Diffractions rings sharp extra focal, fuzzy intra?

I have been trying to determine if my scope has a bit of over or under correction. Over several nights I tried observing the diffractions rings intra/extra focal. Extra focal the diffraction rings were consistantly very fine and sharp. Intra focal however, the rings were still quite discernable but appeared a bit fuzzy in comparison.
Would that be any indicator of over/under correction? thank you, Bill

Bill,
Reflector?
That would be a sign of over correction. However, I have seen atmospheric turbulence cause the same results. Another cause could be the cooling of the glass. It is said that mirror makers used to leave the mirror slightly under corrected so that they would perform better under cooling conditions.
The star test is a very sensitive test and can tell you a lot but requires ideal conditions. Star test often and get to 'know' your mirror. Don't let the knowledge that your mirror may be less than perfect (none are) discourage you from enjoying the views it provides.

Try this free star testing software from Aberrator.
http://aberrator.astronomy.net/

Bob