How Pictures Of Planets Should Be Corrected

  In this image you see three photographs of Jupiter along the top. Along the bottom are three corrections for an effect known as, “limb darkening“.


A simple procedure for the correction of planetary limb darkening

by António J. Cidadão

Limb darkening is a typical finding in planetary images, even at opposition, and can be considerably intense in gaseous planets like Jupiter or Saturn. It has a major role in the 3D perception we have when analysing a planetary photograph but, interestingly, it seems to be much more illusive at the eyepiece, probably due to the “logarithmic” way our brain interprets visual information.

The limb darkening effect can be deleterious in some occasions, like for instance the production of planispheres, direct photometric measurements, and the precise determination of a planet’s apparent diameter. In fact, multiple images have to be used to build up cartographic projections of planets, and to perfectly merge them together the brightness of a given feature should not change when it occupies different positions along the visible planetary disk. For this same reason, photometric measurements are usually biased by the feature’s position, say at the central meridian or approaching the limb. It is not necessary for the feature to be near the limb for brightness differences starting to become noticeable, but when it is the changes can be dramatic. This marked illumination falloff at the limb often artefctually decreases the apparent diameter of a given planet in CCD images, since with “aggressive” image processing and/or incorrect image settings the outer rim of the planet may be lost in the background…….read more

Here is a GIF of actual photos of a star.



Nicholas Bourgeois
Author: Nicholas Bourgeois

Creator & Editor of

A Free Book By Adam Kokesh


Available In Multiple Formats


How Pictures Of Planets Should Be Corrected — 7 Comments

  1. I happen to be commenting to make you understand of the cool encounter my wife’s daughter obtained browsing the blog. She picked up plenty of pieces, most notably what it is like to have a marvelous teaching style to get other people without difficulty fully grasp specific specialized topics. You really surpassed our expected results. I appreciate you for churning out those valuable, healthy, educational and in addition unique guidance on the topic to Sandra.

  2. I needed to post you one little bit of remark to finally give thanks yet again on the beautiful techniques you have provided at this time. It’s wonderfully open-handed of you to deliver unreservedly exactly what a lot of people might have supplied as an electronic book to make some money for their own end, notably considering the fact that you might have done it if you ever considered necessary. The good ideas in addition acted to be a easy way to be certain that other individuals have a similar zeal much like my own to grasp good deal more in regard to this problem. I know there are millions of more fun instances ahead for those who go through your site.

  3. I would like to point out my affection for your generosity supporting those people that really want help with this particular situation. Your personal commitment to getting the solution all around appears to be pretty invaluable and has always permitted women just like me to reach their goals. The insightful help can mean much to me and even more to my office colleagues. Best wishes; from each one of us.

  4. I am only commenting to let you be aware of what a impressive encounter our child gained reading through the blog. She discovered too many issues, including how it is like to have a wonderful coaching mood to have certain people completely fully understand chosen multifaceted topics. You undoubtedly did more than her desires. Thanks for producing these invaluable, healthy, revealing and as well as fun thoughts on the topic to Evelyn.

  5. I and also my buddies were actually checking out the excellent guides located on your web blog and so all of a sudden I got an awful feeling I never expressed respect to the web site owner for those techniques. These boys ended up certainly passionate to read through all of them and now have clearly been loving these things. We appreciate you getting indeed considerate and also for picking this kind of essential guides millions of individuals are really eager to learn about. My sincere regret for not expressing gratitude to earlier.

  6. I simply had to thank you so much all over again. I’m not certain the things I would’ve tried in the absence of these secrets discussed by you over that area of interest. It had become an absolute traumatic concern in my opinion, but witnessing this well-written approach you solved it took me to cry for contentment. I’m grateful for the guidance as well as have high hopes you recognize what a great job your are carrying out training the mediocre ones through the use of your web blog. Probably you’ve never come across any of us.

  7. I needed to post you that very small word to finally thank you so much once again considering the wonderful views you’ve featured in this article. This is certainly remarkably generous of you to allow without restraint all that a lot of folks could have sold as an electronic book in making some bucks on their own, mostly considering that you could have tried it if you ever considered necessary. These tricks likewise served to be a easy way to realize that other individuals have a similar eagerness really like my very own to see a little more concerning this condition. I believe there are many more pleasant sessions up front for many who start reading your blog.

Leave a Reply to jordan sneakers Cancel reply

Your email address will not be published.