Bloddy Setting Circles

[jasperuk]

As i cant afford a GOTO upgrade for the old EQ3-2 i decided about 2 hours ago to try and work out the setting circles from my living room with no view of the sky, stupid maybe not decided yet...

I rough aligned to NCP with compas and the 52 deg angle already set, i then checked the RA and DEC for polaris and rough alighned the scope poining towards polaris. I then set the RA to 2h 47min approx and the DEC is near to 89deg which is about right....remeber i can see the sky but at this point i thought i was doing well....

I loaded Starry night on the PC and got the co-ordinates for mars, seemed ok RA 10h26 DEC 12h32, then i tried M3 Cluster which is apparently at 13H42 DEC28H18....My scope woudl be upside down and about to fall of its mount...

I just dont get this at all what am i doing wrong appart from being indoors

[garethmob]

unfortunatly setting circles on the EQ mounts arnt very accurate from what iv seen (on my eq2 they were shocking) im not sure what to advise to be honest hopefully some one might have an idea

[eddy]

Try changing the 13hr to 1hr (12 hour clock)

Thats what i do and it always works out fine for me, for example, M101 is 14hr 03min i do 2hr 03min and its spot on

[jasperuk]

Bloddy hell

[Double Kick Drum]

I gave up trying to use setting circles a long time ago. They are not that accurate on EQ mounts and more trouble than they are worth.

I now use Cartes du Ciel maps and star hop. Stellarium can work just as well and is a free download if you don't already have it.

Happy hunting!

[JamesM]

The setting circles are way too small to be of any real use in my opinion. I think they are included to make the mounts look more scientific of to suggest notions of precision and quality engineering. Better to use Stellarium or Cartes du Ciel with red dot finders such as Telrad or the Riger Quikfinder to be honest and certainly a lot quicker.

James

[Beardy30]

i would forget them they are a waste of time but they do have closer acuracy with the 12 hour clock i belive, but to be honest i would n't bother , i think they jsut add them to the mount to make them look cool.

[stevetynant]

Not very useful for you JasperUK I'm afraid but in case this thread confuses any fellow newbs - setting circles on a Dob however are a very useful addition and can be suprizingly accurate

Good luck with the star hopping and on a positive note its a great way to learn the skies

[jasperuk]

Well i managed to get the theory sorted out now thanks to one and all but ....

The RA circle spins round i presume that supposed to do that as the DEC does not you would have thought the RA would be the same ????, can i stop this happeneing as accidentally catching it during a move from one star to another buggers everything up once set.

"use Stellarium or Cartes du Ciel with red dot finders such as Telrad or the Riger Quikfinder", i have both od these now and whats Telrad or Riger how do these help ?

[chiltonstar]

They are fiddly to use first of all, but I would persevere if you can. I don't have GoTo either, but use setting circles to find faint fuzzies with my mount (Vixen SP). I align accurately, then move to a nearby brightish star, reset the RA and work out any offset needed for the Dec, then reset both to the required position, which gets me within a finder's field of where I'm aiming for.

If the RA moves round to easily, either tighten the screw if there is one, or use a bit of black insulting tape to stop it moving too easily.

Chris

[stevetynant]

Telrads and Rigels work in the same way - their basically an unmagnified finding scope that projects red concentric circles onto a small perspex screen superimposed on the sky that your looking at in real time. The Reigel has a 2 degree circle and the Telrad an extra circle at 4 degrees I believe. Many of sky maps will have Telrad circles on them so you can position your scope relative to the object your attempting to view and certainly Stellarium has a function to add Telrad circles to its view- not sure about the other one.

If you do a search on telrad you'll find plenty of info their really popular amongst the forum members

[jasperuk]

Ahhh now i get the Telrads thing should have gone on youtube to start with.

Are there any holders out there that will hold a laser pen in place so i can point a green laser in the direction the scope is looking ?

[bish]

Being a bit lazy I've never even tried to use the setting circles. Of course this may be a false economy of time when I spend hours in the freezing cold looking over star maps.

[garethmob]

You can get laser attachments. I know scope n sky's sell one (but their customer service is dubious at times) otherwise no doubt there will be one on eBay. Lasers don't like the cold or more importantly battery's don't but if you put some pipe lagging onto it should be fine:)

Sent from my iPhone using Tapatalk

[JamesM]

There are these on Ebay. Many astro retailers (Telescope House and MC2) used to sell these holders along with the lasers but the cheaper one's were so unreliable, (I have had two) that it probably wasn't worth there while supplying them. There is a proper dedicated laser finder that Rother Valley promotes but you're looking at £95!

James