[Sigma Blog] What is a Zoom Lens? And why and when to choose a Zoom Lens?
Take a look at this article about Zoom Lens from Sigma Blog!
Zoom lens are available at our store.
What is a zoom lens?
A zoom lens is a type of camera lens that is offers the photographer a useful range of different focal lengths in a single lens. This is in comparison to a prime lens, which only offers a single focal length. A zoom lens allows for quick and easy re-framing of a scene while staying in the same physical position. Sigma offers a line of over 20 zoom lenses for DSLR photographers, ranging from wide angle zoom lenses, supertelephoto zoom lenses, andhigh-zoom ratio all-in-one lenses for both full-frame (DG) and APS-C (DC) digital cameras.
Sigma offers a great variety of zoom lenses. (Lenses are not shown to scale in this display.)
Which Sigma zoom lenses are right for you depends on your photographic intentions, budgets, and overall size constraints. In this article, we are going to explore many facets of zoom lenses for digital photography and explain the terminology, key features and benefits of the different types of zoom lens. We’re also going to showcase images made with a variety of Sigma zoom lenses to illustrate key concepts.
Zoom Ratio, and Constant-Aperture or Variable-Aperture Zoom lenses
Zoom lenses always feature two focal lengths in the name which indicate the shortest and longest focal lengths in relation to the 35mm/full-frame sensor. To determine the overall zoom ratio of the lens, simply divide the longest focal length by the shortest. So, for example, the Sigma 18-35mm F1.8 DC HSM and the 8-16mm F3.5-4.5are both examples of 2x zoom lenses: 35 divided by 16 equals 1.95, and 16 divided by 8 equals 2. (It is common practice to round to the nearest whole number or major fraction.)
Fall leaves seen through the Sigma 18-35mm F1.8 DC HSM lens at 24mm. 1/400 F4.5 ISO 100 on a Canon EOS Rebel T3i.
To read the full article, please visit the original source here: http://blog.sigmaphoto.com/2014/what-is-a-zoom-lens/