From: Mark Gaffney <markgaffney@me.com>

Date: August 30, 2010 2:50:20 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Re: guiding last night...

It didn`t seem to be too bad.

I went as low as rate 5 & the start, stop take ups were pretty good. 

I tried rocking the OTA a little frontwards & backwards & there still seems to be some play there somewhere. 

It may be because the front latitude adjustment screw is removed, which I needed to do earlier on (a number of years ago now..!) to get down below 30 degrees in latitude (29 something here, actually)..

Mark.

On 31/08/2010, at 6:38 AM, Milton Aupperle wrote:

Mark;

Did you try point the main scope at a single bright star and seeing
how much slop you have on the RA and Dec axis using the hand controller?

If your mount had slop in it, and you removed it by tightening things
up, then your polar alignment will be off.

I'd also check the balance of the mount with all your imaging gear on
it too. Balance will result in subtle alignment changes too.

So there is no point doing a polar alignment if the RA / Dec still
need to be adjusted or balanced.

At least you can do the start / stop test in the daylight.

HTH..

Milton Aupperle

On 30-Aug-10, at 2:18 PM, Mark Gaffney wrote:

>
>
> Hi Milton,
> I`ve just come in & it`s 5.39 am as I begin writing. It was cloudy
> earlier.
> I`ve been out for about an hour aligning & have hibernated the mount
> but wasn`t too pleased with the general results.
> Achernar was a strange double point of light with some funny
> reflections from the moon which would have been behind the scope.
> Fomalhaut was in an easier position for the finder. These 2 were my
> western stars.
> I then made use of Canopus, Sirius, Rigel & Betelgeuse in the east
> which seemed to be as many extra callibration stars as the mount
> would use.
> When done with that, I slewed back to Canopus which was outside of
> the EP FOV...the Moon was a bit askew as was Jupiter. M 42 wasn`t
> too bad..perhaps not the best observing time because of early
> morning mist.
> Trying to avoid stars that`d strain my back or wet my knees with dew
> I tried Sirius again & Betelgeuse but neither were centred in the
> EP, though on the rim of the FOV.
> Canopus to finish with, was still significantly outside the EP. I
> corrected with the direction buttons to see where it actually was
> (..not too far off). It`s fairly high in the SW this time of morning.
> Every new correction of the finder put the red dot in a slightly
> different position. I can`t say I`ve had so much trouble with it
> before as I`ve had these last 2 maybe 3 times...
>
> So with these results it`s no wonder NGC 6744 wasn`t centred
> properly, previously..!
> I think I`ll have to go back to the drawing board next time, even
> checking polar alignment & will make sure before imaging that Go
> To`s are working OK before imaging..
>
> By the way I`m set to pay for the AC power adapter by PayPal early
> tomorrow morning..also a Hap Griffin NIRS -20 IR remote which is the
> only option (apart from the Shoestring DSUSB IR 1) for doing bulb
> speeds with my Nikon it seems..
> As usual Astronomy is a continually evolving adventure..!
>
> Mark.