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Best night yet - Thanks Tel, et al

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#1 hamdul

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Posted 19 June 2013 - 10:11 PM

A slightly gibbous moon but what the heck the sky is crystal clear so sore back and all the scope gets set up. Go thru the alignment procedure using Polaris and Vega, but because of the brightness of the moon decide on an easy target-Saturn. Push the buttons the motors do there whirring thing, the scope stops and in the eyepiece there is Saturn. Not in the center, I'd say it was just inside the field of view at around 5:00 o'clock. To see if that was a fluke I then go to Albireo and bingo there it is and again at that same 5 O'clock position. My luck is holding out so I try for something visually harder, The Ring Nebular. The motors whir, the scope stops an there it is. Again at the 5 o'clock position and at the edge of the field. I assume that because all my targets appeared in the same place, something was a bit off in my alignment. My back is starting to hurt but I decide to go back to Polaris to better align the finder to the scope. A short but great night so thanks to Tel and all the others who have helped me with my various concerns. :bow:
Fred

#2 Tel

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Posted 20 June 2013 - 03:24 AM

Hi Fred,

Many thanks for the acknowledgement. Much appreciated.

It must be really self satisfying to know that you're now hitting target each time although you don't say which size and type of EP you were using, (i.e. whether it possesses a wide angle FOV or a small one and whether this was the same EP as that which you used to make your alignment)?

Also, don't forget that you can always employ the "Sync" feature if you wish to stay for a while examining a certain portion of the sky or even the "Precise GoTo" particularly if the object you seek is very faint.

Look after that back !

Best regards,
Tel

#3 Peter9

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Posted 20 June 2013 - 03:27 AM

Hi Fred,
Pleased you had such a good night. You will find that wherever the first object fall in the F.O.V after alignment, on most nights, the others will also fall there.
As for your aching back, get a chair or better still, an adjustable stool and sit down. Not only is it good for your back, you will see a lot more.

Regards. Peter.

#4 hamdul

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Posted 20 June 2013 - 08:31 AM

Tel,
For alignment I was using a 25 mm. with crosshairs. For the Go To's I used the 25 mm. that came with the scope. For viewing Saturn I bumped up to a 16 mm. Brandon Orthoscopic. The one thing that was happening that has me puzzled was drift. Of course I didn't stay on any single object very long except for Saturn. (Had the neighbor out looking at it) Saturn was drifting slightly South in the field of view. Down as you looked in the scope.
Peter,
I did have a chair but this 86 year old back still had to move it East and West as the scope went to different objects. Just chalk it up to the ageing process, but thanks for the advice.
Fred

#5 Tel

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Posted 20 June 2013 - 08:50 AM

Hi Fred,

I think you'll find that GoTo accuracy can and will vary somewhat from night to night, all essentially depending on the initial accuracy of the alignment, but drift of the object, when once in the EP, is most likely down to backlash settings, the directions in which you recentralise it when "off centre" or, as I mentioned in that tracking review paper I wrote for CN back in '07, the position of the object you are viewing in the sky, relative to the Eastern or Western Hemisphere.

If you think I can help further by expanding these ideas , please do let me know.

Best regards,
Tel

#6 Peter9

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Posted 20 June 2013 - 09:24 AM

Hi Fred,

I wish you well. Just hope I am still able to observe at 86. All power to you.

Regards. Peter.

#7 UncleMossy

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Posted 22 June 2013 - 11:11 PM

Hello Fred,

You will find that wherever the first object fall in the F.O.V after alignment, on most nights, the others will also fall there.

Regards. Peter.


This is one of the most important things to remember.
Your target object will be in the same direction all night as Peter said.
The object may not have fallen in the field of view at higher magnification but it would still have been over at the 5 o'clock position.
You didn't do anything wrong with your alignment, that's just the way it is and every session will be in a different spot.
I find myself saying "Ok, we're over there tonight" after a few targets fall in the same place.

As for the drifting in the FOV, if once you've centered the object it starts to drift just press the arrows in the opposite direction until you take the slack out of the gears.
This drift can vary depending on where your scope is pointed at the time and what o'clock you're approaching from.
These are all things that work for me.

I would also highly recommend an adjustable chair or stool even if it's just to lean on.
Some people use a walker for support with success and I sometimes wish I had a crutch.

I wish you clear skies and many more "best night yet" nights.

Cheers
Jim






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