• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Home
  • News
  • Reviews
  • Organizing
  • Editing
  • Explainers
  • Photo-editing A-Z
  • About

Life after Photoshop

  • Lightroom Classic
  • Capture One
  • Nik Collection
    • Analog Efex
    • Color Efex
    • Silver Efex
    • HDR Efex
    • Viveza
    • Sharpener
    • Dfine
    • Perspective Efex (retired)
  • DxO PureRAW
  • ON1 Photo RAW
  • Exposure X

Lens aberrations and what you can do about them

May 26, 2020 by Life after Photoshop

Photo by Phil Hearing on Unsplash

Aberrations, or optical imperfections, exist because no lens is optically perfect. In the ideal world, every lens would produce a sharp, undistorted, evenly illuminated image that’s sharp from edge to edge. Some lenses come close, but the fact is that lens designers have to work within the limitations of the laws of physics and the glass materials they have available, and almost all lenses have some or all of the following aberrations from the ‘perfect’ image.

  • Distortion
  • Chromatic aberration
  • Vignetting
  • Diffraction
  • Lens corrections

Distortion

Distortion is where lines which should be straight appear slightly bowed. This effect grows stronger near the edges of the frame. Wideangle lenses tend to suffer from barrel distortion, where straight lines appear to bulge outwards – especially zoom lenses at the wide-angle end of their zoom range.

Telephoto lenses (especially telephoto zooms) often suffer from the opposite effect, pincushion distortion, where straight lines near the edge of the picture appear to bend inwards.

Zoom lenses suffer more from distortion than fixed focal length prime lenses because the lens designers are having to deal with a much more complex set of optical elements and have to choose compromises between optical performance, size and weight, price, zoom range and more. It’s possible to apply very effective distortion correction using software.

Chromatic aberration

Chromatic aberration is a very common aberration. It shows up as colored fringes around the edges of objects and becomes more noticeable away from the center of the picture.

Lateral chromatic aberration is the most common type, producing relatively narrow but quite prominent magenta, blue or green edge ‘halos’ around objects. Axial chromatic aberration is also quite common but less noticeable. This produces soft colored ‘halos’ around out of focus objects. It can show up if you use long focal length lenses and shallow depth of field for strong background blur. This can not easily be fixed in software and has can only be corrected effectively by advanced optical designs.

Vignetting

Vignetting is sometimes called ‘corner shading’, and it’s where the edges or corners of the image are darker than the centre. There is a tendency for this to happen with simple lenses so it’s the lens designer’s job to counteract this with the lens design.

Even so, many lenses exhibit some vignetting. It doesn’t always harm. The composition and can sometimes help focus attention on your main subject. Vignetting tends to be worse with cheaper lenses at or near their maximum aperture settings.

Diffraction

Diffraction is sometimes treated as a lens aberration, but it’s not quite the same as the others. Light is diffracted (bent) when it passes the edge of the diaphragm blades in the lens’s aperture mechanism, and at very small lens apertures a greater proportion of the light is diffracted, which leads to a drop in resolution. Generally, this effect becomes noticeable from lens apertures of f/11 and smaller – though it starts earlier with smaller format cameras because the lenses and apertures are physically smaller.

Some camera makers attempt to correct this softening effect. Fujifilm has an LMO (Lens Modulation Optimizer) feature which digitally corrects this diffraction softening.

Lens corrections

It is possible to correct many aberrations with a suitable lens design, but often not all of them, especially when customers also want long zoom ranges, wide apertures, light weight and low cost. As a result, lens design is usually a set of compromises and no lens is ‘perfect’. It often comes down to cost. Good optical performance is not difficult to achieve, but achieving excellent optical performance quickly becomes expensive.

Increasingly, lens makers and photographers are turning to digital lens corrections. Lens correction profiles may be applied automatically in-camera as the image is processed, embedded in RAW files for use by RAW conversion software, or applied automatically by software by matching the lens uses against a database of correction profiles.

This has become a cost-effective way to correct common lens aberrations and successfully eliminate distortion, chromatic aberration and vignetting to a degree that would be impossible or just too expensive with advanced optical lens designs.

Related

Filed Under: General, Photography explained

Life after Photoshop is owned and run by photographer and journalist Rod Lawton. Rod has been a photography journalist for nearly 40 years, starting out in film (obviously) but then migrating to digital. He has worked as a freelance journalist, technique editor and channel editor, and is now Group Reviews Editor on Digital Camera World. Life after Photoshop is a personal project started in 2013.

Primary Sidebar

Subscribe to this site

Enter your email address to subscribe to Life after Photoshop and receive notifications of new posts by email.

Adobe Lightroom: what is it, where do you get it, what does it cost in 2025?

Adobe Lightroom is not one program but three. You could … [Read More...] about Adobe Lightroom: what is it, where do you get it, what does it cost in 2025?

The best photo editing software for organizing, editing, RAW and effects

Choosing the best image editing software used to be easy. … [Read More...] about The best photo editing software for organizing, editing, RAW and effects

Layers explained

Layers explained: what they do and how to use them

Layers are a central part of many photo editing processes, … [Read More...] about Layers explained: what they do and how to use them

BAN adjustments… Basic And Necessary image corrections to do first

Photo editing software does two quite different jobs. It can … [Read More...] about BAN adjustments… Basic And Necessary image corrections to do first

More Posts from this Category

Mission statement

Life after Photoshop is not anti-Photoshop or anti-subscriptions. It exists to showcase the many Photoshop alternatives that do more, go further, or offer more creative inspiration to photographers.

Affiliate links

Life after Photoshop is funded by affiliate links and may be paid a commission for downloads. This does not affect the price you pay, the ratings in reviews or the software selected for review.

Contact

Email lifeafterphotoshop@gmail.com

Copyright © 2025 Life after Photoshop · News Pro on Genesis Framework · WordPress · Log in

We use cookies to ensure that we give you the best experience on our website. If you continue to use this site we will assume that you are happy with it.OK