llanitedave
(Humble Megalomaniac)
05/18/08 11:31 AM
Re: Strange Results in Eyepiece FOV Comparisons

Quote:


The field stop diameter very well *should* be the standard for eyepieces, although the apparent field of view is something people might like to look at to see how much of a span they will see when they look in the eyepiece. I see little reason to "calculate" some odd-ball "real apparent field of view" that pulls in the field stop number to the equation, when the simple field stop formula gives great results to begin with. Introducing some "fudged" apparent field is just unnecessary and potentially confusing. Clear skies to you.




OK, I get what you're saying here. Not all eyepieces have a directly measurable field stop, however. So what the drift test gives me is a kind of "virtual field stop" number that I can use to predict true field of view for a given eyepiece in any telescope.

That seems rather arbitrary too, but at least I see how it can be tied to something physical -- even if it's just imaginarily so.



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