Using Setting Circles

[philsail1]

:sunny:Dear All,

Found a useful little write up on how to use setting circles. It's on "Cloudy Nights Telescope Reviews" and it's written by a guy called "Rinaldo." The article is titled "Use those setting circles!" The really good bit is the instruction on how to tell if the declination setting circle is reading correctly (a minus or plus reading). I have a Skywatcher Explorer 200mm Newt, with twin motor drives, and although I'm considering buying the "go-to" upgrade next year, I am determined to master the (seemingly) "black art" of using the Setting Circles first. I'm constantly searching around for helpful snippets, and I think the above is the best I've found to date. See what you think. Of course the one factor which governs everything in an astronomer's life (whether amateur or professional) is (no, not the wife!) the WEATHER!! Clear skies to all.

Regards,

Phil Edwards (philsail1)

[daz]

Phil

Could post a link?

[philsail1]

Yes Daz - but how does one do that!? - If you can do it please feel free to go ahead!!

Regards,

Phil Edwards (philsail1)

[tenbyfifty]

Yes Daz - but how does one do that!? - If you can do it please feel free to go ahead!!

Regards,

Phil Edwards (philsail1)

navigate to the web page, select the web page address in the address text box (near the top of your browser) by clicking on it, right click on the text, choose copy, then paste into your SGL post.

if the web addresss is very long, go to http://tinyurl.com/ and paste it into the really obvious place to paste it.

here's the link to the article:

http://tinyurl.com/2zscwz

[Macavity]

(Potential Hobby horse!) I suspect such things are indeed a "neglected art". It was clear to me that even quite MODEST mounts have a "reset-ability" (random error) within a few tenths(?!) of a degree. The limit is perhaps the circles (size, scales etc.), but., wtihin that, I sense these can be (easily) exploited to within a typical "finder field". Worthwhile exploring the possibilities anyway...

[philsail1]

Thanks Daz! I will do this next time. Of course your right "tenbyfifty" there must be some mechanical shortcomings in almost all but the most expensive (Takahashi etc) of telescopes, but for general astronomical viewing the accuracy of all but the cheapest (T****) telescopes must be acceptable enough.

What I find slightly cumbersome is trying to read the setting circles at night with a red torch in one hand, whilst trying to adjust the axis of the telescope with the other.

And another thing....... (I won't go on and on!) Why don't all telescope manufacturers get together and agree on what is/are the simplest and most easy to use Setting Circles - and then put them on all scopes! I'm sure this would increase their sales no end, where as at present a lot of potential buyers may be put off by the fact that setting circles are not always easy to understand and use. (This could be too shocking and simple a solution for manufacturers to take in!!)

Regards,

Phil Edwards (philsail1)

P.S. Looks like we've got a clear sky tonight in North Wales - I'll get my Skywatcher 200mm out (beggar "Eastenders!")

[tenbyfifty]

Of course your right "tenbyfifty" there must be some mechanical shortcomings ...

i think you mean mcavity

[lunator]

If you have a 1 degree+ eyepeice then setting circles should be able to get you too your target.

It takes a bit of practice but is straight forward.

Cheers

Ian

[philsail1]

Sorry mcavity! - got a bit overexcited in my eagerness to reply!! All good stuff in replies (as usual). It is good to be able to get advice and tips from so many, and so quickly on SGL. I was looking at the brilliant clear and cloudless blue sky from my office in Liverpool yesterday and thinking that "I'll get my scope out this evening." By the time I'd driven home into North Wales, the weather had begun to cloud over! By 8.00pm it began to rain!! (as the "scousers" say - I was gobsmacked!!). I was so looking forward to having a go with the setting circles. The weather has been generally dreadful this year - so inconsistent, erratic, and well, just hopeless for trying to plan anything. (The planets haven't exactly been conducive to easy viewing either).

Let's hope we get a dry autumn and winter.

Regards,

Phil Edwards (philsail1)

[Macavity]

What I find slightly cumbersome is trying to read the setting circles at night with a red torch in one hand, whilst trying to adjust the axis of the telescope with the other.

IF you DO want to illuminate setting circles, I found a nice little retrofit in Maplin's "Constant Current LED". These can be connected DIRECTLY to a stand-alone 9V (switched) battery box. The various componets can be "stuck" where your personal preference dictates (FNAR!) using double sided sticky. The resultant light levels, from the default RED LED, are really quit DIM (for normal uses!), but ideal for astronomical purposes?! Works for about 8hrs on a single battery charge. (i.e. Even more things to forget!)

[philsail1]

Nice one mcavity! I'll check this out in Maplins when we visit Chester. I suppose one could use the same system to illuminate the Polar Scope?

Regards,

Phil

[Macavity]

Dunno, Phil! I must admit I empathise with anyone who has tried the "polar scope limbo". Rumour has it that it is possible to shine a red light... somehow "across" a polar scope. If there is, I'm willing to learn.

[SteelRat]

Rumour has it that it is possible to shine a red light... somehow "across" a polar scope. If there is, I'm willing to learn.

If not actually across Chris - then down and at an angle. Obviously as long as it's not straight through and into your eye then it'll work. That was the only way I could see the markings in my old MT4 polar scope HTH

[Whippy]

What mount have you got Phil? You can modify some mounts so you can wire in a Red LED to illuminate the polarscope. I bought a HEQ5 already like that and it worked a treat. Otherwise as SR has said, shining a red torch down it does the job.

Tony..

[The Warthog]

Didnt' we have a thread on building a polarscope illuminator?

My suggestion for setting circles, as far as I've had any success with them, is to carefully wedge a screwdriver under them, pop them off, and throw them away. Then either star-hop, or get a goto mount.

[saturn5]

Best suggestion i've heard yet Warthog..good one mate

[lunator]

WH

Setting circle can be frustrating but once you get to work they can be useful.

Honest

[Macavity]

I have SOME sympathies with WH's stance.

One personal gripe is (n my expereince) the "Skywatcher method"(?) of using this "selective friction" idea to tie (or not) the circles to the (declination) rotation. Or maybe it's just me! Frankly, I converted my EQ3-2 to a "push-to" Alt-Azimuth. (It's now intuitive and great).

I'm sure we all remain aware of the difficulties of "Rosetta stone" documentation too...

[saturn5]

=

[philsail1]

Tony,

I've got the HEQ5 mount.

"Warthog" - I've almost got to that point (standing looking at the setting circles, with screwdriver in had quivering (and with dribble of saliva running from corner of mouth!). The wife's come out (in the dark) and seen me, and shouted "PHILIP" to break my trance like manic gaze!!) Seriously though, they (setting circles) can be most frustrating. As they are pretty vital to enable one to find "stuff" one would think that telescope mount designers would put more effort into trying to design a universal (no pun intended) set of circles that would work. (I thing the ancients had more success at finding stars with their setting circles - Stone Henge - than us in the 21st century!!

Yes is is a hassle Saturn 5. "Steelrat", I have used the "shine a red torch across the top of the Polar scope" method. It does work, but you really need an extra pair of hands!

I have taken the plastic cover off the side of my HEQ5 mount, and there does seem to be enough space to maybe fit a small red LED light. Perhaps I could glue/screw, or tape a battery holder and switch to the outside of the plastic cover plate to make an illuminator permanent.

[SteelRat]

"Steelrat", I have used the "shine a red torch across the top of the Polar scope" method. It does work, but you really need an extra pair of hands!

No I don't!

[philsail1]

Rumour has it that it is possible to shine a red light... somehow "across" a polar scope. If there is, I'm willing to learn.

If not actually across Chris - then down and at an angle. Obviously as long as it's not straight through and into your eye then it'll work. That was the only way I could see the markings in my old MT4 polar scope HTH

Sorry for misquoting you there "steelrat"! "Up, Down, Across - it all adds up to a bit of hassle!

Regards,

philsail1

[SteelRat]

Misquote? :?

Only had polar scopes on my little MT4 and EQ3/2 mounts, so for me just a hassle free 'two handed job to nail' - if you'll pardon the expression Never used a HEQ5 before, should be the same though?

Edit; Let us know how the mod goes.

[philsail1]

Thanks "Steelrat," I will let you know when I get around to trying to install a light for the Polarscope on my HEQ5 mount.

I initially found the operation of trying to fine tuning the Polar scope on the HEQ5 mount with one hand (using the steel levers either side of the front of the mount base) whilst in a twisted, crouching position, and holding a torch over the front of the Polarscope opening in the other, quite difficult - to the point where I felt my back was going to go out! (Mind you, I was silly enough to have placed the telescope and weights on the mount before trying to align the Polar scope!!). Soon learned not to do that again - I have now drilled three depressions in the concrete paving flags. I set the mount's leg points in those and then just check the polarscope. It's usually very near spot on. I think we all have to be expert innovators in this hobby! and this is where the forum comes into its own. In many instances we can happily (and quickly) avoid the pain of learning by (sometimes expensive) experience, by listening to the wealth of experience and advice from those who've "been there," "done that" and "got the T-shirt!" for want of a better expression, which can (and I'm sure does) save us "£££££" in the long run.

Regards,

Phil.

Regards,

Phil.

[SteelRat]

I initially found the operation of trying to fine tuning the Polar scope on the HEQ5 mount with one hand (using the steel levers either side of the front of the mount base) whilst in a twisted, crouching position, and holding a torch over the front of the Polarscope opening in the other, quite difficult - to the point where I felt my back was going to go out!

Since the last time I used a mount with a polar scope I HAVE had spinal surgeory - I'd like to point out though that it wasn't the polar alignment that did the damage heheheheh.

Anyhoo, I'm off to build a motorised focuser - with a clutch