Most camera manufacturers have their own lens mount, the Canon EOS R mirrorless camera series uses and RF lens mount, and similarly the Nikon mirrorless Z series uses Nikon Z lenses. You can always find the lens mount near the beginning of the name of the lens. This rule isn’t so clear cut when it comes to micro four thirds lens mounts when using Panasonic and Olympus cameras, but with a little research it will start to make more sense.

With lenses, such as a 24-70mm lens, the focal length of the lens is specified in the name. A 24-70mm lens is a zoom lens which can capture a wide angle through to a portrait. An 8mm lens is called a fisheye lens and has a whopping 180˚ angle of view, whereas an 800mm lens might have an angle of view of 3˚.

We group lenses into their focal lengths. Any lens less than 24mm is considered wide angle. Between 24mm and 50mm is a standard lens. From 50mm up to 85mm are portrait lenses. The lenses from 85mm up to 200mm are called telephoto lenses, and the lenses from 300mm and above are called super-telephoto lenes. There are also tilt-shift lenses for architecture photography and product photography, and then macro lenses for capturing detail.

A prime lens is a lens which has a set focal length, the most common being 35mm, 50mm and 85mm. Prime lenses are great because they only have one job to do and they do it really well, often with the benefit of allowing more light in through a larger aperture, what photographers refer to as a “fast” lens.

Zoom lenses usually come in two flavours: Constant or Variable aperture. Constant aperture lenses have a single number written as their aperture value, such as f/4, f/2.8, f/1.2. They’re usually reserved for professional quality zoom lenses as they will constantly remain at their maximum aperture if you’re shooting in Aperture Priority or Manual modes.

Variable aperture zoom lenses will have a maximum aperture which varies depending on how zoomed in you are. You can see examples of these when the focal length is hyphenated, such as a 12-60mm f/3.5-5.6 lens. In this example, at 12mm the maximum aperture is f/3.5 at 60mm the maximum aperture is f/5.6, which would result in a lot of consistency between your photos if you’re not conscious of it.

Similar to Nikon, not all Canon lenses are compatible with all Canon cameras.

Canon uses different lens mounts for DSLR and mirrorless cameras. EF and EF-S lenses are primarily for DSLR cameras, while RF lenses are designed for mirrorless cameras.

Not all Nikon lenses are compatible with all Nikon cameras.

Nikon uses different lens mounts for different camera series. For example, DX lenses are designed for Nikon DX-format cameras, while FX lenses are for FX-format cameras. Some newer Nikon cameras offer compatibility with older lens mounts through adapters.  

While you can interchange lenses within a compatible system, it's essential to check the lens mount and camera format to ensure they are compatible.
Different camera brands (like Canon, Nikon, Sony) use different lens mounts. This means a Canon lens won't fit directly on a Nikon camera without an adapter.
Even within the same brand, camera formats (full-frame vs. crop sensor) can affect lens compatibility.

Not directly. DSLR and mirrorless cameras have different lens mounts.

However, you can often use DSLR lenses on mirrorless cameras with the help of an adapter. This can sometimes affect image quality and autofocus performance.

Yes, EF lenses (Canon's DSLR lens mount) can be used on Canon mirrorless cameras with an appropriate M adapter.

However, as with other lens adapters, there might be limitations in autofocus and image stabilisation.

Yes, DX lenses can be used on FX-format Nikon cameras.

However, the image will be cropped to the DX format, effectively reducing the image resolution.

To protect your lenses, store them in individual lens pouches or compartments within your camera bag. Avoid placing heavy items on top of them. When storing lenses for extended periods, remove any filters or lens caps.

Most camera lenses are not waterproof. Some professional-grade lenses offer weather sealing, but this doesn't guarantee complete protection against water. Using waterproof lens covers or protective cases can help.