The digital single-lens reflex camera is a high-tech tool capable of capturing professional-quality images, even for the novice. However, to control the outcome and produce the best photos requires an understanding of the camera's features and how to use them.
Most DSLR cameras offer automatic modes that let you snap acceptable photos with little effort, like those taken with a smartphone. However, photographers achieve the best results using camera features that allow complete control over the process. These settings may seem daunting at first, but with some practice, they become second nature and offer an opportunity to create unique, high-quality artistic images.
Digital photography is much more fun when you are familiar with your DSLR camera and know how to use it to get the desired results.
Shop this article: Nikon D7500, Nikon D850 and Canon EOS 90D
A DSLR camera such as the Nikon D7500 contains an internal mirror and prism mechanism that reflects light from the lens to the optical viewfinder or LCD screen, letting you compose an image.
When you press the shutter-release button, the reflex mirror swings up out of the way and the shutter opens. The light collected and focused by the lens is captured on a digital image sensor.
The camera's processor converts the information from the image sensor into a Raw or JPEG format, then writes it into a memory card. The entire process occurs quickly — some professional DSLR cameras can do it more than 11 times per second.
Preparing your camera before taking photos begins with selecting a shooting mode. These are usually found on a dial labeled with "Auto, Av, Tv, P, M" and more. Between the fully automatic mode — which lets the camera's microcontroller control all settings — and manual mode (M), the semiautomatic modes include Aperture priority (A or Av), Shutter priority (Tv) and Program (P).
Aperture priority is a semiautomatic mode that lets you control the aperture size while the camera automatically selects the best shutter speed to achieve the proper exposure.
Aperture is measured in "f-stops" (f/2.0, f/2.8, f/4.0, f/5.6, f/8.0 and higher), which represent a ratio of focal length over the diameter of the opening. Higher numbers indicate a decrease in the size of the lens opening. For example, an aperture of f/8.0 is smaller and lets in half the amount of light of an aperture of f/4.0.
Aperture is an important parameter because it directly influences the depth of field (that is, how much of an image is in focus). A small aperture (large f-number) produces a large depth of field, meaning a considerable portion of the scene from the foreground to the background is in focus.
Shutter priority is a semiautomatic shooting mode that lets you control the speed of the shutter while the camera chooses the appropriate aperture.
The shutter speed setting controls the time the shutter stays open when snapping a photograph, measured in seconds or fractions of a second. A DSLR typically has settings from 1/4000 — a four-thousandth of a second — up to 30 seconds.
A faster shutter speed lets less light reach the sensor, freezing the exposure of fast-moving subjects and keeping them in sharp focus. Sports and other action scenes are often taken with a shutter speed of 1/2000, or a two-thousandth of a second. A slower shutter speed lets more light reach the sensor and can often depict movement with slightly blurred images.
In program mode, the photographer can set either the aperture or shutter speed and the camera will adjust the other setting to maintain the correct exposure. This mode lets you use either aperture priority or shutter priority without switching between shooting modes.
The ISO setting controls the DSLR camera sensor's sensitivity to lighting conditions. A low sensor sensitivity (low ISO number) works best for shooting in sunny environments with plenty of light available. High sensor sensitivity is best for darker conditions when proper exposure requires more light. Adjusting the ISO setting to the proper light sensitivity helps reduce noise and minimize grain.
Aperture, shutter speed and ISO are all linked. Understanding the relationship among them is essential to taking control of your camera. A change in one of the settings will affect the other two.
For example, if you want to reduce the depth of field for exposure with settings of 1/10 of a second shutter speed, f/8.0 aperture and ISO 400, you might change to an aperture of f/4.0. The increase in aperture size by two whole f/stops increases the amount of light entering the camera by a factor of four (that is, a factor of two for each f/stop).
To balance the exposure triangle, you have three options:
In most cases, when fine-tuning a photo, the aperture is the first exposure-triangle parameter to adjust. However, when capturing movement is a priority, the shutter speed is often changed first. ISO is rarely the primary configuration parameter but can be adjusted to balance the exposure triangle.
DSLR cameras typically offer several metering modes to expose a photo:
DSLR metering can seem complicated at first, but experimenting with different modes will help you determine the best method for any image.
Autofocus modes of a DSLR rely on focus points, displayed in the viewfinder as dots or squares overlaid across the screen. When the shutter release button is half-pressed, several of these may flash indicating the active focus points. Some DSLRs, such as the Canon EOS 5D Mark IV, come with over 50 focus points.
The best method to assure the correct focus is to turn off the spectrum focusing option on the menu system, enable single-point focus (usually in the center) and place the focus point over the subject.
DSLR cameras offer a range of autofocus modes. However, the two most often used are single and continuous.
A 45.7-megapixel resolution, continuous shooting speed at seven frames per second and 4K full-frame video make this Nikon camera an excellent choice for the professional photographer or serious amateur.
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High image quality with a 32.5-megapixel APS-C sensor, continuous shooting capability of 10 frames per second and uncropped 4K video capture make this Canon camera the ideal choice for the enthusiast.
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The small lightweight camera features a 24.1-megapixel APS-C sensor with Canon's Dual Pixel AF Technology and 4K video. It offers in-camera guides to help beginners achieve the best results.
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Jeff Harper writes for BestReviews. BestReviews has helped millions of consumers simplify their purchasing decisions, saving them time and money.