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How to operate a DSLR camera?

New to Photography? Check out our free Ultimate Guide to Photography for Beginners.

If you’ve bought yourself a DSLR (or mirrorless camera) and, after unpacking it from the box, you are intimidated by the number of buttons and dials, and by the thickness of the manual, it can be very tempting to put the manual down, flick it onto ‘Auto’ and start shooting.

Whilst that is fine for some, it may not be long until you crave the creative control that inspired you to purchase a DSLR in the first place, but where do you begin?

The Ultimate Guide to Learning how to use Your first DSLR

This post is for you if you consider yourself a beginner who is unsure how to make the most of your camera. It’s meant to be a quick, one-stop shop for getting your camera off auto and into control of your DSLR. It is not intended to be a replacement for your camera manual, so it will not explain every single setting in great detail, but it will cover enough of the basics to get you in control of your camera and give you the key topics to go back and read in your manual.

Steps for Learning How to Use Your DSLR include:

Here’s some steps for learning how to use that new DSLR that we’ll cover in this article.

  1. Master Shooting modes (including priority modes and full manual)
  2. Understand ISO
  3. Learn the ‘exposure triangle’
  4. Master Metering including exposure compensation
  5. Learn About Focussing
  6. Understand file size/types
  7. Learn about White balance

There’s lots to learn if you want to get the most from your DSLR but lets start by digging into each of these topics.

Note to Mirrorless Camera Ownersalmost everything in this article is relevant not only to DSLR owners but also mirrorless camera owners too!

1. Master Shooting modes

Starting with shooting modes is the best place to start. The shooting modes will most likely be found on a dial labeled ‘auto, Av, Tv, P, M,’ and possibly others. When you choose a shooting mode, it determines how your camera behaves when you press the shutter. For example, if you choose ‘auto,’ the camera will determine everything about the exposure, including the aperture and shutter speed. The other modes, ‘Av, Tv, P, M,’ are available to give you more control:

How to Use a DSLR - Shooting Modes Dial

Don’t be concerned if your mode dial differs slightly; different manufacturers use different abbreviations for the shooting modes. Although your mode dial may have the letters ‘A, S, P, M’ (rather than Av, Tv, P, M), they all function the same way. Each abbreviation for the given mode is listed below.

Aperture Priority (Av or A)
Aperture priority is similar to a semi-automatic shooting mode. When this option is selected, the aperture is set by the photographer, and the shutter speed is chosen automatically by the camera. So, what exactly is aperture, and when would you want to manipulate it?

The aperture is the size of the opening in the lens that allows light to pass through when the shutter is opened; the larger the aperture, the more light passes through.

The aperture is measured in f-stops and is usually displayed as an f-number, e.g. f/2.0, f/2.8, f/4.0, f/5.6, f/8.0, etc., which is a ratio of focal length over opening diameter. As a result, a larger aperture (a wider opening) has a lower f-number (e.g. f/2.0), while a smaller aperture (a narrower opening) has a higher f-number (e.g. f/22). Reduce the aperture by one full f-stop, for example, f/2.0 to f2/8 or f/5.6 to f/8.0, to cut the amount of light entering the camera in half.

How to Use a DSLR Aperture illustration

Aperture is one of the most important aspects of photography because it directly influences the depth of field, or how much of an image is in focus. A large depth of field (achieved by using a small aperture (large f-number)) means that a large distance within the scene, such as the foreground to the background of the landscape below, is in focus.

Learn How to Use a DSLR: landscape taken at small aperture

An aperture of f/13 was used here to give a large depth of field, ensuring that the whole image, from the foreground grasses to the background mountains. was sharp

A shallow depth of field (achieved by using a large aperture (small f-number)) would result in an image with only the subject in sharp focus and the background soft and out of focus. This is frequently used to isolate the subject from the background when photographing portraits or wildlife, as shown in the image below:

large aperture

A large aperture of f/4.5 was used to capture this water vole, against a soft, out of focus background

So when using aperture priority, you can get complete control over your depth of field, whilst the camera takes care of the rest.

Further ReadingRead more about Aperture Priority Mode.

Shutter Priority (Tv or S)
This is another’semi-automatic’ shooting mode, similar to aperture priority, but in this case, you set the shutter speed and the camera takes care of the aperture. The shutter speed, which is measured in seconds (or, more commonly, fractions of a second), is the amount of time the shutter remains open while taking a photograph. The longer the shutter is open, the more light enters the sensor and is captured.

You would select a short shutter speed if you wanted to freeze a fast moving subject, such as shooting sports, action or wildlife, for example:

fast shutter speed

A very fast shutter speed of 1/4000th sec was used to freeze the motion of this grouse in flight

A long shutter speed would be used to blur a moving subject, such as water rushing over a waterfall (slower shutter speeds will require you to use a tripod to ensure the camera is held steady while the shutter is open):

Slow Shutter Speed

To capture the motion of the waves, and render the water with a soft, milky texture, a shutter speed of 6 seconds was used here

So whilst you worry about what shutter speed you need for a given photograph, the camera will determine the appropriate aperture required to give the correct exposure.

Aperture and shutter priority shooting modes are semi-automatic, which means that some people dismiss their use because they aren’t completely manual, but they are incredibly useful modes to shoot in because they give you enough creative control to capture scenes exactly as you envision them.

Further Readinglearn more about Shutter Priority Mode.

Program (P)
Program mode is a semi-automatic mode that sits between aperture/shutter priority and full manual control. In program mode, you can set either the aperture or the shutter speed, and the camera will maintain the correct exposure by adjusting the other. For example, if you change the aperture, the shutter speed will change automatically, and vice versa. This gives you more freedom than using aperture priority or shutter priority without switching between shooting modes.

Manual (M)
Manual mode is exactly what it sounds like: you have complete control over the exposure, adjusting the aperture and shutter speed yourself. There will be an exposure indicator, either in the viewfinder or on the screen, that will tell you how under/overexposed the image will be; however, you will be responsible for adjusting the shutter speed and aperture yourself to ensure proper exposure.

Practically speaking, as a first step toward moving away from ‘auto,’ aperture priority and shutter priority modes provide two very simple ways to begin to understand how different settings impact your images and are an excellent starting point for learning how to use your camera more creatively.

2. Understand ISO

ISO is a measurement of how sensitive your camera’s sensor is to light. The term originated in film photography, where different sensitivities of the film could be used depending on the shooting conditions, and it is still used in digital photography. The ISO sensitivity ranges from ISO 100 (low sensitivity) to ISO 6400 (high sensitivity) and beyond, and it governs the amount of light required by the sensor to achieve a given exposure.

At ‘low’ sensitivities, more light is required to achieve a given exposure compared to high sensitivities where less light is required to achieve the same exposure.  To understand this, let’s look at two different situations:

Low ISO numbers
On a bright sunny day, there is a lot of available light that will hit the sensor during exposure, so the sensor does not need to be very sensitive in order to achieve correct exposure. As a result, a low ISO number, such as ISO 100 or 200, could be used. This will produce images of the highest quality with a minimal grain (or noise).


Taken at ISO 100, the image does not show signs of noise (even when looking at the 100% crop (right)

High ISO numbers
There isn’t much light available for your camera sensor when shooting in low light conditions, such as inside a dark cathedral or museum. A high ISO number, such as ISO 3200, will increase the sensor’s sensitivity, effectively multiplying the small amount of available light to produce a properly exposed image. This multiplication effect has the side effect of increasing image noise, which appears as fine grain, lowering overall image quality. The noise will be most noticeable in the darker/shadow areas.

High ISO

This image was taken as the sun was setting, so there was little ambient light. As a result, ISO4000 was used, but there is a lot of noise in the 100% crop (right)

In practice, you should keep the ISO as low as possible because the lower the ISO, the less noise and the higher the quality of the resulting image. Select ISO200 on a sunny day and see how it goes. If the sky is cloudy, choose an ISO of 400-800. Consider an ISO of 1600 or higher when moving indoors (these are approximate starting points).

Most digital SLRs now have an ‘auto-ISO’ function, in which the camera adjusts the ISO based on the amount of light available, keeping it as low as possible. Auto-ISO is a very useful tool when first starting out with your camera because it allows you to set an upper limit, such as ISO1600 or 3200, where the images become too noisy, and then forget about it until situations arise where you specifically want to override the automatic setting, such as when taking landscape images with a tripod and can afford to use the lowest ISO possible.

Further ReadingDiscover more about how to use ISO.

3. Learn the ‘Exposure Triangle’

It’s important to note that aperture, shutter speed and ISO are all part of the ‘exposure triangle’.  They all control either the amount of light entering the camera (aperture, shutter speed) or the amount of light required by the camera (ISO) for a given exposure.

Therefore, they are all linked, and understanding the relationship between them is crucial to being able to take control of your camera.  A change in one of the settings will impact the other two.  For example, considering a theoretical exposure of ISO400, f/8.0, 1/10th second.
If you wanted to reduce the depth of field, you could use an aperture of f/4.0, which would increase the aperture size by two full f/stops, increasing the amount of light entering the camera by a factor of four (i.e. increasing by a factor of 2, twice). As a result, you could do the following to balance the exposure:

  • Situation 1: Reduce the shutter speed by a factor of 4, i.e. to 1/40th second.
  • Situation 2: Reduce the ISO by a factor of 4, i.e. to ISO100
  • Situation 3: A combination of the above, shutter speed by a factor of 2 (to 1/20th second) AND reduce the ISO bv a factor of 2 (to ISO200).

Exposure triangle - DSLR Guide

Aperture, shutter speed, and ISO are all factors that influence your exposure and are all linked. It’s just a case of balancing the books!

They all have the net effect of reducing the amount of light by a factor of 4, countering the change in aperture.  It’s just a case of understanding that they are all linked, and so changing one setting will cause a change in another.

Using a combination of semi-automatic shooting modes and auto-ISO means you won’t have to think about adjusting your exposure in this way right away, but understanding the relationship between ISO and shutter speed, and understanding the practical implications, is a big step toward mastering your DSLR.

Further Reading: Read more about the Exposure Triangle.

4. Master Metering

Through out all of the above discussion, I have said that the camera calculates the exposure depending on the amount of available light, but what is it actually doing?

When taking a photograph in any mode that uses automatic exposure calculation (e.g., aperture priority mode, shutter priority mode, auto-ISO, etc.), the camera always attempts to calculate an ‘average’ exposure. It will evaluate the entire scene, including both light and dark areas, and determine the exposure so that all of the tones within the entire image average 18% grey – known as the “middle” grey.

Metering is the reason that when you point your camera at a bright white scene, such as after it has snowed, and take a photograph, the resulting image will always appear darker than you or I see it. Similarly, if you point your camera at a very dark scene, such as a dimly lit room, and take a photograph of it, the resulting image will always be brighter than you or I see it.

The camera is constantly averaging the scene, which results in the image appearing to be correctly exposed most of the time. You can, however, control which areas of the scene are assessed by the camera in order to influence how the exposure is metered.

Generally, there are three metering modes that you can choose from:

Average – The camera will assess the tones across the entire image from corner to corner, and expose the scene to 18% grey from that assessment.

Center-weighted – The camera weights the exposure reading for the area in the center of the viewfinder which can total up to approximately 80% of the scene, ignoring the extreme corners of the image.

Spot metering – The camera will use a very small area of the scene, typically a small circle in the center of the viewfinder that totals approximately 5% of the viewfinder area.  It will make the assessment of dark/light tones in this area and expose the entire scene to 18% grey, from that assessment.

In practice, either average or center weighted metering are good places to start when learning how to use your camera. They will both provide a fairly consistent measure of the exposure required, and if you stick with one mode, you will quickly begin to understand when a scene will be under-exposed (i.e. too dark) or overexposed (i.e. too light) compared to how you see it with your own eyes.

But what can you do if a scene is under/overexposed?  That is where exposure compensation comes in.

Further Reading: A Beginners Guide to Metering Modes

Exposure Compensation

This is one of the most useful functions to learn how to use and is usually found on a small +/- button near the shutter. It lets you adjust the camera’s default meter reading to account for the actual brightness of a scene.


If a scene contains primarily bright tones and is being rendered too dark, such as a bright white snow scene (which the default metering system will typically reduce to 18% grey), you can use positive exposure compensation to tell the camera that the scene should be lighter than middle grey.

exposure compensation

A lamb leaps in front of a snowy hillside in the spring. Left: Straight out of the camera, with the snow rendered grey. Right: Exposure compensation of +2 stops (added in post-processing). Because of the bright snowy background, my camera underexposed this scene by nearly two stops, which could have been corrected in camera with exposure compensation.

In contrast, if a scene contains primarily dark tones and is being rendered too light, such as a dark night scene (which the default metering system will typically increase to 18% grey), you can use negative exposure compensation to tell the camera that the scene should be darker than middle grey.

Further Reading: How to Use Exposure Compensation to Get Better Exposed Photos.

5. Learn About Focussing

Regardless of what shooting mode you are using, or what ISO you define, the chances are there will be a subject of your image that you want to have in focus.  If that focus is not achieved, the image will not be what you wanted.

Autofocus modes
DSLRs come with a range of autofocus modes, however, for simplicity, the two that are most important to understand are AF-S and AF-C

AF-S – autofocus-single.  This is best used when taking photos of stationary subjectssuch as portraits of people, landscapes, buildings etc.  When you half-press the shutter, the focus will be acquired and locked on that point for as long as you hold the button down.  If you want to change to focus, you need to release the button, recompose and then re-half-press.

AF-C – autofocus-continuous.  This is best used when taking photos of action or moving subjects such as sports and wildlife.  When you half-press the shutter, focus will be acquired and locked on to a given subject.  When that subject moves, the focus will adjust with it, refocusing all of the time until the photograph is taken.

(These modes are not to be confused with the AF/MF switches on the lens, where AF stands for autofocus and MF stands for manual focus.  That switch is an override for if you want to manually focus your lens.  If you want to make use of the autofocus modes discussed above, ensure the lens is set to AF).

Further ReadingUnderstanding Focus Modes

Focus Points
Both of these focus modes rely on something called focus points. You should see a number of squares/dots overlaid across the screen when you look through the viewfinder. When you half-press the shutter, one of these squares should be highlighted in red. That is the active focus point, and the camera is focusing on that location within the frame. The following is a viewfinder with 9 focus points:


New DSLRs can have more than 50 focus points, and it’s tempting to leave it on fully automatic focus point selection, assuming that the camera will select the correct focus point. However, only you know what you want to focus on, and there is no better way to ensure that the correct subject is in focus than by using a single focus point and positioning it over the subject.

If you choose a single focus point, you should be able to switch between them fairly easily, either by using the directional buttons or one of the dials. If you choose a focus point that is on your desired subject, the camera will focus where you want it to. With a little practice, you’ll soon be able to change the focus point without having to take the camera away from your eye.

In practice, set your camera to use a single focus point at first (your camera manual should tell you how to do this). This way, you can select what you want to focus on, ensuring that the subject you want to capture is in focus. Once you’ve mastered the basic focusing modes and focus point selection, you can move on to the more advanced modes that your camera may provide.

6. Understand File Size and Types

You will have the option of changing the size and file type of the images that your camera records. Set the file size to the largest possible (whether it is ‘large,’ ‘fine,’ or super fine’) to make the most of the megapixels that you have just purchased.

You will also be able to select whether to save the images as ‘raw’ or ‘jpeg’ files. A raw file is uncompressed and thus contains a large amount of image data, allowing for greater flexibility during post-processing (i.e. on your computer), but it also comes with additional complications such as the need to ‘process’ each file using dedicated editing software and a larger file size. A jpeg is a compressed file type that is processed automatically by the camera. They will be ‘print ready’ right out of the camera and are much smaller files, allowing you to store more images on a single memory card.

Practically speaking, using jpeg as your first camera format is the most straightforward. It will allow you to get the best results while learning the fundamentals of your camera before complicating matters with raw file post-processing.

7. Learn about White balance

If you shoot in jpeg, as recommended above, make sure to set your white balance before taking a picture. The white balance of your camera can have a big impact on the color tone of your photos. You may have noticed that your images have a blueish tint at times, while others appear very orange. This is due to the white balance, and while you can adjust the image on your computer, it is much easier if you get it right the first time.

Different light sources (such as the sun, light bulbs, fluorescent strips, and so on) emit light with different wavelengths and thus colors, which can be described by color temperature. Light from a candle or the sun at sunrise/sunset is very warm and contains many red/orange wavelengths, whereas light from a fluorescent strip is much cooler and contains many blue wavelengths. This coloured light is reflected off surfaces, but our brain is smart enough to recognize this and automatically compensate, so we still see a white surface as a white surface. However, your camera is not that intelligent and, unless instructed otherwise, will record the orange or blue tones that give your images a color cast.

white balance

Left: The image captured using auto white balance has a heavy yellow tone from the artificial street lighting. Right: the same image, corrected for a ‘Tungsten’ white balance, giving the cooler tones on the stone work, and the bluer sky

As the color temperature of various light sources is well known, there are a number of presets built into your camera that help to overcome the different colors of light in different situations – cooling the warm light and warming the cool light – all in the name of accurately capturing the colors of the scene. The ‘auto’ feature (auto WB or AWB) will attempt to predict the color of the light by detecting the dominant color of the scene and then counteracting it, but it may not always make the correct decision, leaving you with incorrect colors. Therefore it is best to set the colour balance before you take your image and just to make sure (note: the above image was a raw file giving me a lot of latitude for white balance correction.  Jpeg files are not as susceptible to white balance adjustments, meaning the white balance correction needs to be made before the image is taken):

Daylight – To be used on clear sunny days.  Bright sunlight, on a clear day is as near to neutral light that we generally get

Cloudy – To be used when shooting on a cloudy day.  Adds warm tones to daylight images.

Shade – To be used if shooting in the shade, as shaded areas generally produce cooler, bluer images, so need warming up.

Tungsten – Used for shooting indoors, under incandescent light bulbs, or under street lights, to cool down the yellow tones.

Fluorescent – Compensates for the green/blue tones of fluorescent light strips when shooting indoors.

Flash – the flash will add a cool blue cast to the image, so used to add some warmth.

In practice, avoid using auto white balance and instead adjust the white balance manually. In general, you should be able to look up at the sky and tell what kind of day it is, as well as determine the color balance required, fairly easily. If you move indoors, simply check the lighting and select the appropriate white balance. It will soon become second nature to set it as you take your camera out of the bag.

Further Reading: Learn more about White Balance


So that’s an overview of the settings you’ll encounter if you decide to ditch ‘Auto’ mode on your camera. You don’t have to think about them all at once, but exploring and understanding the effects of each setting will soon have you in complete control of your camera. The most important step, which will give you the most noticeable difference in the feeling of control and direct influence on creative results, will be to begin using ‘aperture priority’ or shutter priority’ shooting modes, and once you are familiar with those, you can begin to think about exploring further. Soon enough, you will no longer think of your camera as a mysterious black box, but understand how to achieve the photographic results that you bought it for in the first place.



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