Camera Basics #09 - Focus types of the camera
Focus: one of your camera's most important tools for getting a sharp and accurate image. However, there are different focus types or focus modes of your camera that work differently and are more suitable for certain subjects than others. In this post, you'll learn all about the different modes and how they work!
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What is focus anyway?
The focus in the camera determines how sharp an image appears in the final result. In simple terms, the viewfinder field corresponds to the area that will be in focus and where the focus will end up. It also depends on which metering field the camera or photographer has set, in which the focus point can move. The focus is defined directly with the sensor measuring field (usually centered), because in this way the photographer has the possibility with a half-pressed shutter release to define the focus area. The focus is closely related to the aperture setting, because the lower the aperture number, the smaller the plane of focus and the less is in focus in the image.
Where do you find the focus in the camera?
With modern equipment, the focus is usually set in the lens, where the plane of sharpness changes depending on the focal length. The focus in the camera is either automatic or manual. The automatic camera focus or also called autofocus is installed in the camera or in the lens (not in all). This is found in the camera on special setting buttons (usually called AF-S, AF-C). Not all lenses also have autofocus, which (if present) is also indicated by the abbreviations AF-S or AF-P. If these are activated, autofocus is active. If these are activated, the autofocus is switched on.
What are the focus modes?
Manual mode / Focus manually
For which area is this mode particularly suitable?
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Architectural photography
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Landscape photography
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Astrophotography
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Still life, like food photography
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Macro photography
In contrast to this, there is also the manual mode, which works like the "Manual" subject program, since here the photographer has to do the focusing himself. This is especially useful when shooting in difficult lighting conditions or when the autofocus does not focus properly. In this way, precise settings can be made and the focus can be fixed for a series of successive photos. What to use manual focus for:
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Low contrast situations
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In backlight situations
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In dark light situations when the contours are not clearly visible
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During fireworks
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In macro photography from a tripod
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With recurring patterns
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When there are many fine details
A motor built into the camera or lens is used to focus on a manually or automatically selected subject. Many photographers use autofocus because it is usually faster and more precise than manual focus. Autofocus is especially useful in sports and wildlife photography, where subjects move quickly and dynamically. Many camera manufacturers are constantly trying to improve autofocus, as it is a crucial factor for the speed and sharpness of a lens.
Autofocus: contrast and phase detection
For which areas are these modes especially suitable?
Phase detection:
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Sports photography
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Portrait photography
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Wildlife photography
Kontrasterkennung
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Landscape photography
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Astrophotography
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Still life
Autofocus is further divided into two main types on a technical level: Kontrast-und Phasenerkennung. Phase detection is very fast and particularly good at tracking moving objects, but also prone to errors such as alignment. Contrast detection, as the name implies, works with the light conditions of the image and is therefore more accurate. With this type, the camera must evaluate and process data from the sensor, making the type of focusing longer and more suitable for still subjects (such as landscapes).
In most DSLR cameras, phase detection is the most commonly used type of focusing, since it runs through the viewfinder. Contrast detection is done via the LC display (DSLM cameras usually have this type built in). Both types work with the "optimal focus plane" in the image (usually the intersection with the main subject). For moving objects, phase detection is faster, for still life, contrast detection.
Single and series servo autofocus
What are the two instruments particularly suitable for?
Single servo AF:
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Portrait photography
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Macro photography
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Detail photography
Kontinuierlicher AF
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Sports photography
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Wildlife photography
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Speed
The main instruments of autofocus, include focusing modes: continuous and single servo autofocus. Continuous Servo:
Continuous servo is also referred to as AI servo (Canon) and AF-C (Nikon). Essentially, this means that the camera continuously adjusts focus when you hold down the shutter button. This is ideal if you're shooting a moving subject and want to track its position. With the single servo, on the other hand, the camera focuses and does not correct the focus again until you release the focus button and try again. The servo is also known as One-Shot (Canon) and AF-S (Nikon). This is particularly suitable for stationary subjects.
Area modes of autofocus
Selecting the range mode tells the camera how to "follow" the subject. It is important here that the camera has many focus points in the selected area to best track and image the selected subject. It is easier to track a moving subject if the camera has multiple focus points that cover a large portion of the image. However, you still have to select how the focus points are to be used:
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single-point autofocus (a focus point selected by the photographer is used)
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Dynamic Autofocus (single focus point, but can move and track subjects in the focus point area)
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Face detection: The latest cameras feature face detection, which allows the photographer to focus precisely on faces (eyes left/right) â especially advantageous for portraits
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3D tracking autofocus (the camera follows the subject as it moves across the focus points)
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Group Area Autofocus (multiple autofocus points are used at the same time. same priority for all and focus on the closest subject located on one of the fuÌnf points
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Auto-area autofocus(in this case, the camera automatically scans the scene and decides on the subject (often the closest object to the camera or a face)
A little task for you:
Photograph one subject with autofocus and one in manual mode. Pay attention to how exposure and sharpness behave. Where do you have more influence on the focus area? In which mode do you get better results?
Show us your pictures on Instagram and/or Facebook and tag us @fotokochde! We look forward to seeing your results!
Thanks for reading this article. If you're interested in more photography basics, then check out the other camera basics
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You bought a camera and are taking your first steps in photography? With the automatic mode you miss a lot of potential! Photography is only really fun when you understand your camera and know exactly which settings you need to get the photo you want. Learn the meaning of the functions and ignite your enthusiasm for photography!
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