What Is A DSLR Camera? (The Beginner Guide)

DSLRs (Digital Single Lens Reflex Camera) are a popular camera choice for every amateur, enthusiast or professional photographer since they can work with many interchangeable lenses.

So what exactly is a DSLR camera? How does it work? Are DSLR cameras still worth buying today? 

As a photographer with five years of experience, I often get asked this from new photographers.

In this article, I will help you understand what a DSLR is and how it works. Moreover, if you are looking for a DSLR camera as a beginner, this article will provide useful information before you buy. 

Dslr Camera guide

What is a DSLR Camera?

DSLR cameras have almost become synonymous with “professional cameras” or “digital cameras.”

The abbreviation DSLR stands for “digital single lens reflex”, which means “digital single lens reflex camera”.

DSLR cameras combine a digital sensor to record images and a single-lens reflex camera.

The good thing about single-lens is it allows the camera to focus, frame, and take pictures with the same lens.

Reflex refers to the reflex mirror inside the camera body, which directs light from the camera lens to the optical viewfinder, so the user can see what you’re shooting, right through the lens.  

The DSLR cameras have the outstanding feature of allowing interchangeable lenses on the same camera body compared with many other types of digital cameras out there, like SLR and mirrorless cameras.

During the 2000s, DSLR cameras took over film-based SLRs when digital photography became a trend. While since the 2010s, smaller mirrorless cameras have become more and more popular.

This Is How a DSLR Camera Works

Light travels through the lens mount of a digital SLR camera to a mirror, where the light is reflected into the optical viewfinder, which enables you to see the object you’re shooting through the camera lens in real-time.

When you press the shutter release button, the light goes into the digital image sensor via the mirror’s reflection. So the picture is finally taken with the digital image sensor. 

Unlike DSLR cameras, mirrorless cameras don’t have any mirrors to reflect light when you’re photographing just like their name implies.

Instead, light goes straight to the mirrorless camera image sensor to view the scene you’re capturing via either a rear LCD screen or an electronic viewfinder. 

DSLRs also have LCD screens, like mirrorless cameras. This is handy for situations where you can’t use an optical viewfinder, say taking underwater photos.

How a DSLR Camera Work Guide

Types of DSLR Image Sensors

All DSLR image sensors are not the same. The two main types of DSLR image sensors are CMOS sensors and CCD sensors.

CCD technology was developed more than 20 years ago for the camera industry. A CCD sensor is smaller than a CMOS sensor, and also more sensitive in lower light conditions than the counterpart.

Meanwhile, CMOS technology is now reaching maturity, and CMOS sensors are taking the place of CCD sensors because the CMOS sensors offer the most advantages:

  • faster reading time
  • less reading noise
  • better sensitivity to light
  • better dynamics
  • cost less to manufacture
  • use less power

CMOS Sensor vs CCD Sensor: What to Choose

Is the CCD totally outdated and the CMOS is superior in all respects? In reality, there is no simple yes or no answer to this question and we can’t give you straightforward advice.

For a long time in the early 2000s, the competition between CCD and COMS sensors was fierce. For one year, the best sensors were CCDs; the next, CMOS, then CCDs again, and so on.

Today, most DSLR cameras use CMOS sensors because cameras with CMOS sensors cost less to manufacture than CCD sensors. 

However, one day we may have a chance to witness the great return of the CCD. 

Sensor Size: Full frame vs APS-C

The sensor size inside the DSLR camera body determines camera’s quality and price. 

The two main DLSR camera’s sensor sizes are 35mm full-frame (35mm sensor) and APS-C or crop sensor

1. 35mm Full-Frame Sensor

As the standard sensor, the full-frame sensor has the exact dimensions as the 35mm film format, typically 36×24mm; hence it’s also called a 35mm sensor.

With a wide field of view and a large sensor, the 35mm full-frame sensor can produce the highest-quality images that many professional photographers enjoy.


  • Larger, more comfortable optical viewfinder
  • Better image quality, especially in low light
  • Better Bokeh (background blur)
  • Shallow depth of field
  • Higher dynamic range


  • More expensive to buy
  • Optical defects are more visible
  • More expensive to buy telephoto lenses (200mm and more)
  • Weight of heavier files
  • Bodies and lenses are quite bulky and heavy

Be aware that 35mm full-frame sensors are available in both DSLR and mirrorless cameras.

2. APS-C

APS-C is slightly smaller than a 35mm sensor. APS-C captures a cropped version of its full-frame sensor, resulting in a shorter focal length called “crop factor”, hence it’s also called a crop sensor.

The typical APS-C sensor size is varied from the camera brand. For example, Sony APS-C sensors are usually 23.6×15.6mm in dimension, while Canon features 22.3×14.9mm APS-C sensors.


  • Cheaper to buy
  • Fewer optical defects
  • Lighter bodies and lenses
  • Affordable telephoto lenses
  • Greater depth of field


  • Smaller optical viewfinder
  • Slightly poorer image quality, less efficient in low light
  • Less dynamic range
  • Difficult to get a wide angle 

APS-C sensor size is very popular in both DSLR and mirrorless cameras. Note that sensor size does not affect image size. This is not about image size.

Full-frame vs APS-C: What to Choose?

The choice of image sensors impacts the type of lenses you use, and their cost. So you should think carefully before buying a DSLR. 

A full-frame sensor offers an undeniable advantage in landscape photos (for the dynamics and the quality), and the portrait (for the Bokeh).

On the other hand, many street, architectural, or landscape photographers look for pictures with a great depth of field. This is where an APS-C sensor has an advantage over a full-frame sensor, because, at the same aperture, you have a greater depth of field.

In fact, many professional photographers don’t choose but take both. A full-frame DSLR camera is the main work tool and an additional APS-C DSLR as a backup to take images that are difficult to achieve in full format.

Are Full-frame and APS-C Compatible?

The short answer is No. APS-C and full format are not incompatible but only work in one direction. This is quite important to take into account when buying lenses. 

  • Lenses for full-frame sensor cameras are compatible with an APS-C sensor body – their focal length will be multiplied by a value of X1.5 to X1.7 depending on the brand. 
  • Lenses for APS-C sensor cameras are not compatible with a full-frame sensor body. If you can put it on the camera, you will see a noticeable vignette effect on the edges of the image.

If you are thinking of buying lenses for full-frame sensor DSLRs, you have to be careful. Be sure to check that your lens is indeed full format compatible (abbreviation FX at Nikon, EF at Canon, FE at Sony which indicates that it’s full-frame).

DSLR Advantages

Taking pictures with a DSLR has more advantages than point-and-shoot cameras. The following are a few critical advantages of DSLRs: 

1. Interchangeable Lenses

Most digital cameras don’t have the option to change the lens while the big advantage of DSLR cameras is they have interchangeable lenses. This offers you more options for focal length than with point-and-shoot models.

People often say no lens is perfect for any situation. Yes, it’s true. For this reason, DSLR cameras have many types of lenses that serve different purposes. 

Think of a portrait lens, macro lens, wide-angle lens, fisheye lens, and telephoto zoom lens with which you can do a lot of different things. 

For example, if you like taking landscape photos, then you put a wide-angle zoom lens on your camera to capture vast landscapes. 

If you like to take sports photos, a telephoto lens with a shallow depth of field is great to get rid of the busy background.

For taking portrait photos, if you want to make the background blurry,  then you need a prime lens for its wide aperture and sharper images. 

2. Better Image Quality

When it comes to image quality, the best options on the market are DSLR cameras and mirrorless cameras.

This is because DSLR cameras typically feature larger sensors (APS-C or full-frame) than point-and-shoot digital cameras.

The larger sensor means, the lesser digital noise the image gets, and the higher the megapixel, resulting in better image quality. 

For this reason, DSLR cameras are generally better suited for capturing great images.

3. Better Sensitivity in Low Light

One significant feature of DSLRs is ISO which makes the digital imaging sensors more sensitive to light than point-and-shoot digital cameras.

In low-light environments and other challenging lighting situations, DSLRs are more reliable than point-and-shoot cameras, and easier to use and shoot with.

You can take pictures in the best way possible by increasing ISO, with just little noise in image quality.

4. Better Shutter and Focus Speeds

A DSLR features a mechanical shutter capable of focusing very fast and taking multiple images per second. This is quite useful, especially when shooting action photography, like wildlife or sports photography.

On the other hand, compact cameras have an electronic shutter that is slower than a mechanical shutter. 

5. Flexible Controls

DSLRs typically have more buttons and controls than film cameras / point-and-shoot cameras.

This means rather than letting the camera make choices, DSLRs offer manual control over all the important parameters.

You will have flexible control over the scene when you’re shooting, like customizing your camera’s settings and using the camera’s best features as quickly as possible, 

The Advantage of DSLRs

DSLR Disadvantages

Like a coin has two sides, there are cons to DSLR cameras. Below are some considerable downsides of DSLR cameras:

1. High Price

DSLRs are more expensive than point-and-shoot cameras since DSLRs have more features, and inner and outer components, and capture high-quality images.

A typical entry-level camera with a kit lens will cost you around $500 or more.

Moreover, you’ll have to invest more money in good lenses, which are a big expense besides the camera itself. 

2. Additional Costs of Accessories

You may have to cash out on the accessories to help your camera work.

Depending on the type of digital photography you’re shooting, the following accessories can also be just as important for you:

  • straps
  • tripods
  • filters
  • external flashes
  • memory cards
  • and camera bags

On the other hand, point-and-shoot cameras have everything already pre-built.

3. More Weight and Size

DSLR cameras are usually larger and heavier than point-and-shoot cameras.

The average DSLR weight is around 675.3 g, while a point-and-shoot camera weighs less than 300 g, much less than DSLRs. You may suffer back or neck pain from carrying a DSLR camera around.

Traveling with large, fragile, heavy, and expensive DSLR cameras can be a nerve-wracking experience for you. You’ll have to choose what to bring, and what not to bring, and learn how to pack your DSLR camera gear safely.

However, if weight and size are not an issue, you won’t regret getting a feature-heavy, full-frame DSLR camera that produces higher-resolution images. 

4. Big Learning Curve

Due to DSLRs’ many features and buttons, you‘ll have to spend a lot of time learning how to use a DSLR and improve your DSLR Photography skills. Beginners could quickly feel frustrated.

However, once you overcome the frustration in the process where learning is painful, you start reaching the part where the process is enjoyable and memorable. As always, just be patient.

The Disadvantage of DSLRs cameras

What Is a DSLR: Factors to Consider When Buying a DSLR

If you are a beginner photographer and just starting to look for what kind of DSLR you will need, then there are a few questions you will want to ask yourself before making your buying decision.

1. What Do I Want to Shoot?

The most important question that a beginner photographer has to ask himself is what he actually wants to shoot.

The question of “what” is essential because every camera has its own strengths. There is no such thing as the best camera for every photographer. But there is the best camera for certain type of photography. These include:

  • Portrait photography: The most popular and probably best-known style of photography where people play the most important role.
  • Landscape photography: One of the most popular styles of photography that focuses on nature. 
  • Street photography: Capture candid scenes in urban space and shoot portraits of strangers, architecture, etc.
  • Food photography: Food as the main subject is beautifully presented in a pleasant way for the viewer.
  • Wedding photography: The candid moments of a wedding ceremony, and reception in a couple’s life, captured by the wedding photographer.
  • Architectural photography: It is a genre of photography capturing buildings or structures and their details.
  • Sports photography: This style thrives on capturing action and movement in sporting events.
  • Macro photography: It’s all about showcasing the smallest creatures and details, mostly from nature.
  • Newborn photography: Newborn photography is a style of photography that captures pictures of human babies within the first 14 days. Babies sleep most of the day during this time.
  • Real Estate Photography: Real estate photographers photograph commercial and residential properties from a certain angle. They capture a house not only from the outside, but also from the inside.
  • Fashion photography: Fashion photography is a popular type of photography that show clothing or accessories for fashion magazines or fashion catalogs.
  • Astrophotography: The photography of an object in space, including stars, planets, the moon, galaxies, comets, and other celestial bodies.
  • Documentary photography: This genre captures authentic images of people, places, and events that are historically or socially significant. Often used to point out problems.
  • Experimental photography: As a sub-area of ​​artistic photography, experimental photography is consciously using your camera in a non-traditional way on the playful, abstract, and experimental.
  • Nude photography: Nude photography is the artistic depiction of a nude or semi-nude person, yielding amazing images.

2. What is Your Budget?

Like cars, cell phones, or other items you can buy, there is a wide price range for DSLRs, usually from $500 to $5,000.

The amount of money you will spend on a DSLR depends on your photography goals with this camera and your income.

At this point, it’s quite important to set a budget before you go shopping in a camera store.

For example, if your budget is below 150-200 USD,  taking real pictures with a smartphone is a good start. That’s what a lot of photographers did when they began.

Smartphones have improved significantly over the years. You can practice taking pictures with a phone camera while continue to save for a future purchase. 

If your budget is about 300 – 400USD, consider opting for second-hand DSLR cameras which is a bargain for a beginner.

You will find DSLRs 2 to 3 years old, which are slightly used and will be enough to start with.

You will probably be much happier than a brand new compact camera. Don’t be fooled by stuff like GPS and the like: it’s not essential.

If you have more than 400-500 USD, then choose a DSLR. Even entry-level, you will really enjoy yourself with it. 

3. Am I Comfortable Holding a Large Camera?

You should hold the camera still to reduce the camera shake if the tripod is not available to get sharp images.

If you are a tiny person, you may not feel comfortable holding a large camera in the field all day.

In a nutshell, you need a DSLR with a proper size that fits your usage habits regarding the camera’s size and weight. 

4. How Much Control Do I Want to Have?

If you wish to press a button and let the camera do all the work, you may not need a DSLR. A point-and-shoot camera can suit all your needs.

However, if you like to control the settings, like ISO, white balance, depth of field, shutter speed, etc. you probably want a DSLR that allows for many adjustments.

With a DSLR, you can easily adjust the settings to create the effect you prefer when shooting portraits, sports, wildlife, etc.

Mirrorless or DSLR, Which One is Better

Mirrorless or DSLR, Which One is Better?

It seems increasingly that professional photographers are going for mirrorless cameras, given that in the past, if you were a pro, you always bought a  DSLR.

Moreover, the world’s biggest camera brands, like Sony, Canon, and Nikon, are putting their energy into producing better and better mirrorless cameras. 

On the other hand, DSLRs tend to be larger and heavier than mirrorless cameras.

DSLRs usually have excellent battery life for longer shoot days, as their optical viewfinder consume less battery power than a mirrorless camera’s electronic viewfinder does.

Plus, DSLRs offer you speedy autofocus.

DSLRs can also shoot video that’s fine for amateur photographers, but mirrorless cameras can better capture 6K and 8K, a raw or 10-bit video that most DSLRs cannot match. 

Furthermore, DSLRs are a better choice for lenses than mirrorless cameras because many manufacturers have supported them for quite a long time.

However, major camera manufacturers like Sony, Canon and Nikon are focusing their energy on developing mirrorless lenses. So mirrorless lenses might have a potentially positive future ahead.

What to Choose?

Buying a new camera isn’t easy. What type of camera to buy depends on the subject you want to shoot and your budget. It’s about finding the camera that’s right for you.

But whichever kind you purchase, keep in mind your photography skills are far more important than the camera body.


DSLRs are fantastic ways to learn your photographic craft for many new photographers because they are often the best for the job.

There are some important differences between DSLRs and mirrorless cameras. Understanding these differences definitely helps you choose the right camera to suit your needs.

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