In this guide we will go over what all the specifications mean to help you choose an appropriate optic for you!

We will be covering this from a photographers point of view and only touching lightly on each subject. Most photographers won't require this guide. It's aimed at new users who only have the basic kit lens and are looking for something better suited to what they shoot.

The camera lens is the most important part of your gear

It's what's really taking the photo. The camera records what the lens sees. Most of your image quality is coming from your lens, not your camera body.

Two lenses that seem superficially similar may vary greatly in price. For example the Canon EF 50mm f/1.2L USM retails at over 10x the price of Canon EF 50mm f/1.8 STM. Despite the similar focal length the former lens offers far superior optics resulting in less flare and better colour and contrast than similar lens, in addition to other features like weather-proofing and an 8-blade circular aperture for excellent out-of-focus blur. With the extra cost also comes increased size and weight.

We will break it down further below.

For this example I'll use the Nikon AF-S 24-85MM F3.5-4.5G ED VR

Nikon

This is the brand that makes the lens. A Nikon lens will only fit onto Nikon bodies, the same applies to Canon. Tamron and Sigma are 3rd party manufacturers and will produce versions of lens for all kinds of different cameras. Most camera manufacturers only make lenses for their own systems.

Nikkor

Since many of these camera brands are very old, they still label lenses with things like Nikkor or Fujinon. You can generally ignore this. As long as your mount is correct it's going to work.

AF-S

This is the auto focus system. They come in lots of different types from Canon's USM to Nikon's new AF-P system (not all nikon cameras work with AF-P). If your seeing something like this in the title, it has auto focus. Some manufacturers don't list this anymore in the title so if unsure, read the full specifications of your lens or ask us.

F3.5-4.5

This is the aperture. The f stands for focal length and the number following is a fraction of the focal length. This is why often - but not always in this case - the focal length is denoted with 'f/' e.g. f/1.2.

Aperture controls the amount of light reaching the camera sensor. The bigger the "hole" the more light hitting the sensor. It is also influences depth of field to a degree. Higher numbers make the aperture rings go smaller, keeping more of the scene in focus.

Note that if there is a hyphen ("-") in the aperture, it makes it changes as it zooms. It gets darker as the focal goes up. It's possible to buy lenses now that don't change aperture as the focal changes though they are physically larger and more expensive. If you're into video it's very helpful.

ED

This is the type of glass used. Not all brands will mention it.

VR

This is also quite important for longer focal lengths. It stands for vibration reduction and helps counter hand shake allowing for a sharp result with a slower shutter speed. If you only use your lens on a tripod, you don't need this. Also, some cameras now like Olympus's mirrorless models have vibration reduction built into the camera, meaning that every lens attached will have some form of stabilisation.

Other brands use a different mark to display if the lens has vibration reduction. Tamron uses VC and Canon uses IS.