GOTO with brightest star. How?

[dawson]

It's fascinating.

It's a shame we don't have an ardent mount leveller to join the debate. I'm not sure if Dion is a member of EMS. It might be an interesting discussion to start on SGL and see what they say. It might be a discussion which has been had numerous times there before.

It is funny though that lots of us have been painstakingly levelling when it doesn't appear to make any difference.

James

[Perkil8r]

With an EQ mount you are only reliant upon the axis of the RA being aligned with the axis of the Earth. Since the side to side (for want of a better term) is about that axis, as long as the axis lines up with the Earth via accurate alignment with polaris to ensure both axis are aligned to eachother then the side to side is purely down to the RA angle. The DEC adjstment is taken up with the Alt bolts when aligning to Polaris so that doesn't matter either. As long as the axis of the mount is exactly the same as that of the Earth the tripod is inconsequential.

[Guest Tweedledum]

The only mount I had that had to be absolutely bang on level was the Meade 10" sct. Just slightly out and the goto was pants, so bad that if i placed on grass rather than on the slabs as the damn thing was that heavy as it settled goto accuracy was compromised. Used mainly as push to, you really could swing it quickly and accurately with a widefield ep.

 

As withe Steve, my 8" newt on GEM could be almost out of kilter so long as reasonably polar aligned.

[glider]

I think I know what Dion will say!

 

Level doesn't matter.

 

You can hang an EQ mount upside down as long at the Polar Axis is aligned.

[+Ibbo]

The only mount I had that had to be absolutely bang on level was the Meade 10" sct. Just slightly out and the goto was pants, so bad that if i placed on grass rather than on the slabs as the damn thing was that heavy as it settled goto accuracy was compromised. Used mainly as push to, you really could swing it quickly and accurately with a widefield ep.

 

As withe Steve, my 8" newt on GEM could be almost out of kilter so long as reasonably polar aligned.

Thats because of the arms of the forks- nightmare esp on a flimsy wedge

[Guest peepshow]

Very interesting.

One thing about it all is, and I speak as someone who doesn't yet have any scope,

it all depends on whether one is just kinda star gazing or if one is doing

long time exposures.

[dawson]

It depends on your mount.

Alt-az mount:

- GOTO accuracy will determine how accurate the GOTO is (which js logical) and will also probably determine how well the mount tracks things (as I found if my GOTO accuracy on my alt-az mount was poor (for whatever reasons (not being level or just lazy two star alignment)) then the tracking was also poor and objects would drift out of the field of view more rapidly than expected.

- long exposure imaging can be done with an alt-az mount but "field rotation" limits the duration of images you can take without too much artefact appearing. Different areas of the sky rotate at quicker rates than others.

EQ mount:

- GOTO is simply a means to cheat and find objects easily (sometimes it can be quicker to slew the scope yourself if you know where the object is)

- GOTO accuracy plays no part in tracking accuracy, that is purely down to how well the mount is polar aligned.

One other consideration is cone error which i have a lot of. I'm hoping to resolve that soon though.

James

(I'm happy for any of my understanding above to be challenged, as i'm still learning this stuff myself)

[philjay]

Yes, with long exposure imaging polar alignment is critical purely to reduce the star trailing as much as possible unguided or reduce the amount of work the guider needs to do if autoguiding. But the goto can be pants. Goto is not needed for imaginf, its nice to have but not necessary, theres someone on here with a non goto mount that does autoguiding to great success.

The problem is when starting out alot of folks get sage advice on gear and techniques from wherever they can, thats great. But one has to differentiate between the almost @nal approach to setting up required by imaging and the more relaxed and less meticulous approach for visual. Thats the confusing thing. I do both imaging and visual so at times im just as ocd about pa as most but its nice to just relax and set up quickly sometimes for purely visual

[Guest Tweedledum]

Hi Steve,

 

The foeks & tube weighed the best part of 70lbs, they were absolutely solid!, one of the original LX200's before Meade started to reduce the size of the forks and mounts for the LX90's, never bothered with a wedge.

[+Ibbo]

Hi Steve,

 

The foeks & tube weighed the best part of 70lbs, they were absolutely solid!, one of the original LX200's before Meade started to reduce the size of the forks and mounts for the LX90's, never bothered with a wedge.

 

A proper coffee grinder then -I have the 8" version and was it noisy before it came out of its forks

[Guest Tweedledum]

Used to wake the neighbours !

[+RonC]

James, why is a Goto cheating ??? I want to see things and enjoy them, not spend all night looking for them! Each to his own I say!!

[dawson]

I say cheating tongue in cheek; i'd like to have goto knowledge, but i don't, so i rely on skywatchers goto

[+RonC]

It comes with time and experience (like most other things!)James!

[The Bagman]

Feeling smug have read thread, my LX90 being cleverer than me knows everything, but does require 2 star alignment

Edited July 25, 2013 by The Bagman

[Dennis1954]

Ok this is an old topic so forgive me as a newbie to this game. I have a Skywatcher Skymax 127 SynScan Telescope firsty I donot see why it has to be polar alined if you tell where 2 stars are and secondly if I am wrong how do you aline it.

[Daz Type-R]

Going from memory here (the mother in law has a 130 sync scan reflector) as it is a alt/az mount it does not need (nor can it be) polar aligned. It does however need to know where it is pointing. So first off put the tripod leg with N on it as close a direction as you can get to North, put in the date and time (American format) give it the coordinates of where you are viewing (for example 53 degrees north / 1 degree west). Now you have to do a 2 star or 3 star align ( I believe there are other options but I always did 2 star align and it was spot on). I always chose 2 stars that were approx equal in altitude but as far apart as you could get.

This method worked great for me / the mother in law and tracked objects for a good 20-30 minutes before requiring a slight adjustment.

[BAZ]

It depends which mount you have, is it the single arm ALT/AZ, or the EQ synscan with weights at the front end. If it's the EQ then it will need to be polar aligned, so that the movement of the mount follows the correct track across the sky.

If it's the ALT/AZ then Darren is correct.

 

Get a Dob!

[Dennis1954]

Thanks guys. I think that solves my problem or a least assures me I am moving in the correct direction.

[catman161]

The lead leg f the tripod doesn't new to be pointed north. My da ha the sky max 127 Mak on the alt/az mount and you just need to ensure that you put he correct lat/long coordinates and that the date and time are inputted correctly. The if you te using brightest star alignment you just need to ensure that you know the area of sky the first star is in so that you can pick the correct sky region i.e. If you pick Vega you need to pick north west on the handset (if that is where it is located where your observing from) so as long as you know where the star is in the sky or you have a star atlas you can just plonk the mount anywhere, level it and start aligning.

[Brantuk]

If you're still stuck Dennis you'd be welcome to drop round with it and we can have a look together - or I can come round to your place if you're not too far away. Long time since I used one of those mounts but sure we can figure it out together.

[Dennis1954]

Thanks for the offers and advice, as I said elsewhere I will wait and see some of you at Wymeswold. Thanks again.

 

Dennis