Another newbie CG-5 question

[Stinky_Pete]

Just a curiosity thing really. When i perform a GOTO alignment with my CG-5, i usually do 2 star align, followed by a couple of calib stars then a polar align (usually with a balowed illuminated eyepiece). My question is after i have adjusted the mount for the polar alignment (which is almost always out) should i then redo the GOTO?

[Mak One]

I do the polar alignment first (I use a polarscope now rather than a rough alignment up the empty axis) then do the star align/calib. To my mind this sets the scope up on the correct axis and will improve your star alignments. If you star-align and then polar align, any ALT/AZ changes in mount head position you make when doing the polar alignment may throw your goto out, and tracking.

I've found the polarscope has improved my goto/tracking accuracy no end.

How's the coffee with your CG5?

[brantuk]

Yup - allways level the tripod and do the polar alignment first with any equatorial mount - especially if imaging where it's essential

[carastro]

I have a GC5 GT and always do the polar alignment first, I haven't heard of any-one doing it after the 2 star alignment procedure which must surely be a waste of time if you haven't done the polar align first.

How's the coffee with your CG5

I think this is a joke about the coffee grinder noise they make and boy is it noisy when it's 2am and the neighbours are asleep.

Carole

[Stinky_Pete]

Yea its is a tad loud, and it echos off the houses around me just as bad. I try to have most of it set up before 9pm and stick to one target for immaging per night.

I should have said, i do a rough align using the polar scope, 2 star etc for the goto and then use the polar align function in the nexstar handset to tweek the alignment (i can usually go 3 mins or so unguided).

[brantuk]

Three mins? you're robbing yourself of precious exposure time - you'll get ten mins easy if you PA first

[Mak One]

I think this is a joke about the coffee grinder noise they make and boy is it noisy when it's 2am and the neighbours are asleep.

Yep. We CG5 owners do get a gentle ribbing about coffee grinders etc. I've no experience of other mounts - mine does make a bit of noise when slewing, but otherwise it's fine. No complaints from neighbours so far, but then the Tesco etc trucks rolling past 20m away tend to drown anything out anyway... In any case my woolly hat muffles any noise nicely for me...

As for the tracking time, what Brantuk said earlier.

[Stinky_Pete]

10 mins unguided? really?

wonder what i am doing wrong then

[Mak One]

SP...

I'll defer to Brantuk on that one as I don't do guided - I take it you're on DSO's?

From my experience though even with a "quick align" I can hold station on solar system stuff to image happily with a webcam - certainly longer than 3mins without adjustment. I've also imaged doubles in the same way without them wandering about.

Never tried the polar alignment from the handset (sorry - it occured to me after I'd posted the original reply this is what you meant ) but wouldn't it just cancel out your previous alignment work rather than enhance it? There are other tools like the calibration stars, PEC and goto approach etc for increasing accuracy in smaller parts of the sky. Make sure your alignment stars are as widely spaced as possible - I always do the 3 calib stars as well now. I've only ever had "bad" alignment/tracking when I've skimped on these steps.

As I mentioned, the polar alignment scope is excellent and far from "rough".

The once I've done a solar system align on Saturn it took me across to the moon absolutlely dead centre, and back and forward a few times spot on.

The CG5 gets some stick on here but I find it's a great mount (and at a very reasonable price at the time from FLO that allowed me to use the cash saved on the equivalent SW mount on an eyepiece set).

Sorry I can't be more help. Good luck and keep us posted.

[Glider]

My CG5 is louder than my HEQ5 when fast slewing but just as quiet when tracking normally.

I think Brantuk meant the target will stay in the FOV for 10 minutes, which is fine when webcamming as you can accept some wandering but not the same when doing single long exposure subs.

[brantuk]

Yes - it will track fine for ten mins or more - and you can get lots of solar system frames. For dso's though you'll have to guide - I notice you have the gear for that in your signature.

Thanks Glider I could've been more definitive.

[Stinky_Pete]

phew! thought i was being a numpty for a min, yea i meant when imaging DSO's i can get 3 min subs which are usable. Have just started dipping my toe into auto-guiding this weekend and im definitely getting there but still have a lot to learn

[brantuk]

Actually Pete - 3 mins unguided, and given that you've been polar aligning after 2 star align - is amazingly quite good lol

[philming]

Hey there.

Rumor has it that the mounts knows how much you move it around when doing the HC PA thing. Well my recent tests show it DOESNT.

I did just as you do. Boot up, 2 star align + a few extra sync stars, then PA (it wont allow you to do it unless you've aligned with 2 stars anyway), then toggle off-on, and redo the align routine. I know it's a waste of time, but that seem to be the way to do it.

I've tested this a few nights ago. After doing a 2 star align + sync, the PA, then slew to a bright star via the HC, it was quiet some way off my red dot. Had to do the above routine in the end.

[continuum]

Philming - Iguess you are talking of Celestron's "All star Polar Align" as obviously you do not need to be aligned or even powered up to do a manual polar align through a polarscope. With the ASPA you are right you have to do a 2 star align first.

Hope this helps the thread.

RonJ