you have a camera capable of taking photos in a resolution of 18 megapixels, but you only shoot in 8: you would be wasting the potential of your camera to work with better resolutions.

The same happens with light, if your camera is capable of capturing much more light than you, by adjusting the 3 exposure variables you allow, you will be wasting a lot of information that the sensor is capable of capturing, but that you are leaving out .

3 Exhibitions

The middle photograph is correctly exposed, it may not be the final result you want for it, but it was possible to take advantage of almost all of the sensor’s ability to record light, that is, its dynamic range was used to the maximum. Once you have achieved a correct exposure, you can edit* it on your computer without losing quality.

If you over or underexpose your photos, you will be sacrificing a lot of valuable information, which you will not be able to recover later through editing, so if once on the computer you want to “lighten” or “darken” the photos, you will reduce a lot of quality since the computer you will have to “invent” information where there is none.

*by editing I only mean adjusting certain parameters such as exposure, luminance and shadows on the computer, unlike retouching where the scene is directly modified by altering it.

Taking a picture in which the histogram is checked

Achieving correct exposure will be easier if you take advantage of the following tools that you have at your fingertips (in your camera):

exposure meter

It is in charge of measuring the “amount of light” necessary for a photograph to be exposed correctly. Once it receives the light reflected by all the elements of the scene, it calculates a value…