Camera Lenses Explained – The Definitive Guide

In this camera lenses explained guide, we’re going to give you the complete run-down on everything you need to know about camera lenses.

After all, without a lens, your DSLR camera is as good as useless. The lens you clip on is what manipulates the light and focuses it on to the sensor, so whilst any old lens will produce something, it’s the quality and function of specific lenses which will have a huge influence on the result of your photography.

This is why we’ve went into such great detail in this camera lens guide, so you have the knowledge you need to buy and use the right lenses for your shoots.

Many beginner photographers can be surprised to find that lenses become, by far, the most expensive accessory, often easily costing much more than the camera itself overall. This is easily explained. Firstly, to have enough versatility to capture a wide range of beautiful shots, you do need a few lenses. What you put on the front of your camera can drastically change the outcome of a photograph, so some are much more suited than others when it comes to a particular application.

Secondly, they are simply quite expensive to make in most cases. Modern lenses are packed with advanced optics, many glass elements, image stabilisation, auto-focus and other features which are all crammed into a plastic or metal cylinder. Whilst there are some incredibly cheap budget lenses out there which simply do the job of focusing the shot, most lenses are highly technologically advanced and thus take a long time to manufacturer.

Being such an important purchase, it’s critical that you understand the key features to look for, so without further ado, here’s our guide of what you need to know about camera lenses.

Camera lenses explained, the guide:


Budget

Firstly, you have to decide on your budget. With such a massive price range for camera lenses, from under £100 to over £5000, you might think that the cheaper options aren’t worth a look at, but this isn’t the case. Whilst medium-to-high range lenses will obviously give you the best quality images, the budget-friendly ranges can still produce great quality shots in a capable pair of hands.

The reason for some being so cheap is also because of a lack of advanced features. For example, the TOP-MAX range can still produce beautiful photographs for the price, but many of their lenses are manual focus only, so it needs a degree of skill to get a good shot.

All in all, simply budget what you can afford, and if you want to spend big on a particular lens, make sure it’s one you’re likely to use quite often so you get the best return on your investment.


Brand

The great think about camera lenses is that, whilst the main DSLR manufacturers produce their own lines, there are also a range of options from other manufacturers which have a solid reputation. Some of our favourite brands are:

  • Canon
  • Nikon
  • Tamron
  • Sigma
  • Fujifilm
  • Samyang
  • Sony
  • Olympus
  • Pentax
  • TOP-MAX

If you aren’t sure what to buy, then it’s a safe option to stick with a lens from your camera’s manufacturer, so if you have a Canon camera, buy a Canon-made lens. However, it’s certainly worth exploring some other brands as there are some great value options out there. For more information on the above, check out our guide on the best camera lens brands.


Camera lens types

This is certainly one of the most important decisions you will make. The type of lens dictates the entire outcome of a shot, which is why amateur and professional photographers alike usually have multiple lenses to attach to their camera when needed. Whilst some lenses are very versatile and will broadly cover a certain type of photography without any problems (i.e. portraits or landscapes), it can be useful to have some different options to expand your skill set.

Here’s an explanation of the main types of camera lens to watch out for:

Macro – these lenses are suitable for extreme close-ups usually on very small subjects. For example, an insect on a leaf. It usually has a very low depth of field for this style of photography, so whilst it’s specialised for those close-ups, it isn’t very useful for much else. That being said, macro photography can be simply beautiful and offers a completely different contrast to styles such as landscapes or portraits, so it’s a useful addition to any photographer’s kit.

Some top choices for Canon camera include this Canon EF 100 mm f/2.8 Macro USM, whilst for Nikon, take a look at the Tamron SP AF 90mm F/2.8 Di Macro 1:1.

Zoom – Zoom lenses, as the name implies, offer the ability to zoom in on through a focal length range. These are quite versatile, as they can be zoomed out for wider-angle landscape shots, but also zoomed right in to focus on specific subjects further afield.

Some best buys include this Canon EF-S 55-250 mm f/4-5.6 IS STM for Canon cameras, and this Nikon AF-S DX Nikkor 55-300mm f/4.5-5.6G VR for Nikons.

Prime – A prime lens has a fixed focal length, making each one suitable for a particular type of photograph.

Portrait – These lenses are perfect for portrait shots where you have someone near to you who you would like to photograph. The low aperture also makes it easier to create what’s known as ‘bokeh’ where the subject is sharp in focus whilst the background is blurred for a beautiful effect. For Canon, this Canon EF 50 mm 1.8 STM is one of the most popular out there, whilst for Nikon, the Nikon AF-S Nikkor 50mm f/1.8G is a gem.

Wide-angle – Wide angle lenses are perfect for landscape shots, as they can capture expansive scenes with a field of view often larger than the human eye. If you have a Canon camera, the Canon 9519B005AA EF-S 10-18mm f/4.5-5.6 IS STM has a quality to price balance which can’t be beat. For Nikon cameras, check out the superb Samyang AE 14mm f / 2.8 ED IF UMC.

Fisheye – This type of lens has an ultra-wide field of view, with a visual distortion to give a convex appearance to the image – a bit like the eyesight of a fish (hence the name). When used correctly, these lenses can provide a beautiful characteristic look to any photograph. This Opteka 6.5mm f/3.5 HD Aspherical Fisheye is ideal for Canon and Nikon DSLRs.


Aperture explained

To put it simply, the aperture is a bit like the pupil in your eye. The larger the aperture, the bigger the ‘pupil’ is, and the more light which reaches the camera sensor. With lower apertures, the pupil is small, so less light is allowed in.

You might ask yourself “well isn’t it better to have as much light as possible?”. When low lighting conditions are a factor, yes. However, aperture has a key role in setting the depth of field, which is the amount of the scene which is in focus.

A smaller aperture, for example, allows more background foreground elements to be in focus. A larger aperture will isolate a specific subject and bring it in focus whilst leaving the background blurred, which is a nice effect in portrait shots, for example.

HOWEVER, always remember that the aperture numbers (signalled by an “f/”) are in reverse, so the smaller number is a larger aperture, and a bigger number is a smaller aperture. Confusing, I know, but it’s best to remember it as this:

Smaller f/ number = narrow depth of field for more isolation
Larger f/ number = larger depth of field to bring more of the whole scene in focus


Focal length explained

Focal length is the maximum distance between the lens and the image sensor. This has some important implications when it comes to angle of view, as the longer the focal length is, the narrower the angle of view will be (how much of the scene is captured), but the higher the magnification. This is a trade-off when it comes to lenses, as higher magnification reduces the angle of view available.

Check out some of these examples:

Opteka 650-2600mm High Definition Telephoto Lens650-2600mm. The high 2600mm signals an extensive zoom range, but the 650mm will naturally limit the angle of view, meaning this is only suitable for zoomed shots. That’s why it’s a telephoto lens.

Samyang AE 14mm f / 2.8 ED IF UMC 14mm. This signals limited ability to zoom but a very large angle of view, hence why it’s a wide-angle lens!

In short:

Lower numbers = lower magnification, larger angle of view

Higher numbers = higher magnification, narrower angle of view

The range = The difference between the two numbers is the range you can work within. A larger range is more versatile.


Material

Whilst some lenses are made out of metal, most of them, even the most expensive, are made out of durable plastic. Why? Because they’re lighter. Particularly large lenses can be quite heavy, so during a day of shooting, they may become quite difficult to continue holding in a comfortable position. All good quality lenses still feel very firm and rugged, but by making them lightweight, they’re easier to use on a camera and easier to carry around (especially if you have a bag full of them).

However, most good lenses still have a metal ring connector at the base of the lens to ensure a tight and seamless fit without any wobble.


Lens optics

What about the lens itself? Simply put, the quality of the glass does play a role in the final result of the shot. Most lenses from reputable brands in the low-to-medium price ranges do have good enough optics for a great quality shots, but the much more expensive lenses are often where the truly world-class optics come into play.

A lot of lens optics now have modern features to help photographers. For example, there are lenses with low dispersion glass which reduces the amount the colours are spread out (hence reducing an unwanted colour distortion known as chromatic aberration).

Many Canon’s also have Super Spectra Coatings which reduce the slight degree of reflection caused by natural glass which can result in ghosting and flare distortions. Nikon has something similar with its Super Integrated Coating.


Manual focus vs autofocus

Manual focus is where you must adjust the lens itself to focus in on a specific subject in the scene. Autofocus does this automatically for you with small in-built motors. The vast majority of good lenses have this feature nowadays, and also provide the ability to turn it off if you would like more control.

For the most part, autofocus will serve you will in virtually every type of photography application. However, there may be times you prefer to do it manually. For example, in low-light conditions without much contrast, autofocus may spend a lot of time “searching” for the correct focus. Similarly, with macro photography, even the slightest disturbance to the scene can cause the lens to start re-focusing, so manual may be your best bet.


Image stabilisation

Some lenses, usually with a slightly higher price-tag, come with image stabilisation (IS) built into the lens. This reduces or eliminates the effect of camera shakes and vibrations (which are always occurring very subtly when the camera is being held in the hand).

So why is this so important? Well firstly, it considerably reduces the risk of blur in any situation. However, it’s particularly useful when it comes to slowing down shutter speeds (which is the length of time the sensor is exposed to the light through the lens). By lowering the shutter speed, more light can be captured which brightens up images even in low-light conditions, but the problem is this causes any slight vibration or movement to be captured as well, which blurs the image.

Image stabilisation reduces this from happening, so you can bring shutter speeds much lower to capture more light without risking any blur. Without that, photographs in low-light conditions can usually only be done with a tripod where the camera is kept perfectly still.

However, many DSLRs out there do come with image stabilisation built into the camera itself (where the sensor adjusts itself as opposed to the optics), so be sure to check this first.

There also may be some scenarios where you would prefer to turn IS off, as it can consume a lot of battery power. For example, if you’re using a tripod or you’re in a scene with a lot of light (and thus only need a faster shutter speed), IS probably isn’t required.

For more information about this, check out our guide: should I get a camera lens with image stabilisation?


We hope you’ve found this guide to camera lenses explained useful. If you’re interested in buying a new addition to your kit, why not check out our Canon lens reviews and Nikon lens reviews?

If you’re just starting out, also be sure to take a look at our camera lens tips for beginners for some essential photography lens advice you need to know.