A Beginner’s Guide to Cameras – Camera Parts, Exposure and Camera Accessories

In this guide, we’ll look at how a camera works, what parts it consists of, and what camera equipment a photographer actually needs. At the end, you’ll find a photography glossary explaining the most common terms. If you’re still wondering which camera to buy, have a read of Our guide to choosing a camera.

• How does the camera work?
• Camera parts
• The exposure triangle: shutter speed, aperture and ISO
• A brief overview of camera types
• Lenses
• Camera equipment: what do you need?
• Cameras and equipment used
• Photographic glossary

How does the camera work?

The camera captures light. When you press the shutter button, the light passes through the camera in the following order:

1. Lens It collects light and focuses it onto the sensor. The focal length of the lens determines how wide an area is captured in the image.
2. Opening A mechanism inside the lens controls how much light passes through.
3. Closed opens and allows light to reach the sensor for the duration of the shutter speed, for example 1/250 of a second.
4. Cell converts light into an electrical signal, and the camera’s image processor takes a photo of it.
5. The finished image is saved on a memory card As a JPEG or RAW file.

In a mirrorless camera The light hits the sensor directly, and you can see the image through the electronic viewfinder or on the rear screen exactly as it will be captured. In a digital single-lens reflex (DSLR) camera The mirror directs the light into the optical viewfinder and only moves out of the way when the picture is taken. Mirrorless cameras are now by far the most popular choice, as they are smaller, quieter and have lightning-fast autofocus.

Camera parts

Part	What does it do?
Frame	The camera’s ”body”, which houses the sensor, shutter, processor, battery and controls.
Bayonet	Lens mount. The lens mount must be the same as that of the camera body, for example Sony E or Canon RF.
Lens	Collects and focuses light. Determines the angle of view and the aperture.
Cell	The camera’s ”film”. A larger sensor (full-frame) captures more light than a smaller one (APS-C).
Closed	Determine how long the light strikes the sensor.
Search and display	An electronic or optical viewfinder and a rear display for framing shots and viewing images.
Control dials	Shooting mode (P, A, S, M), shutter speed, aperture and ISO.
Lightning Boot	Mount for a flash, transmitter or microphone.
Battery and memory card slot	Power supply and image storage, usually on an SD or CFexpress card.
Connections	USB-C for charging and data transfer, HDMI for the display, and a microphone and headphone jack for video.

The exposure triangle: shutter speed, aperture and ISO

The greatest strength of a system camera is creative freedom. Instead of using automatic mode, you can control the three most important settings yourself – known as the exposure triangle. All three affect the brightness of the image, and each also has its own side effects.

Adjustment	More light	Side effect
Closing time	A longer duration, e.g. 1/30 s	The movement appears blurred
Opening	A smaller f-number, e.g. f/1.8	The background becomes blurred (shallow depth of field)
ISO	A higher number, e.g. 3200	There is noise in the picture

Shutter and closing time

There is a shutter curtain in front of the camera’s sensor. The shutter speed indicates how long the curtain remains open to allow light to reach the sensor.

Short exposure time (e.g. 1/1000 s) freezes even the fastest motion with sharp clarity. It’s the perfect choice for sports, photographing pets or capturing water droplets.

Long exposure time (e.g. 1 s or longer) turns movement into art. It allows you to capture the stars in the night sky as streaks or a waterfall flowing with a silky softness. A sturdy tripod is essential when using long exposure times.

Aperture size

The adjustable aperture inside the lens acts like the iris of the eye: it regulates the amount of light reaching the sensor. The size of the aperture is measured using f-numbers.

A small f-number (e.g. f/1.8) refers to a wide aperture. It lets in plenty of light and creates a shallow depth of field, which beautifully blurs the background and makes the subject stand out. This is the secret to portrait photography.

High f-number (e.g. f/11) refers to a small aperture. It produces a wide depth of field, in which the entire scene is rendered sharply, from the rocks in the foreground to the mountains on the horizon. This is a landscape photographer’s essential tool.

ISO value

The ISO value measures the sensitivity of the camera’s sensor to light.

Low ISO value (e.g. 100) is the default setting in good lighting conditions. It produces the clearest and most detailed image quality.

High ISO value (e.g. 3200) is your saviour in low light. It allows you to take handheld shots in atmospheric interiors or at dusk without using a flash. Modern cameras handle the noise associated with high ISO settings exceptionally well.

White balance

White balance (WB) is the camera’s colour perception. It ensures that white looks white and other colours are reproduced naturally, whether you’re taking a photo by candlelight or in bright sunlight. The automatic setting often works well, but you can also use scene-specific presets or adjust the balance manually. In RAW images, the white balance can be further adjusted during post-processing.

A brief overview of camera types

• Compact cameras, or ‘point-and-shoots’: fixed lens, compact size and easy to use.
• System cameras: interchangeable lenses, which allow the same body to be used for landscapes, portraits and sports. Among the most popular are, for example, Sony’s A7 series full-frame cameras.
• Video cameras: improved ergonomics, professional-grade audio connections and long battery life for longer production runs.
• Action cameras: They can withstand knocks, water and high speeds. Attach them to a helmet, bike or kayak.
• Drones: open up entirely new perspectives on the depiction of landscapes, events and properties.

A comparison of camera types and our recommendations for different types of photographers – such as vloggers, nature photographers or family photographers – can be found from the camera selection guide.

Lenses

The lens often has a greater impact on image quality than the camera body. It determines how much of the landscape fits into the frame, how close you can get to distant subjects, and how well you can take photos in low light. A fast lens (small f-number) lets more light reach the sensor, so you can use a shorter shutter speed or a lower ISO setting. Always check that the lens mount is compatible with your camera body.

• Kittilinssi: The versatile zoom lens that comes with the camera, for example 28–70 mm. An excellent starting point until you find your own style of photography.
• Wide angle lens (less than 35 mm): landscapes, architecture and confined interiors.
• Fixed focal length (e.g. 50 mm f/1.8): fast, sharp and affordable. Blurs the background beautifully.
• Telephoto lens (over 70 mm): nature and sport. Capture shy animals without disturbing them, or film sporting events from the sidelines.
• Macro lens: insects, dewdrops and product images in their natural size. Read more from the macro photography guide.

We discuss the choice of lenses and mounts in more detail in the article choosing a lens.

Camera equipment: what do you need?

The right camera accessories aren’t just extras. They make photography smoother and open up new creative possibilities. We recommend purchasing these accessories to go with your new camera, in this order.

Firstly: a memory card, a spare battery and a bag

• Memory cards: A fast and reliable memory card is essential, particularly for continuous shooting and video. Check which type of card your camera supports (SD, CFexpress) and always carry a spare card with you. It’s a cheap form of insurance.
• Spare battery: The worst enemy on a photography trip is a flat battery. Make sure you have at least one spare battery so you don’t run out of power just when the perfect moment arrives.
• Camera bag or rucksack: protects equipment from knocks, rain and dust, and keeps lenses in good condition.

When photography inspires: a tripod, filters and a shutter release

• Pedestal: ensures sharp images when the light fades or when you use creative, long exposure times.
• Filters: A UV filter protects the front element of the lens, a polarising filter eliminates reflections and deepens the blue of the sky, and an ND filter enables long exposures in daylight.
• Triggers: By using a remote or cable release, you can prevent the camera from shaking on its tripod whilst taking photos. The perfect tool for landscape and macro photography.

Lighting and video: flashes, light modifiers and rigs

• Flash and transmitter: when the flash is detached from the camera and fired via a transmitter, light can come from any direction.
• Umbrellas and softboxes: In the studio, umbrellas are not used to protect against the rain, but to manipulate the light. Light reflected from the flash or fired through it becomes soft and flattering.
• Microphone: The camera’s built-in microphone is often the weakest link in a video. A separate microphone improves sound quality more than any other single purchase.
• SmallRig: SmallRig’s cages and accessories turn your camera into a modular workstation to which you can attach a microphone, a screen and handles.

Maintenance: cleaning equipment and cell cleaning

A blower, lens cloth and cleaning fluid will keep your lenses and viewfinder clean. Dust that has settled on the sensor appears as dark spots in your photos, particularly at small apertures. We’ll clean the sensor for you at our Kouvola branch.

Cameras and equipment used

High-quality photographic equipment is built to last, so buying a second-hand camera or lens is a smart way to get more value for your money. In private sales, the seller may not necessarily know what they are selling or how to assess its condition, let alone offer a warranty.

At Foto Monza, every second-hand product is tested before sale, and it has 90-day warranty and 30-day right of return. We process an average of more than 10 second-hand items every day. Each item is given a condition rating on a scale of 1–5, and any signs of wear are specifically mentioned in the product description. Read more Fitness classifications with illustrated examples.

You can sell your old cameras and lenses sell to us or provide in exchange for the price of a new camera. We usually assess products within 24 hours of their arrival.

Photographic glossary

• APS-C: A standard sensor size that is smaller than a full-frame sensor. APS-C cameras have what is known as a ‘crop factor’, which makes the lens appear to have a longer focal length. For example, a 50 mm lens corresponds to a focal length of approximately 75 mm on an APS-C body.
• Opening: An adjustable aperture inside the lens that controls the amount of light reaching the sensor. It is expressed as an f-number (e.g. f/1.8, f/4). A small f-number indicates a wide aperture and a shallow depth of field.
• Bayonet: (English: lens mount) the mechanical and electrical connection between the camera and the lens. The lens mount must be the same as that on the camera body, and mounts from different manufacturers are not compatible with one another. Tip: in the lens section You can filter lenses by bayonet mount.
• Electronic viewfinder (EVF): The viewfinder on mirrorless cameras, which is essentially a small screen. It shows you exactly what the final image will look like in terms of exposure and colours.
• FPS (Frames Per Second): indicates how many frames the camera captures per second in continuous shooting mode. A high FPS is important for sports and action photography.
• ISO: the sensor’s sensitivity to light. A low ISO (e.g. 100) produces the best quality in bright light, whilst a high ISO (e.g. 3200) allows you to take photographs in low light.
• JPEG: the most common and convenient image format. The camera processes the image so that it is ready to be shared, but there is less scope for post-processing than with a RAW image.
• Kenno: the digital heart of the camera, which captures the image. The size of the sensor has a direct impact on image quality, particularly in low light.
• Image stabilizer: A mechanism built into the camera body (IBIS) or the lens that reduces blur caused by camera shake. Extremely useful when shooting handheld, in low light and with telephoto lenses.
• Megapixels: indicates how many millions of pixels make up an image. A higher number allows for larger prints and tighter cropping.
• Optical viewfinder: The viewfinder on a digital single-lens reflex (DSLR) camera, where you look through the lens via a mirror and a prism. The view is natural and lag-free.
• Burning range: A value expressed in millimetres that indicates the lens’s angle of view. A short focal length means a wide field of view; a long focal length means a narrow one.
• RAW: digital negative. This file format captures all the data collected by the sensor and offers maximum freedom for post-processing.
• Closing time: the length of time the shutter remains open, allowing light to reach the sensor (e.g. 1/1000 s, 1 s). A short shutter speed freezes motion, whilst a long one creates motion blur.
• Depth of field: the depth of field of the image. With a wide aperture (e.g. f/1.8), only the subject is in focus and the background is blurred; with a narrow aperture (e.g. f/11), the entire image is in focus.
• Full-frame: a sensor size equivalent to traditional 35 mm film. Popular amongst professionals and discerning amateurs thanks to its image quality and low-light performance.

Frequently asked questions

What camera equipment does a beginner need?

Start with a memory card, a spare battery and a camera bag. Once you’ve got the photography bug, the next good investments are a tripod, a polarising filter and a fast fixed-focal-length lens, such as a 50 mm f/1.8.

What are the most important parts of a camera?

Lens, aperture, shutter and sensor. The lens collects light, the aperture and shutter control the amount of light, and the sensor captures the image. The body also contains a processor, viewfinder, display, battery and memory card slot.

What is the exposure triangle?

The exposure triangle refers to the interplay between shutter speed, aperture and ISO. When one of these is changed, the other two must be adjusted to keep the brightness of the image the same.

Do all lenses fit all cameras?

No. The lens mount must be the same as that on the camera body, for example Sony E, Canon RF, Nikon Z or Fujifilm X. In some cases, older lenses can be used with an adapter.

Is it worth buying a second-hand camera?

It’s worth it when you buy from a reliable seller. Foto Monzan’s second-hand products have been tested and come with a 90-day warranty and a 30-day returns policy.

Remember, the best camera is the one that inspires you to take photos. Come and explore our range online or at our Kouvola shop, and have a chat with our experts!

Also check out our photographer's quick guides