Optical aberrations: Quick guide

[Scosmico]

There are many things to consider when choosing eyepieces, and/or evaluating its qualities. Many times reading the treads posted here on SGL I was confused with some terms, specially those terms regarding optical aberrations.

I found a good guide in the Nikon site regarding optical aberrations. I hope to help those to understand some comments of the most senior observers and also evaluating your own kit.

Enjoy the sky!

Nikon | Instruments Products | What is aberration? - Pin hole specimen image/Explanation

[Stars Fall]

Nicely explained, I was looking 4 this for awhile, thanks

Sent from my HD7 T9292 using Board Express

[Ags]

It has some nice examples, but I wonder... "what is NA?"

[themos]

I 'm pretty sure it's the f-ratio

[John]

It's a term relating to microscopes. I found this elsewhere on the Nikon website:

"Numerical Aperture (N.A.): This is a number that expresses the ability of a lens to resolve fine detail in an object being observed. It is derived by a complex mathematical formula and is related to the angular aperture of the lens and the index of refraction of the medium found between the lens and the specimen. To get the best possible image, you should have a condenser system that matches or exceeds the N.A. of the highest power objective lens on your microscope. (note, N.A. is only important with high power microscopes)."

[John]

With regard to aberrations and astro optical systems, I find this link useful:

Got Aberrations?

[The_PSY3NTIST]