Digital Camera Lens Buying Guide - 2019

15/03/2019 12:30 PM

The world of interchangeable lenses is exciting for anyone to enter, with its seemingly endless options of equipment to choose from. One of the most important purchase decisions you will make, and perhaps one of the most confusing for beginners is that of the lens.

Hopefully, with a little guidance and a quick briefing on some key terms, we can make your next lens purchase as stress-free and enjoyable as this hobby called photography should be.

Basic Lens Buying Guide

First things first - will this lens fit my camera?

So you have this new camera which you love so dearly and you are starting to develop a love for a specific type of photography - that might be macro, landscape etc. Before we get into the advice section, you need to have an understanding of which lenses are compatible with your camera. For some brands it is simple, for others it will take a little bit of understanding on your part.

Brands such as Canon and Nikon have a few different lens mounts, including their DSLR and mirrorless offerings. Within these mounts, there are sometimes certain lenses which are only compatible with certain models (Full-Frame or Crop Sensor).

Other Brands such as Panasonic and Olympus currently only have their Micro Four Thirds system, and all MFT lenses will be suitable.

Manufacturers provide this essential compatibility information with a selection of letters or acronyms, which we will attempt to make clear below.

Lens Mounts

The lens mount is the most basic piece of information that you must be aware of when buying a new lens for your camera. With the exception of Panasonic and Olympus and their Four Thirds and MFT mount, lenses from one mount cannot physically be mounted directly onto a camera with a different mount.

Below is a list of all lens mounts that we stock cameras and lenses for, or we have at least stocked over the last few years.

Basic Lens Buying Guide

Full frame or crop sensor?

Manufacturers will display the following acronyms to describe if a lens is designed for use on full frame or crop sensor models.

Digital SLR:

Basic Lens Buying Guide

Third Party Brands: 

Basic Lens Buying Guide

Note: For both Canon and Nikon, Full Frame lenses can be mounted on crop sensor cameras, but not conversely.


Basic Lens Buying Guide



Note: Sony Full Frame lenses can be mounted on crop sensor cameras, but not conversely.

Basic Lens Buying Guide
Basic Lens Buying Guide

What do all those other numbers and letters mean?

Now you have a basic understanding of which lenses will mount and function on your camera but how do you decipher all of the other jargon and choose which lens is the perfect fit for your style of shooting?

Focal Length

The Focal Length is the first number that is used in the name of a lens and it is used to describe the field of view that the lens will provide when mounted on your camera.

Zoom lenses will have two numbers, as the lens can zoom between two focal lengths using all fields of view in between (ie: 18-55mm or 70-300mm). Prime lenses offer no zoom and therefore are just given one number (ie: 35mm, or 50mm).

Lenses with a smaller number will offer you a wider field of view, while a larger number will mean a more magnified image.

Lenses of a certain focal length will be more useful for partaking in certain types of photography. Without confusing things too much, Crop Sensor cameras magnify lenses due to their smaller size, which is referred to as crop factor. For this reason, the same focal length will provide a different field of view when mounted on these cameras, compared to when mounted on a full frame camera.

Basic Lens Buying Guide


The aperture is usually the second number in the name of a lens, and it is otherwise referred to as an F-stop. This number tells you the maximum aperture of the lens, with this key specification reflecting how much light the lens is capable of gathering. Lenses with a larger maximum aperture let in more light, which is desired for shooting in low-light conditions. A larger aperture also allows for you to create shallower depths of field (ie. Less foreground in focus and greater blur in the background).

Now for the tricky part. A smaller number indicates a larger aperture. For example, an f1.4 lens is considered very fast and lets in plenty of light, whereas an f2.8 lens is a slower lens.

Zoom lenses sometimes feature a varying maximum aperture (ie. Nikon AF-S 18-55mm f3.5-5.6).

The maximum aperture of a lens can be displayed in various ways despite meaning the same thing. eg. f/1.4, F1.4, or 1:1.4.

Basic Lens Buying Guide

Image Stabilisation

In the digital age, Image Stabilisation has become a sought after feature in camera equipment, thanks to its ability to reduce the impact of camera shake. Some cameras have Image Stabilisation built-in, while in other instances you need to purchase a stabilised lens.

Different brands refer to their Image Stabilisation system in different ways, as per the table below. 

Basic Lens Buying Guide


With the exception of select offerings from a few high-end brands, most modern lenses will offer Autofocus of some type which will generally not cause any compatibility issues but will have a bearing of the performance of the lens and its suitability to certain types of photography.

The following are examples of acronyms that manufacturers use to describe the AF system of a lens.  

Basic Lens Buying Guide

Note: Certain entry-level Nikon DSLRs do not have built-in AF motors, so they rely on the built-in AF motor of a lens to provide you with autofocus. For these cameras, Nikon AF lenses will not autofocus but AF-S and AF-P lenses will. 



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