What does "well corrected" mean exactly?

The phrase "well corrected" is used a lot among amateur astronomers, but I have yet to see anyone explain exactly what the term means in the optics field. The phrase certainly has no intrinsic meaning, so to speak. I gather that it means "true to life" or "brings all colors to same focus" or some such.

Can anyone here (Mr. Christen, perhaps?) explain what this phrase means exactly in the optics business?

Oh, and another thing, what does the term "saturated" mean in the context of the color of an object when viewed through a scope? I gather that it means "intense" or "vivid," but, again, I've never seen anyone define the term.

In my field, law, words are our only tools, and I find that precise definitions are desirable, even necessary. I also find that not everyone has the same understanding of what words mean.

Thank you.

Bill

Bill:

Well corrected and the other terms can truely be described in absolutes. Well corrected means any abberation its refering to is held at a very low level - possibly not noticeable to the average observer. Yet to an experienced critical eye, the abberation might still be seen. In your field the term "reasonable doubt" come to mind. One could define it in general, but as you know, what's reasonal to one group or individual may not be to the next! Think of "well corrected" as more of an advertising term than anything. Without knowing the exact case by case specifications it can be pretty meaningless.

I'd say these most terms must be considered when compared to the whole. Saturated or vivid colors in an object are relative to other objects in the night sky - the VAST majority of which are shades of grey. I've found that now that I've reached middle age, the "vivid" colors of blue or green in planetary nebulas are difficult or impossible to see, yet other observers will look in the eyepiece and say wow, that's really blue. My wife is a perfect example; after being around me and my hobby for 25 years, she still says we astronomers "make up" with our imaginations much of what we describe at the eyepiece. To her it NEVER looks like a swan, a hunter, a dumbell, nor does it show any color.

In regulatory speak, well corrected optics are those that are not poorly corrected.

It is amazing to me how much time we have to spend just to figure out what the venders are telling us. Unfortunately what you say is correct most of it is either used incorrectly or simply nonsense.

Robert Apruzese said:

"Well corrected" is an adjective used by sellers of Chinese refractors using so called "Vixen spec" optics. Check some of their web sites and you will see this is the case. As to what the phrase means. I believe it means absolutely nothing. It is marketing jargon. And I am willing to bet that Roland will agree with me on this.

I have used the term to describe eyepieces in fast newts and I think there are good uses for "well corrected" in describing not only eyepieces but optics as well. We are all familiar with under correction and over correction, in this sense, well corrected means "dead nuts on."

I did a bit of searching through the forums and it is clear that Roland uses the term "well corrected".

http://www.astromart.com/forums/viewpost.asp?forum_post_id=604208&poll_id=&news_id=&page=

http://www.astromart.com/forums/viewpost.asp?forum_post_id=603581&poll_id=&news_id=&page=

http://www.astromart.com/forums/viewpost.asp?forum_post_id=556727&poll_id=&news_id=&page=

Bottom line: "Well corrected" is not necessarily hype, it's a term with real meaning.

Jon Isaacs

Well, looking at all the stuff above, let's just make it up and let's stick to wavefront error. How about:

Wave front errors for spherical abberation, coma, spherochromatism, astigmatism and whatever all fall inside the Airy disk from C to F on axis.

Jeff

It means you expressed some sort of view about some sort of technical aspect regarding optics, Roland saw the post, and explained why you didn't really know as much as you thought you did.

regards
Greg N