Description: the different color channels show different distortion patterns. Usually this leads to outlining on edges of high contrast that gets stronger the farther you move away from the center.

Aberration opticalmeaning

Solution: “uniform” barrel or pincushion distortion can be easily corrected. For complex/wavy distortion though, lens correction profiles are mandatory, but not every correction profile works perfectly at every focusing distance. You can also have a look at this article to find out how to create your own correction profiles for Lightroom/Photoshop.

Description: Longitudinal chromatic aberrations come in different forms where the most common are purple fringing (it shows up close to the plane in focus) and the “bokeh-CA” or “bokeh fringing” which you will see in the out of focus areas.

Aberration opticalchromatic

Thanks for the overview, but I think you might have mixed up LoCA and LaCA: https://www.image-engineering.de/library/technotes/750-longitudinal-and-lateral-chromatic-aberration

Trivia: for portraits a bit of undercorrected spherical aberration can be beneficial to give a smoother more flattering look

I have paid careful attention over the years to reviews like those you post to ensure that I avoid lenses that have built in problems that are difficult to correct (LOCA, a tendency to veiling flare and reflections, field curvature).

Solution: stopping the lens down will reduce this. You can also try to correct it in post, but this will not always work well enough.

Reg. b.: that would be a lengthy article 🙂 But I will use the opportunity to point out 2 resources I personally find reliable and often use as a reference/to double check my findings: Lenstip and Cameralabs.

Solution: none (except for maybe buying a lens where this is less pronounced) Stopping down you will eventually get a perfect circle at some point, but then you are shooting at e.g. f/2.8 instead of f/1.4.

Solution: stopping down will usually reduce the field curvature. With some lenses focusing on the midframe instead of the center can also improve results.

Aberration opticalexamples

Description: the shape of out of focus light circles deteoriates towards the corners of the frame, so instead of circles you see shapes that resemble cat’s eyes.

Trivia: this is not exactly a lens aberration but rather the inability of digital sensors to capture light that hits them at a very acute angle.

Trivia: Some lenses that carry an “APO”-tag are perfectly corrected for this aberration and won’t show any colorful outlining at all.

a. I would like to add mine to all previous expressions of gratitude to you all. This and FM are reliably and always the 2 most interesting photo-related sites in all of history. Thank you!

That was one of the main reasons to put it together: to have an easy to understand resource that can be linked to to clear up confusion 😊 Title picture has been taken with the Jupiter-3 50mm 1.5 @ f/1.5. I think every aberration is there 🤣

Types ofaberrationin optics

I always though that Color cast comes from coatings of the lens. And one of the quickest ways to fix it is shifting WB setting.

Trivia: when taking a picture of a uniform yet structured surface you can use the “find edges” filter in Photoshop to make the shape of the field curvature visible.

Solution: first stop the lens down and then focus. Often it also helps to just use f/8.0 to f/11 for this not to be a problem anymore.

Clear, easy-to-digest article, should clear up a few users’ misunderstandings. I like that first photo of the pinetreeling and the lit funky bokeh behind it. Looks pretty stellar, like the MC 28/2’s : )

• Most of the aberrations (CA, astigmatism, coma, vignetting) are often non-uniform and greatly increase towards the corners. At least for web sized pics cropped (relative to lens image circle) sensors might care less. • Color cast can cover the whole frame. I think several people on the team have Canon FDn 50/1.4 which wide open often gives uniform purple cast over the whole frame. I think the physics behind it is different from the corner cast, but it is still a thing. • Veiling flare for adapted lenses depends on adapter and sensor behind the lens.

Astigmatismaberration

One of the most common aberrations that help with is the “finger oil” on lenses. Especially for cellphones or small diameter lenses. The images are less sharp especially with incoming light source (at night). That’s easy to fix by wiping the smudges from the lens.

So is the article wrong? Or am I misunderstanding it? Under LaCA: “This kind of aberration does not lead to colored areas, but to fringes that occur around objects of high contrast as the magnification is dependent on the wavelength.”

Trivia: on digital sensors some lenses (especially those with a small rear element close to the sensor) show increased light fall off due to “pixel vignetting” caused by the light rays hitting the sensor at an acute angle.

If you compare the tree image under LoCA and the test chart image under LaCA, you can see that both types of CA can look similar. Maybe that’s why I was confused about it. The only way to find out, which CA is present, is to stop down, because LaCA will stay.

Solution: correct it with the third party software “corner fix” or use flat field correction/gradients in Lightroom, for more details have a look at this article

Chromaticaberration

It is competent and light and okay with my A7R2, but the onion rings grate (and the bokeh, while generally pleasing, is often busy.

Solution: with most lenses stopping down will reduce the light falloff (with very small lenses there are sometimes only minor improvements) Corner exposure can be lifted in post processing e.g. in Lightroom. For common lenses there are profiles available. Correcting this in post can lead to increased noise in the corners!

Description: When you shoot a flat scene there is a dip in resolution/contrast in a part of the frame, e.g. the midframe area or the corners. In the example above you can see a lens that has higher corner resolution than midframe resolution.

I missed one…, Sunstars. .., you like them very much, but they are not what I see bare eyes, so for me its an aberration.

Really appreciate this article. It clarifies a lot of things that I see in my Takumars and other film-era lenses and makes it clear what can be corrected for and what we just have to live with. Looking forward to a follow-up article or two.

I can appreciate the work on explaining. I am optical engineer myself and I tend to explain such concepts from time to time . Well put together, and pretty complete collection!

Indeed that is a major issue with smartphone lenses, it may also lead to a plethora of lens flares. For foggy/hazy lenes I would like to have 2 perfect examples lenses: one with and one without. Unfortunately this is not the case so far. It might also better fit a “common issues in used lenses” articles, together with loose mechanics and too slow aperture blades.

I especially like the Zeiss Batis 135mm in particular, though I like the Sony 28mm f/2 as well. I that I had been more savvy before buying the 55mm f/1.8, though (I failed to read your review in that instance).

If the image circle of the lens is big enough (as in: uneconomically big) there are no cat’s eyes, so claiming this is unavoidable is simply wrong. Or to make it more simple: your toilet roll just needs a bigger diameter. As I have shown there are big differences between lenses with arguably the same specs. Probably that is the reason people are interested about these differences.

Description: undercorrection: loss of contrast and resolution (“glow”) across the whole frame overcorrection: harsh bokeh with severe outlining

Solution: in most cases this can be losslessly corrected in post. Stopping down does not make a difference to this aberration.

Well done, especially your example pics. Having participated in the development of lenses myself and also measuring them in Ulbricht-Spheres I would add two things: – Vignetting is unavoidable with all lenses and is ruled by the cos4 law! – ‚cats eyes’ is also unavoidable and can be comprehended simply by looking through a toilet roll and moving it parallel of axis from your vision. I will never understand why people keep ranting over these things in all of the lens reviews?!

great overview! Not really worth including because its proabably very rare, even in old glass, is hotspots. Both the Canon FD 17mm f4 and 20mm f2.8 often show a hotspot in the middle in high cotrast situations, which is annyoing very hard to correct. https://www.flickr.com/photos/96189377@N08/16656221562

There are some interesting lenses like the Nikon AF-S 24-120mm f/4.0 where the laCA do interesting things and seem to also be lower when stopping down. But those are a really rare exception.

Yes it is about optics, but it shows a lot about optical design and optimize for abberations. Optical designers should also be rewarded to get a good corrected lens with as little as possible lens-elements and a design that is less vulnerable to fabrication errors depending the specific goal of a lens. Sounds strange but a simple 5 element Ernostar design with one ED element performes great as an astrolens when stopped down a third of a stop, the Nikkor AIS ED 180mm f2,8. Yep wide-angles are more difficult… a flexy curved sensor will help optimizing lenses, costs and element.

Description: small point light sources in the corners of the frame are not rendered as points but take on weird shapes instead.

Sphericalaberration

Also, the lenses with old designs usually have this color cast issue, because those designs were developed for film cameras, so glass coatings were different. Most of the time you will see harsh yellow/green color cast, compared to the modern lenses. I do believe that the glass elements with different coatings are at fault here.

Aberration opticallenses

indeed lenses could be blocking some of the colors also there is sensor/processor programming and it also effects the colors greatly, so if the lens is different the sensor gets different amounts of different colors, there fore sending different kind of information to the processor and processor makes the image according to the information that it got, the sequence is something like that. Depending on how it is programmed and how it “understands” the colors we get the results, that`s why modern lenses got the “color profiles” even in cameras so the images looks stunning with proper contrast, colors and clarity, but if we could adapt them to the early cameras that can not understand those color profiles, I wonder how the images would look on them 🙂

A nice roundup, thank you! Noted that different color renderings are not included in the list. I don’t see that as a serious omission though. There is no disagreement about some lenses producing warmer colors than some others. Sometimes however there are strong opinions about the color characteristics of a specific lens, but I think those are mostly subjective opinions without rigorous research. Scientifically thinking, it can be assumed that different glass types can act as filters, blocking certain wavelengths more than others. But I don’t know how the lens could change the wavelengths of the light going through it. The colors in an images are the result of a complex phenomenon that depends on many things, including the spectrum of the light, the reflective spectrum of the object, and the sensor. So, a few sample photos really can’t tell everything about how a lens handles colors.

In many of our lens reviews we talk about certain kinds of aberrations, so this article shall give you an overview of typical lens aberrations, tell you in what lenses to encounter them and how to cope with them. Last Update: January 2023

The color cast you are talking about is visible across the whole frame, not only in the corners. Often (but not always) Auto White Balance will already take care of this.