Tips for using a DSLR camera
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.
How does a DSLR camera work?
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.
Which camera shooting modes should you use?
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 mode
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 mode
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.
ISO setting controls light sensitivity
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.
How to use the exposure triangle of aperture, shutter speed and ISO
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 an 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:
- Reduce the shutter speed by a factor of four, to 1/40 second.
- Reduce the ISO by a factor of four, to ISO 100.
- Reduce the shutter speed by a factor of two, to 1/20 second, and reduce the ISO by a factor of two, to ISO 200.
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.
Which metering method produces the best exposure?
DSLR cameras typically offer several metering modes to expose a photo:
- Evaluative Metering (Canon) or Matrix Metering (Nikon): The most complex metering method on the camera, it measures the brightness levels across the entire frame to determine a suitable exposure.
- Partial metering: Available on Canon DSLR cameras only, this method meters the portion of an image inside a circle visible in the viewfinder. Typically less than 20% of the frame, the focal point determines the portion of the image measured.
- Center-weighted metering: Like partial metering, this method reads a larger section in the center of the image. It tends to overexpose bright areas in the center of an image with a dark background, making it the least used metering method.
- Spot metering: This method reads the light from a focus point of choice, usually much less than 10% of the frame. Photographers use this mode to determine the proper exposure for a specific part of the image.
DSLR metering can seem complicated at first, but experimenting with different modes will help you determine the best method for any image.
Which focusing modes produce the clearest results?
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.
- Autofocus-single, also known as AF-S, works best for taking photos of stationary subjects such as landscapes, buildings and people portraits. When the shutter release is half-pressed, the camera acquires the focus, and it remains locked on the focus point while the button is held down. To change the focus, release the button, recompose and then half-press again.
- Autofocus-continuous, also known as AF-C, is most effective for taking photos of moving subjects and action events such as sports. Like the AF-S mode, the camera acquires the focus and stays locked on the subject. However, if the subject moves, the focus adjusts with it until the photo is taken.
Best DSLR cameras
Best DSLR for professional photographers
A 45.7-megapixel resolution, continuous shooting speed at seven frames per second and 4K full-frame video make this camera an excellent choice for the professional photographer or serious amateur.
Where to buy: Sold by Amazon
Best feature-rich camera at a reasonable price
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 camera the ideal choice for the enthusiast.
Where to buy: Sold by Amazon
Best DSLR camera for the novice
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.
Where to buy: Sold by Amazon
Want to shop the best products at the best prices? Check out Daily Deals from BestReviews.
Sign up here to receive the BestReviews weekly newsletter for useful advice on new products and noteworthy deals.
Jeff Harper writes for BestReviews. BestReviews has helped millions of consumers simplify their purchasing decisions, saving them time and money.
Copyright 2022 BestReviews, a Nexstar company. All rights reserved.