Is the photo so dark that you can’t see the model? Or is the whole frame so overexposed, as if you photographed a white sheet of paper? All this means that you have the wrong exposure.
Exposure in photography is the result of how much light hits the camera’s sensor or film in a given amount of time. If there was little light, then the picture will be too dark — underexposed, and if there is too much, then the scene will be overexposed, that is, overexposed.
We understand what exposure is, and find out how to set it up and measure it, as well as what parameters in the camera settings affect it.
How to set the exposure in the camera in manual mode
In manual mode (M for Manual), the photographer himself adjusts the basic camera settings. Exposure is affected by three main parameters:
In the era of film photography, exposure was adjusted using exposure coupler — a combination of aperture and shutter speed settings. There you can not influence the ISO — this is a constant value that depends on the parameters of the film.
A parameter that determines how much light will hit the matrix. The amount of light is regulated by the degree of opening of the so-called aperture blades. Denoted by the letter f and a number. For example, f/1.8, f/5.6. The smaller this number, the wider the aperture is opened and the brighter the photo will be.
Aperture also affects the sharpness and depth of field (DOF) — the zone in which objects are depicted clearly, without blur. The larger its number, the more areas of the image will be in sharpness. That is why the aperture is raised for group portraits (we wrote a guide for you on how to take a group portrait).
A small aperture increases the chance that the focus will miss, but it creates a beautiful blur in the background. The pattern of this blur is called bokeh. The shape of the bokeh depends on the design of the lens — the more aperture blades, the more rounded the bokeh pattern. You can give it any shape yourself (how to do this, read the text).
Controls how long light enters the camera. This happens due to the fact that the camera shutter remains open, allowing the photosensitive element (matrix, film) to collect light.
The shutter speed is displayed using a fractional number (for example, 1/125, 1/1000) or a “ symbol for seconds (for example, 5“ is 5 seconds). The lower the number, the darker the frame will be. The more, the brighter.
If the shutter speed is long and the camera shutter is open for a long time, then any movement of the hands in the picture will be displayed as a blur, fuzziness, the so-called “stirring”. The fix is simple — fix the camera still with a tripod and don’t move it until the shutter closes.
Also, slow shutter speeds are used for creative shooting — they create the effect of movement or a trail behind an object, draw with light. In addition, a slow shutter speed is indispensable for night shooting, when the camera needs to collect light for a long time in order to produce a picture.
Shows the sensitivity of the matrix to light. In digital cameras, this function can be influenced, but in the pre-digital era, ISO remained unchanged and depended on the speed of the film. Displayed as an integer — 100, 640, 800, etc. The larger the number, the brighter the frame.
Too high an ISO value can reduce the quality of the photo — noise appears on it. At too high an ISO value, there is so much noise that the picture “crumbles”. Therefore, there is the concept of “working ISO” — the limiting value of ISO, at which noise does not interfere. It depends on the capabilities of the camera (and, in general, its high cost), and can be either 800 or 6400.
By combining all three parameters, you can correctly expose the photo while maintaining maximum quality.
Bracketing, or in other words “fork”, allows you to take several identical shots with different settings. For example, three frames: medium brightness, darker and lighter. The same can be done with white balance to get an average shot, colder and warmer.
Why do you need exposure bracketing?
- Get three frames with different brightness if you are not sure about the exposure settings. As a result, there will be several pictures to choose from, from which you can select the best one.
- Get several frames in order to combine them later in a graphic editor. This is convenient if there are areas with strong brightness differences in one scene. For example, when shooting landscapes. So, in one shot, beautiful clouds will be visible in the sky, but the lower part of the frame will go into a deep shadow, while in another frame the sky will be completely white and textureless, but the grass will be saturated and detailed. By combining these two shots, you get a perfectly exposed photo. This is how you expand the dynamic range of the image. This effect is called HDR.
How to enable exposure bracketing
- Access the menu or look for the Exposure Compensation/AEB function on the camera display.
- Use the wheel to set the exposure spread. This is how the frames will differ in brightness from each other. Click OK.
If you are shooting with Nikon, then hold down the BKT button on the camera (not all models have it) and set the exposure step using the parameter adjustment wheel.
- Take three identical frames. The easiest way to do this is in continuous shooting. For more stability, you can mount the camera on a tripod.
How to adjust exposure in automatic camera modes
If you are a beginner who is intimidated by the manual mode, do not be discouraged. In automatic and semi-automatic modes, it is possible to adjust the exposure to achieve the optimal result. These are modes Tv or S (shutter priority), Av or A (aperture priority) and P (program).
As a rule, the camera itself determines well how to set the settings for optimal exposure. To do this, it measures the brightness of the scene, taking the mid-gray areas as a reference. It is believed that such areas reflect about ⅕ of the light that hits it, which is equal to the reflectance of 18% (this information will be needed when talking about gray maps for adjusting the exposure).
For more accurate metering and automatic exposure compensation, the camera can have up to several special modes. Consider how they differ and in what situation which one is better to use.
Evaluates the entire frame, taking into account the brightness of all parts of the picture. It is rare in modern cameras.
Evaluative (Canon) or matrix (Nikon) metering
It is also sometimes referred to as matrix or multi-zone metering. The frame is divided into several zones. In each of them, the camera measures the exposure and adjusts the brightness based on the received data.
Center-weighted or center-weighted average metering
Reads data from the entire scene at once, but the main focus is on the center of the frame. This is logical, because, according to the idea, the main object of the scene is often placed in the center. A detailed analysis of the entire scene, as in the case of evaluative metering, does not occur. This allows you to use exposure compensation as well (more on that below), as the camera doesn’t make automatic adjustments. Suitable for reportage and portrait shooting.
The brightness of only a small area of the frame is measured, and all other areas are ignored. This is usually the center of the frame, although many camera manufacturers allow the user to move the exposure metering point to another area of the frame. Useful if you are shooting a subject that contrasts with the background. For example, a white object on a black background or vice versa. It also performs well in studio shooting with backlight.
A kind of dot mode. Also covers a small point in the frame, but larger than with spot metering. If spot metering captures about 5% of the frame, then partial metering captures about 15%. Suitable for portrait photography.
Problems with automatic exposure arise when there are a lot of too light or too dark objects in the frame. For example, when shooting in the snow, wedding portraits of a bride in a white dress or a groom in a black suit. In such cases, the camera thinks that these black and white areas are actually a sign that the scene is either too dark or too light. Then the exposure may not be set correctly. In such cases, you can use the exposure compensation function.
Exposure compensation or exposure compensation allows the photographer to manually force the camera to lighten or darken the frame. To make a picture brighter, you need a positive exposure compensation, and to make it darker, you need a negative exposure compensation.
How to turn on the exposure compensation mode
- Set the camera to one of the modes — P, Av (A), Tv (S).
- Select the setting on the display — Exposure Compensation/Exposure Bracketing Set.
- Move the label. A negative value will make the image darker, while a positive value will make it brighter.
By default, the exposure compensation in the camera is adjusted with a certain step. A step is a twofold increase or decrease in the amount of light that enters the matrix or film. For example, for Canon cameras, this is ⅓ steps (that is, ⅓ of a step). This is how much lighter or darker the photo will be after the adjustment is applied. In the camera menu, you can independently set this step, that is, the difference between each new selected number.
Gray Card Exposure Adjustment
The gray card helps to fine-tune the exposure, as well as correct the white balance (details on what it is and how to change it can be found in this text).
- Place the gray card in the scene. The more space it takes, the better. This will avoid mistakes.
- Set the camera to spot metering mode. This is necessary so that the camera measures the brightness of a separate area, and not the entire scene.
- Take a measurement on the gray map.
- Lock exposure. Cameras from different manufacturers may have different names for this button or function. For example, Fujifilm has an AEL / AFL button, Nikon has an A AE‑L / AF‑L button, Canon has an AE button, Sony has AEL.
This is especially useful when there is a lot of black or white in the frame, when the camera may mistake these colors for gray in too dark or too light scenes.