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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