Olympus M.Zuiko Digital ED 12-100mm F4.0 IS Pro
A longer maximum focal length allows you to focus in on a small part of a scene, and offers a narrower angle of view than shorter focal lengths.
Sigma 300-800mm F5.6 EX DG APO HSM
A shorter minimum focal length allows you to get more of the scene in the photo, and offers a wider angle of view than longer focal lengths.
Canon EF 35mm F/2 IS USM
Canon EF 400mm F/4 DO IS II USM
A normal lens is one that doesn't fall into another category such as wide angle or telephoto, and typically has a focal length between 35mm and 70mm. These lenses aren't tailored towards a specific type of photography, and so are quite versatile.
Optical image stabilization uses gyroscopic sensors to detect the vibrations of the camera. The lens adjusts the optical path accordingly, ensuring that any type of motion blur is corrected before the sensor captures the image.
The zoom range is the ratio between the longest and shortest focal lengths. A higher zoom range means that the lens is more versatile.
Tamron 18-400mm f/3.5-6.3 Di II VC HLD
A true macro lens has a magnification of 1:1. This means that the image produced is a life-size representation of the subject being photographed.
Leica Vario-Elmarit-SL 24-90mm F2.8-4 ASPH
With a wider aperture the sensor can capture more light, helping to avoid blur by enabling a faster shutter speed. It also provides a shallow depth of field, allowing you to blur the background to focus attention on the subject.
Samyang XP 50mm f/1.2
Similar to the number of aperture blades, rounded blades affect the way the light gets through to the sensor. Rounded blades, often only found on more expensive lenses, improve the appearance of the out-of-focus areas. This allows you to attain better, softer looking bokeh in your photos.
The aperture controls how much light gets through to the camera’s sensor. More blades is often an indicator of a better quality lens. It also allows you to achieve much nicer looking bokeh when blurring out your background, whereas a lens with less blades will often produce harsher, more polygonal bokeh.
Lensbaby Velvet 85
With full-time manual focus, you can move the focus ring whilst it is in AF (autofocus) mode. This means that you can make manual adjustments once the AF has finished, without changing to manual mode.
Lenses with a built-in focus motor can autofocus even if the camera does not have its own focus motor.
Many lenses allow you to focus to infinity. This is essential when you wish to take photos including far off objects, such as when shooting landscapes, in order to make sure everything is sharp and in focus.
This is the closest distance that the lens can focus. A shorter minimum focus distance allows you to get closer to your subject, and is particularly important when doing macro photography.
Zeiss Batis 40mm f/2 CF