A decentralized lens contains one or more elements of an optical lens that are either shifted or tilted from its main axis. Such a shift or tilt of the lens elements can potentially lead to blurring / softness of parts of the image due to the divergence of light rays. While in many lenses you can observe very slight decentration of the optical elements, especially on super zoom, strong decentration and tilt can make the whole image blurry, because the lens cannot achieve good sharpness over the entire frame.

It is always useful to check the lens before buying, even if it is brand new. Unfortunately, despite the efforts of manufacturers to manufacture each lens, many things may go wrong once you get your copy. In some cases, this is the manufacturer’s fault (poor quality guarantee / low standards), and in some cases it’s the fault of some guy who casually throws a box with a lens during transportation. Unfortunately, these conditions can negatively affect the operation of the lens and create all kinds of problems. Decentration of lens elements is one such problem, as photographer Nasim Mansurov talks about in a blog post. Continue reading →