Hi Ray -- Good luck. Let us know haw you do with this.

Best regards

Frank

> I hadnt thought of that but it should work great and I am going to borrow
> an ST4 from a friend for right now. Pays to have great friends dont it. So
> that will really help me. Thanks for the idea..
>
> dray
>
> Frank Loch wrote:
>
> > Hi Ray -- Gene's suggestions below are excellent. However I use
> > another method which works well for me.
> >
> > With the CCD camera in place, I center a single medium bright star
> > in the FOV on my computer. BTW, I have a red magic marker ink
> > "dot" on my monitor screen in exactly the center of the FOV.
> >
> > Then I defocus the star --enlarging the rings till they virtually fill
> > the fov. Now you can easily see the amount of "de-collimation" that you
> > have. I then start to "tweak" the collimation screws. After each "tweak"
> > I recenter the star. I repeat till all is centered at the center mark on
> > my monitor.
> >
> > I have a permanant pier mount. I collimate at the most twice a year.
> >
> > Best regards
> >
> > Frank
> >
> > > Ok to everyone that has helped on this. I see a light at the end of
> > > the tunnel here. I can from most comments adjust the collimating using
> > > the star method. This all makes sense to some degree. I am not going
> > > to rush right out and spend money on a collimator. I will give it a
> > > chance to see, what I see, when viewing. I may still want to invest in
> > > the collimating device at a later date just to make extra sure I have
> > > it set the best. I am looking at long duration astrophotography. And
> > > with a viewing site at 8000 ft level I should have some fairly good
> > > seeing nights. I have a cliff overlook at that level. Thanks again for
> > > all the help to everyone.
> > >
> > > dray
> > >
> > > Gene Horr wrote:
> > >
> > > > "D.Ray East" wrote:
> > > >
> > > > > I asked one of the local group here about collimation on the 12
> > > > > inch Meade LX200 scope. He said the is very little you can do to
> > > > > them and they always come out right from the factory. I am
> > > > > wondering is this true?
> > > >
> > > > No. Merely slewing from one side of the sky to the other will ruin
> > > > perfect collimation (see Legeault (sp?) for a very good discussion
> > > > on this).
> > > >
> > > > Now, to confuse things further, this may not matter too much for a
> > > > beginner. Critical collimation becomes important for high power
> > > > planetary work or when you are trying to get that last few
> > > > percentage points of resolution. For typical medium/low power DSO
> > > > viewing the collimation can be waaaaaay off for the typical user
> > > > before it even becomes noticeable.
> > > >
> > > > But IMO it is still a good idea to get in the practice of checking
> > > > collimation after the initial cool down. Once you've done it a few
> > > > times it becomes a simple and quick procedure. This is another good
> > > > project to practice in the back yard so that you don't waste dark
> > > > sky time learning mechanics.
> > > >
> > > > A few tips:
> > > >
> > > > Don't use too bright of a star.
> > > > Use the highest power the seeing will allow (at least 250X.
> > > > Preferably closer to 500X)
> > > > Defocus just enough to see the diffraction rings.
> > > > Center the diffraction rings, NOT the "donut hole".
> > > > Keep the cell on the pivot point by loosening two and
> > > > tightening
> > > > one.
> > > > Tighten the screws down when done.
> > > >
> > > > BTW - a LOT of the negative comments you hear about mass-market SCTs
> > > > come from people not allowing them to cool down and not properly
> > > > collimating them. Of units produced over the past 5 years or so I
> > > > have only seen one truly bad set of optics and only a handful of
> > > > poor ones.
> > > >
> > > > Gene Horr
> > >

Best Regards,
Frank Loch
Try Deep Space 99 at:
http://home.early.com/~floch/index.html
TPoint & DEC Bearing Mod at:
http://home.early.com/~floch/observatory.htm
Hubble's Variable Nebula project page:
http://home.early.com/~floch/lnai20.htm

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