--- In OAFs@y..., attilla.danko@s... wrote:
--- In OAFs@y..., jean_dorais@s... wrote:
>
What makes you suspect there's any kind of problem?
Well, when I do a star test, I don't see anything resembling
a 'good'or even 'so-so' result....the airy disc looks like...er
cow
poopoo....
The star test can be hard to apply. It needs extreemly good
seeing and fully cooled mirror before you will see the
classic airy disks.
However, there are some basic things you can look for even if
you dont see an airy disk:
Sorry that post was truncated. Here is the rest:
As you rack in and out of focus, does the star blur stay round?
Does it get elipitcal? Does it have spikes or look lopsided?
At about 200 power rack out of focus a star so that its about 1/10
of the apparant field. Now rack in about the same distance. Do
the two blurrs look different?
If the answer is "yes", then there is a problem with the optics
(assuming good colimation and cooling).
If the answer is "no", then you scope could be good, or not-so
good, but its hard to diagnose in email.
In either case, Its a good idea to have some people look
throught your scope. Planets are a good target for checking
optical quality. It would be even better if someone else had
an 8 inch scope for comparison.
I dont have an 8" to compare with, but I'd be happy to look at,
and through your scope, at an observing session.
Can you arrange for a clear night ?
-ad
