Talk:Optical aberration

Expert offer

I have been a professional in this area for over 30 years, and would be happy to take this on if there is no-one else willing. As I have only just joined Wikipedia, I will need some time to get used to it. My first reaction from looking at the current article is that it does need comprehensive rewriting although parts of it can be reused. LarryJayCee 22:54, 25 February 2007 (UTC)

Welcome to it. Ask here if you need help figuring out how to do things wiki-style, or whatever, and some of us will be glad to help, I'm sure. Dicklyon 23:17, 25 February 2007 (UTC)

Please Larry - fill yer boots! This is, as it stands, a truly bad article because it was lazily grafted here without any thought of context. Having tried to read it myself, I would recommend starting from scratch. Please contact me if I can help with any subsections or in any other way.Rbowman (talk) 14:48, 27 February 2008 (UTC)

One change I recommend in the rewrite: since many of the Seidel aberrations have individual articles, this article should summarize them, but reserve the details for the individual articles. Instead, this article should focus on the big picture, going into detail on topics not covered by other articles. I can help with formatting and Wikification, but am not an expert in this area.--Srleffler (talk) 18:54, 27 February 2008 (UTC)

Expert required

This page is almost completely lifted from Project Gutenberg. Because Gutenberg is public domain, this is not a copyright problem, but the original text dates to 1911, without changes. An expert is needed to check the current accuracy of the article.

Catfood73 13:53, 22 January 2007 (UTC)

General

This is good stuff, but needs cleaning up.

Does anyvone have the images that belong to this article?

User:Egil

I have obtained a copy of the original (with diagrams), and I suppose I could re-draw them, they're not too complicated. OTOH, I really dislike the style of this article; I'm thinking your idea of splitting off the aberration section of lens is a good one, and expanding that to replace this article. -- DrBob 22:50 Jan 29, 2003 (UTC)

Just scanning them would be much better than nothing.

I've added the question wrt missing illustrations to Wikipedia:Pages needing attention. Please delete the entry there when this is fixed. Egil 22:52 Apr 24, 2003 (UTC)

I've added the scans from the original article. Not good quality, but if and when someone re-writes this, they should come in useful. -- DrBob 21:21, 15 Mar 2004 (UTC)

filter into separate articles?

There are already specific articles on some types of aberations, such as Coma and Spherical. Maybe this should be more of a summary, and the info used to supplement/enhance their repsective articles. Tenfour 20:51, 15 February 2006 (UTC)

I agree. The individual articles need to be improved/cleaned up, and then this article needs to be edited to provide a good summary and overview. There is a lot of material that will probably remain here, however. Many aspects of aberrations are best treated together.--Srleffler 07:03, 30 March 2006 (UTC)

Overwhelming?

This page, at first glance, is a bit much. It really has a great deal of content, but it is so heavy that it is nearly unreadable.RSido 04:41, 2 January 2007 (UTC)

Pencils?

An 1851 explanation of pencils of light

I have never seen the word Pencils used in the context that is is on this page. Sometimes i think that it means angles and sometimes i have no idea what it is referring to. Is this how the original (Gutenburg) article is written or is this a vandalism of sorts? -- Straha_206th 18:19, 9 February 2007 (UTC)

See if this book page helps: Dicklyon 00:55, 10 February 2007 (UTC)

Requested move

The following discussion is an archived discussion of the proposal. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the proposal was move. Duja► 08:32, 23 October 2007 (UTC)

---

Aberration in optical systems → Optical aberration — This would be a simpler, clearer title, and would reduce the need to pipe links to this article. Another posibility might be Aberration (optics). —Srleffler 16:42, 18 October 2007 (UTC)

Survey

Feel free to state your position on the renaming proposal by beginning a new line in this section with *'''Support''' or *'''Oppose''', then sign your comment with ~~~~. Since polling is not a substitute for discussion, please explain your reasons, taking into account Wikipedia's naming conventions.

• Support - either optical aberration or aberation (optics) would be an improvement. Dicklyon 20:18, 18 October 2007 (UTC)
• Support "Optical aberration" is more concise and more search friendly--victor falk 23:56, 18 October 2007 (UTC)

Discussion

Any additional comments:

The above discussion is preserved as an archive of the proposal. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

wrong drawing

The drawing 386px-ABERR4.svg is not correct. The radial distortion inreases or decreases with the the distance to the centre of distortion. If it decreases the result is a barrel. So the distorted barrel have to be smaller than the object. Someone with the privileges could change it. --Msoon1509 (talk) 12:14, 17 May 2009 (UTC)

Zernike fitting?

The article discusses fitting a wavefront with a Zernike polynomial. This sort of makes sense, but I'm not clear on how the wavefront would be described. Ideally, a wavefront converging on the image surface would be spherical so that it comes to a point on the image surface. Is the idea that you compute that nearly-spherical wavefront in spherical coordinates? That is, do you look at the chief ray 1mm away from the image and then normalize the rest of the wavefront with ρ in [0,1] representing the angles from the center to the edge of the exit pupil as seen from the image point, so then you ideally would have

$r(\rho ,\varphi )=1\,\mathrm {mm}$

(a section of a perfect sphere) and so the aberration is the error,

$\mathrm {aberration} (\rho ,\varphi )=r(\rho ,\varphi )-1\,\mathrm {mm}$.

Is that basically right, or is it something else? I ask because my understanding is that the DC Zernike term corresponds to Piston (optics) and that page does an awful job explaining. If what I describe is correct, then the DC Zernike term is just defocus, no? —Ben FrantzDale (talk) 12:30, 30 May 2012 (UTC)

Basic problems

The problems begin right at the start and are not just technical.

"An optical aberration is a departure of the performance of an optical system from the predictions of paraxial optics.[1] In an imaging system".

To my mind, this is a muddled and inadequate definition. For example, camera lenses designed using optical models much more sophisticated than paraxial optics still exhibit aberrations (departures from ideal performance).

As another, hardly technical, mistake, the author seems to think that the retina of the human eye is a plane surface. A medic will correct me if I'm wrong, but I think that this is horse feathers!

I'm not sure that the article belongs under medical stuff either. Lens aberration is a general topic of interest to those in various fields and is certainly not limited to optical lenses. Much of the analysis applies to radio frequency (RF), particularly microwave, lenses in radio astronomy.

NetherWyndham (talk) 07:24, 17 October 2015 (UTC)

The definition is correct as written. Aberrations are by definition the departure in performance of an optical system from the idealized paraxial model. Camera lenses are designed using sophisticated ray tracing to minimize aberrations, i.e. to obtain performance closer to the ideal, paraxial model. Some aberrations remain in even the best designs.

Yes, the retina is not a plane. I fixed that. A large part of this article (including the section that claimed the retina is a plane) was pulled from the 1911 Encyclopædia Britannica. It's way overdue for a rewrite. If nothing else, the writing style is antiquated.

I'm not sure what you're getting at with "...belongs under medical stuff".--Srleffler (talk) 07:48, 17 October 2015 (UTC)

"The definition is correct as written." That's missing the point. The question to be addressed is whether the definition is clear and understandable to a person not already familiar with the subject. Geoffrey.landis (talk) 19:34, 22 September 2017 (UTC)

I'm not sure how to make it any clearer. Do you have any suggestions?--Srleffler (talk) 05:05, 23 September 2017 (UTC)

Right now my best suggestion is to delete and rewrite from scratch, but absent that, I rewrote the first paragraph incorporating a definition from a standard physics book, and, I hope, aiming the lede a little more on the main aspect of abberation. Geoffrey.landis (talk) 13:26, 25 September 2017 (UTC)

EB1911 sourcing

Almost the entire article, except for three or four added paragraphs, is an exact copy of the entry in the Encyclopædia Britannica Eleventh Edition. I was going to add footnotes to each EB1911 paragraph, but that seems excessive (it came out to about 35 footnotes). If this article ever gets more of a rewrite, and needs some specific footnotes for the surviving EB1911 material, it can be compared with s:1911 Encyclopædia Britannica/Aberration, using Earwig's copyvio detector for example. David Brooks (talk) 19:57, 3 May 2016 (UTC)

Any good article starts with a first structure of the contents, let's do it!

As explained, this article was adapted from an old article with no copyright problem. I am not an expert in this subject. I just have a general knowledge from what I have read in photography books. There is an old offer from an expert, I ignore what inhibited him for rewriting the article. I hope that he had not been disappointed by the stupid robots that blindly revert changes based on a weak criterium which considers everything vandalism. Nor by those kids which spend too much time editing earning the rights to control Wikipedia, but lacking experience want to blindly apply rigid rules based on what they subjectively believe is the correct thing. That is the reason that inhibited me to write in subjects that I know.

For those enthusiasts who want to improve this entry, I suggest to propose a new structure.

From my limited point of view, I think that a good start is to explain an ideal optical model, which anyone that learned Analytical Geometry in school, can understand. Then introduce the limitations to build the lenses that we know, explaining what aberrations are caused from the elements available to build lenses. How those aberrations are solved, for example by composing lenses in groups, adding anti-reflexive coatings, etc. Then moving to the optics of other spectrum of the electromagnetic space, like that in radio-astronomy, radars, medical imaging equipment, different kinds of microscopes, etc.

In synthesis, first giving a general overview of optics with parabolas, spheres modelling elements like mirrors and glasses, then explaining why those models are difficult to implement in real lenses. And after explaining with objects which are familiar to almost everyone like, mirrors, eyeglasses, magnifying glasses, Fresnel screens, camera lenses, microscopes, telescopes, etc. Going to radio-telescopes, electron microscopes, radars, medical imaging systems like ultrasound, tomographies, etc. — Preceding unsigned comment added by 201.124.237.242 (talk) 00:22, 24 December 2019 (UTC)

I reverted the changes you made. The core problem was that you assumed that a parabolic-shaped lens would produce an optimum focus, which isn't true. Parabolas are optimum for mirrors, not lenses. There were other problems, and not much to be gained by trying to keep anything from that edit.

Our goal in writing articles is for all the important information to be verifiable by consulting reliable, published sources. It's OK to rely on your memory of things you've read (at least for straightforward, noncontroversial facts), but you shouldn't be making stuff up yourself and putting it into Wikipedia, like the idea that a parabola would be the optimum shape for a lens.

Regarding the project proposed above: the introduction and "Overview" sections of the article are pretty good as they are. They don't come from the Encyclopædia Britannica. The problem referred to in the tag at the top of the article affects the rest of it, from "Theory of monochromatic aberration" on. I don't think trying to explain an "ideal optical model" first is going to work well. Optics is based on simplifications for a reason. A good explanation of why real lenses don't behave like the ideal would be useful, as would an explanation of how we deal with aberrations in practice. Some of that is already in the article, though.--Srleffler (talk) 01:33, 31 December 2019 (UTC)

Apologies in advance. Im not a wikipedian but I do hold a degree in this field. Replying to Srleffler, I hope you can make use of what im about to say whilst you search for content to ensure it is correct. There are two types of aberration: Chromatic and Monochromatic.

Chromatic is the splitting of white light into its respective colours/wavelengths. Monochromatic Aberration is the splitting of pencils of light depending on the shape, curvature, density, position and size of the lens. Chromatic Aberration as an inherent effect of light moving through a medium of one refractive index to another, cannot be solved but can be reduced by using lenses with a high Abbe value. The highest still used in spectacles is Crown Glass (n=1.523, abbe=59). Sometimes chromatic aberration is desirable, such as in diamonds (abbe=2.4), in which the splitting of light combined with a multifaceted surface, produce a multispectral 'sparkle'. Within telescopes and spectacles, this is undesirable though as the viewer would see colour fringing when viewing high contrast images such as a tree against a bright sky. On Monochromatic aberration: There are 5 types. Coma, Spherical, Distortion(Barrel and Pincushion), Petzval Field Curvature and Astigmatism.(You have articles for some of these). I would then briefly touch on causes of each of these and their current solutions or perhaps link to their own articles.

I would also suggest this article on 'Optical Aberration' is therefore divided into 'Monochromatic Aberration' and 'Chromatic Aberration' with this article only serving to briefly summarise 'Optical Aberration' before diverting people on.213.18.178.122 (talk) 14:12, 31 August 2020 (UTC) Mike (info@optics.works)