How to use setting circles on a small telescope (and why they don't work!)

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The awkward truth about the effectiveness of setting circles fitted to small telescopes.
Erratum: The scale of the AA road map referred to is in fact 1:50,000 and not 1:500. So what's another 49,500 between friends? RJD
Presented by Robert J Dalby
for The Astronomy and Nature Centre
Produced by DB Video Services for Astronomy and Nature TV

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14 июл 2024

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Комментарии : 182

@mercskag7893 2 года назад

I accidentally found this 10yr old video but learned something in a few mins that has eluded me for years. Thanks.

@gooner9038 6 лет назад

First, I enjoyed your beautifully produced and informative video. However, my experience of using setting circles is different than yours. My first scope was a 70mm refractor by Jason bought from the Sears & Roebuck catalog back in the 70s. It had a crummy equatorial mount that I used with great success to get pretty close to the vicinity of many deep sky objects using my Norton's Atlas. Polar aligned as well as I could get it, then finding a bright target star and setting my circles, allowed me to get to pretty much anything my small scope would resolve. A 20mm eyepiece, a little tweaking with the fine adjustment knobs, and patience, did the job. I think it does something of a disservice to beginners to discourage them from using the setting circles available to them on the less expensive beginner scopes. While they certainly don't offer the precision of expensively machined equatorial mounts, the practical exercise of navigating the night sky using the standard coordinate system outweighs any transient frustrations of using less than ideal equipment. Thanks again for the videos; I enjoy them immensely.

@hcic8738 Месяц назад

Well said

@JohnMHammer 8 лет назад

The first two paragraphs just for some background, please bear with me: My first telescope as a child was one I bought after spending about a year selling cards, stationery, and wrapping paper door-to-door. It was a 3" Newtonian with flimsy folding metal legs and a ball-and-socket alt-azimuth mount. I'm thinking back 45 years to when I was 6-7 years old but my memory is that the tripod was a horror but the optics were pretty good, giving me clear images and rarely requiring collimation. I recall the little ball-and-socket bearing being really smooth, too! I explored the moon, watched Jupiter's moons dance, enjoyed Saturn's rings, found the Pleiades AWESOME, and located a bunch of Messier objects with that scope in my light-polluted suburban NYC backyard and garage roof with street lights almost directly overhead in every direction. My second telescope I put together from a bunch of different parts from different manufacturers I bought as I saved up for each bit: Mirrors, tube, focuser, mount, pier, eyepieces, yadda-yadda. In the end I had a 6" Newtonian on a very nice alt-az mount with slow-motion knobs attached to a solid pier and pretty good eyepieces. Only bad part was I was still so young, and small for my age besides, that I could barely move the thing even when it broken down to its three main parts - mainly because the pier was so heavy. But I got better views of everything I had seen before and worked my way through almost the entire Messier catalogue by the time I was 9. Still all from my backyard. Power-related blackouts were the only thing that got me to some of the Messier objects. My third telescope I bought from Edmund Scientific. It was an 8" Newtonian with an equatorial mount and at the time was a huge expense, at least two years of my kiddy income. Gosh, I was so excited to have setting circles! Yes, the precision was terrible just as you explained in this excellent video. However, I only needed to get within 3°-5° of an object and could then use signpost stars in the finder scope or a little spiral scanning with a wide-field eyepiece to acquire my target. I added filters to my eyepiece collection including, by my teens, nebula and light pollution filters which worked much better than I had expected. I easily finished off the Messier list and moved on to new-to-me fuzzies just for the fun of it. I had this scope into my twenties before donating it to the museum I was working for at the time. Um, anyway, the short version is: While I completely agree that the small setting circles on most amateur scopes aren't precise simply because of the coarse calibration marks, using them can get the scope close enough to use a finder or spiral scanning and for an object with which the observer isn't at all familiar that can be quite helpful. Also, simply using the circles can help a student or new astronomy enthusiast to develop a better intuitive understanding of where things are in the sky, how their locations are mapped, and how things move due to the rotation of the earth and other factors.

@akshatchobdar3038 3 года назад

Im surprised that such a long para is not edited. Good good.

@floridagliderpilot4101 3 года назад

True and when you are using a small scope like an ST80 with a 400mm focal length, you can see nearly 6 degrees of sky with a wide angle eyepiece. Simply stating that small setting circles are completely useless without considering the FOV at the eyepiece, and the ability to sweep just outside the FOV for the target is malarkey!

@AntPDC 6 лет назад

Really quite excellent in every way. Totally solid education without the fluff, utter rubbish and BS we have come to expect in much YT astronomy content. Thank you and congratulations.

@rico00042 9 лет назад

For anyone stumbling on this hilariously entertaining video and getting miffed about it not being the static instructional video they were after. Use your smart phone, turn on the gps calibrate the magnet by flipping it a few times, aim it at the sky like an overlay and point your rig where it shows you. you can also use stellarium or other planetarium software to get real time ra/dec figures then use those to orient yourself "in the neighborhood" and use the star hopping and pan/scan method from there. c6-xlt/cg-4 no drives(yet)

@RocketPlanet 11 лет назад

I think it’s going to take longer than 18 mins of practical trial to come to the same conclusion yourself (I took weeks!). The ‘other’ setting circle vids simply take the Aristotelian line of “trust me, I'm an expert' then tell viewers how to use them without a hint of recognition that their success in use is dependent on their diameter. In contrast, we said: ‘here are the facts about small circles, think it through with us to see why they lack useful accuracy'. Sorry you didn't like it. RJD

@rexnemo Год назад

I used to work with Shadow graphs measuring angles and the best we could measure was 1 minute and that seemed pretty accurate . Astronomy appears to measure angles in much finer graduations of the degree . It's fascinating and I guess that as a beginner I'll be able to see the stars which are more well known but that's good enough for me . 🙂

@igrieger 4 года назад

Finally, finally, I found it! Thank you so much for this detailed information! Immediately subscribed! Cheers!

@floridagliderpilot4101 3 года назад

I used the setting circles on my Exos Nano (a $99 mount) with my ST80 and a 25mm eyepiece. The RA is about 3 inches in diameter, and the DEC is 2" in diameter. By your explanation they should not work at all, but they work just fine. I found the double cluster, ring nebula, M81 and M82, fairly easily using the setting circles. These are objects that are not difficult to find but I wanted to see if I could find them using only the cheap setting circles because I could not see them naked eye during the full moon . Of course, the setting circles worked just fine and I found all targets easily. Move to a nearby star, register the RA and DEC, and then move to the new target coords. A brief look just outside the FOV in dec, and NO surprise there's the target. Now I would not recommend 2" setting circles on long focal length instrument, but simply stating that small crude setting circles don't work is just simply not true.

@superspit 7 лет назад

Calmly explained, great audio quality and no incredibly annoying intro noise/music. You sir are a sound engineer!

@gettingpast4391 4 года назад

Yes those tiny circles on the junk mount are nearly useless, but 3" or 4" setting circles are totally useable. They will get you within a couple FOV of the target. It's really not difficult to pan around gently until the object slips into view, especially when the other option (aside from expensive mounts or goto) is star hopping... essentially starting from ground zero. If you have just one large circle (RA for example on a Classic Celestron C8), then you are already half way there. You simply move up and down in DEC with the slow motion control and there's your target. The C8 has a dec circle diameter of only around 3" and I had no problems using settings circles with that scope IF I could see the target visually without great difficulty. No small circles aren't very accurate but they don't really need to be unless you are expecting to land right on it.

@angeltensey 6 месяцев назад

In my opinion, even simple settings circle is a good tool for a novice to blindly (and approximately) find any object they cant locate visually.

@edeszabo1977 10 лет назад

THANK YOU SO SO SO MUCH, I tried yesterday evening to set it up until I came across this video...I really had trouble to set it up accurately...but now I wont bother its just not worth it...VERY USEFUL VIDEO... I love all your videos, I learned a lot from you guys from seting up the eq2 mount to eyepieces and Barlow lenses pretty much all most everything. THANKS

@eshwar2496 4 года назад

Thank you so much from India. I have struggling how to use my Newtonian Reflector (Celestron Powerseeker 114EQ).for a long time, until I found yours..... All video are worth, but only until you come. Thank you sir, Love from India.

@doit4thefun803 4 года назад

Eshwar haha I have the same problem with the same telescope

@dwgwnr1969 4 года назад

Same here..same scope..gonna build a dobsonian mount for it

@mazdamaniac4643 Год назад

As a very new astronomer and after much scratching of my head on how to figure out setting circles, this video was absolutely brilliant for explaining this complex witchcraft. What wasn't so brilliant is learning that my EQ1 mount, which came with my telescope and many hours were spent setting it up as accurately as feasible, is practically useless for anything resembling finding a target in the night sky...no wonder stellarium keeps laughing at my struggles...oh well, but that's what wages are for, pursuing this wonderful new hobby!

@thumbpickr1812 6 лет назад

Very useful insights into the pros and cons of setting circles. Thanks!

@neilamadhava 12 лет назад

I want all your kit and all your knowledge!!!!! Thanks for the videos :)

@oneandonlyjaybee 9 лет назад

I am new to astronomy but as soon as I opened my new telescope and set up the EQ2 mount I knew the setting circles were not going to be used. They immediately looked too small and the pointers far too big and clumsy. Another entertaining video, thanks.

@ahmarsaeed6085 8 месяцев назад

These old videos are gems.

@thomthumbe 5 лет назад

I use mine quite often. I’ve never considered them as anything more than a rough indication of position when using my 6” Newtonian.

@MrAstrojensen 7 лет назад

The reason setting circles on most mounts don't work, is because they're too small, just like Robert points out. On my Zeiss mounts, they're more than 4" (10cm) across, are very finely and accurately divided, and work extremely well. I can use them to do accurate polar alignment with in the daytime and find stars and planets in the daytime sky. If manufacturers would take the effort to make large, accurate setting circles (easy in this CNC age) and users would take the time to learn how to use them, then users would find them to be very useful and quite accurate. It's actually not difficult or involve math.

@RocketPlanet 7 лет назад

Hi there, well said - I agree. The manual mounts I have used (and still use!) have circles in the 6" to 8" range (15 to 20cm) and in fact the last time I designed a large EQ mount with setting circles of any kind (for Broadhurst Clarkson & Fuller, England) they were nearly 11" (28cm) in diameter. One of my chief objections is not just the lack of efficient accuracy - that can be fixed as we have both mentioned - its the fact that you need to dump so much light on them to be able to read them accurately - and this process can be inimical to the needs of good dark adapted vision and thereby good deep sky observations. But that probably says more about my eyesight than I care to admit. Thanks for posting. KR RJD A&NTV

@danielankuda3436 7 лет назад

How to use setting circles on a small telescope (and why they DO work!) Consider one hole in a round of golf as an analogy: You eyeball the green and the flag off in the distance, Use a driver to get within reasonable distance of the green, Use a long iron to get closer to the green, Use a short iron to get on the green, Use a putter to sink the ball in the cup. When using your telescope: Point your scope towards the constellation that contains your target (eyeballing), Use the setting circles to get within reasonable distance (driver), Center the target in your finder scope (long iron), Center the target in your telescopes lowest magnification eyepiece (short iron), Center the target in your telescopes desired magnification eyepiece (putter). For most beginner/amateur astronomers, the finder scope offers a 7 to 5 degree field of view which is more than large enough for the target to be visible within the finder scope as long as the mount is reasonably level, has a reasonably close polar alignment, and the initial setting of the circles is reasonably close. Easy enough to use the dec and RA controls to center the target. This video did a nice job of showing how to get the circles reasonably close. Not sure how to level the mount, how to polar align, or how to use the dec and RA controls for centering? There are videos available for each of those. If your target is centered in the finder scope, the target will be visible within the telescope field of view offered by a low power eyepiece as long as you have a reasonably close alignment between the finder scope and the optical tube assembly of your telescope. Again, easy enough to use the dec and RA controls the center the target. Not sure how to align the finder and the OTA? Yup.....there are videos available for that too. If your target is centered in the low power eyepiece, the target will be visible within the desired magnification eyepiece. Once again, center it with the dec and RA controls. That might sound like a lot of steps and effort to the inexperienced, but with a little practice it can all be done within minutes.

@RocketPlanet 7 лет назад

Hi Daniel and thanks for taking the time to make a useful contribution - and I think with better than starter level instruments there is much to recommend in what you say. However, for folk grappling with a typical starter telescope it would be only fair to warn them that they may encounter much frustration if they follow your golfing schema. On the whole I like your analogy but it doesn’t really capture the situation that most small telescope users will actually encounter when they try to use the small diameter setting circles found on their instruments. The main problem with your image is the high visibility of the pin or flag showing you exactly where the hole is located. This does not correlate well, if at all, with the naked eye invisibility of most deep-sky targets. The wide approximation that is the blight of small circles offers no clue to the observer whether he/she is N, S, E or West of the target. Appealing for the help of the finder scope isn’t going to play out either as 1) where fitted, optical finders on entry level telescope have too low a light grasp to show more than a small handful of targets in a way that is useful to the inexperienced observer (and we need to remember that this is who we are talking to). And 2) modern starter telescopes are, in the majority, fitted with red dot finders. And where a red dot finder is too expensive a truly useless 6x20 optical finder is often fitted (peering through a drinking straw would be more use!). I think your advice can be followed if you have > 75mm diameter circles on both axes and a finder scope of not less than 50mm aperture. And I’m afraid that will exclude most people new to the hobby - so your Golf Club is going to be rather exclusive with mostly experienced players well into the hobby and still not many of them either. Thanks for giving me the opportunity to clarify why setting circles really don’t work for the majority of new, and inexperienced, telescope users. KR RJD A&NTV

@danielankuda3436 7 лет назад

In my analogy, you are not initially looking for the pin -- you are looking for the green. That makes quite a difference in the process of successive fine tuning of your target. The normal human eye has a limiting magnitude of 7. Under the best of circumstances, that puts 45 Messier objects within your grasp without star hopping. A 6x20 finder is indeed a miserable little instrument, but it has a limiting magnitude of 8 and a decent field of view -- your target can be expected to be within the field of view, even with coarse setting circles, and offers a full magnitude difference in light grasp making a faint fuzzy actually recognizable AS a faint fuzzy. A red dot finder has a different set of challenges. Given that it has no magnification, you need to know a reasonable starting point for the dot. Again, even coarse setting circles will give you a good head start. During the times that I have worked with beginners, the mere concept of star hopping made them want to sell their instruments. On the other hand, the concept of successive fine tuning made sense to them as a good start and many them did eventually learn how to star hop. Instead of ignoring the tools that were available to them with the kit that they had bought, or perhaps even walking away from the hobby, they learned to make the most of what they had and learned to work within the limitations. You and I can agree to disagree on the overall usefulness of the setting circles on entry level scopes. I suspect that we can both agree that the manufacturers of those scopes have probably done more harm than good in the amateur market due to the habitual over-promise of performance. Cheers!

@paulkazjack 5 лет назад

@@danielankuda3436 superb!

@RocketPlanet 5 лет назад

Hi again Danial, you make some interesting and useful points and I think viewers would do well to reflect on what you are saying - but with some provisos. You are referring once again to the mythical telescope user who has ideal observing conditions. Most observers (World = 55% UK = 83%) live in urban conurbations and will be lucky to see 4 or 5 Messier targets - not 45. The typical 6x20 finder employed by Sky Watcher, Meade etc, alas, has a limiting magnitude closer to 7 and an equally wretched field of view. This may seem like quibbling, correcting you to fractions of a magnitude - but it's important as it shows our different standpoints on this. Theory vs practical fact. My guess is you haven't seen many Chinese 6x20 finders - if you had, you wouldn't have reached for one as a support. The typical 6x20 finder does indeed have a single glass lens measuring 20mm in diameter, but the credit ends there as it usually has a black plastic disk with an 8mm oculus (like a washer only black plastic) positioned immediately behind the objective (on eyepiece side). In similar finders fitted to telescopes made in Japan in the 70s and 80s this disk or oculus was a conventional baffle correctly positioned midway down the OTA to improve contrast at the eyepiece. Due to a bizarre phenomenon that consistently affects people who copy things rather than actually originate them (or at least understand them) after a while the baffle slid down the tube and was routinely, and incongruously, positioned as a aperture limiting oculus immediately behind the lens. The situation now is so dire that in many cheap instruments, the finder has this oculus actually moulded into position almost touching the lens. In this position it has the effect of suppressing chromatic error - and the manufacturers assume (erroneously) that this is what it is for - and in a sense, definitionally, they are right. It is so, because they say it's so. But they did not originate the product and they do not understand what they have copied (there are many things like this on modern telescopes, equally tedious, and it is caused by an industry that copies first and understands second). A nasty side effect of the limiting oculus is a reduction of the limiting magnitude - in a way that significantly disadvantages our neophyte deep sky observer. In the end, for me, your prescription makes too many theoretical assumptions that simply won't play well for the user of a typical (300 USD 225 GBP 270 EUR) starter telescope. Your dismissal of the red dot finder is hardly fair either I think - the starting point is easy to establish during the day and needs little or no critical judgements. I'm sure, when you are there supervising hands-on, so to speak, you method does achieve the favourable results you suggest. I've had a very different practical experience - and it makes me very cautious about recommending circles to new users who are going to be in their gardens with a new telescope. I'm never going to recommend to new users that they struggle with small imprecise circles that they will need to pour loads of light on just to see clearly (thus defeating any hope of seeing a faint target) and they will need to develop a too subtle gamblers instinct, rather than a golfers, to find the target. Thanks for a polite and measured discussion, a rare thing on RU-vid. KR RJD A&NTV

@williamdunson7163 4 года назад

great explanation

@RocketPlanet 8 лет назад

The Internetwanderer. Well you are quite wrong on the first parts of your assertion - and I’m hoping that may weigh in my favour on the last element of your post as well. Many people in the UK call that ‘asterism’ (it’s not a constellation BTW) the Big Dipper, not because of our cowboy roots but because, like much of the globe, we are strongly influenced by US culture. And secondly, if you are going to make a habit out of taking abusive swipes at people (and my wild guess is you do) it will help your overall standing if you do a bit of research and try to get at least one thing right. KR RJD

@martinda7446 5 лет назад

I think the Internetwanderer wandered off! Sounds like he was dipped into a fresh tin of bullying, rudeness and ignorance. I just discovered your channel and have been watching it all night. The V2/A4 turbopump extravaganza was the first video I watched. I think that may be the finest historical/technical piece I've seen that wasn't produced by a gigantic professional crew costing a fortune. Quite remarkable.

@martinda7446 5 лет назад

Oops... I was just offering support after a rude unnecessary comment. Edit..That you got three years ago ha, ha Oh well. And now I sound like a nut.

@polygondon 7 лет назад

You lot make some of the best Amateur Astronomy videos on RU-vid. Thank you!

@xmanhattan 8 лет назад

Excellent presentation!

@InconsistentTechDad 6 лет назад

Honestly thanks for this video. It makes me feel less like it's my fault for being a tad frustrated with the setting circles on my EQ1. Edit: I know it's something that can be upgraded. I have JUST recently gotten into this amazing hobby. Your videos have been extremely helpful along the way :)

@robinj.9329 11 месяцев назад

I've been using equatorial mounts, with "setting-circles" since the 1960's. And IF YOU SET UP YOUR MOUNT CORRECTLY, and adjust the circles, they work just fine! Mine ALWAYS bring the object into the view of both my finder and a low power eyepiece in the telescope. If everything in in correct calibration? Your nearly always "centered" in the scope OR nearly so. BUT, and this is important. Everything does need to be set up with skill, care, patience AND PRECISION !

@tnathe 11 лет назад

great vid, as are your others! Thanks, I learned a LOT!

@hostesstwinky Год назад

Excellent explanation. Thank you!

@Nanaki83 12 лет назад

Got the EQ1 mount myself, and not used it for the 10 years I've had the telescope for the very reason you describe. tried at the start to figure out how to do it, but alas, i gave up. soon I'm to buy a new one with a Go-To, and can't wait to be able to find stuff I'm looking for without trying to fine tune a tractor through the eye of a needle. love your videos, highly informative even for veterans. subscribed and loving it!

@ktsvetkov 11 лет назад

I was sure about this problem with the setting circles, but now after I heard it from you, also, I'm absolutely convinced :-). Thanks!

@AgniesMTDronesandPixels 4 года назад

I really liked the way you explained the setting circles. Probably the best tutorial so far. I disagree, however about the accuracy vs. the purpose. Most beginners telescopes (and if you are using EQ1,2 or 3) you are rather a begginer) come with 650 -1200 mm tubes. I have 1000mm refractor and it gives me FOV of approx 2 degrees. Beginner’s “fuzzies” are usually bigger than this, so I actually find my telescope slightly to narrow. I took nice photos of Orion, Pleiades, Carina and few others. To see any of the smaller ones, you actually need a bigger telescope, and bigger telescope completely excludes any of the small mounts you mentioned. I would say if you happen to have smaller mount, get a wider scope and make proper use of what you have. Leave small fuzzies for when you have better equipment, bearing in mind that on top of the mount and scope, decent camera with filters will also be needed.

@ItsMeScareCro 10 лет назад

Thank you so much!!! My star gazing has been really frustrating lately. :( I hope it's not cloudy tonight!

@friend610 3 года назад

was it cloudy that night?

@langy011 10 лет назад

So you do a video titled "How to use setting circles on a small telescope",. get half way through on how to set it up and then decide to slate the whole thing because it isn't accurate and then don't finish the subject. Why not call it "Why not to use the inaccurate circles on a small telescope". At least you could have finished on the setup and demonstrate how to use it. Even if they are not accurate it must be like using a satnav to take you to a post code where you then search for the final location. Once you have them setup you should at least be able to quickly point the scope to the required location within a few degrees to help find what you are looking for.

@RickHC13 10 лет назад

correct, that is my point, very informative video but suddenly guess what, it is not worth the try. actually around min 16 is where you get the real thing. Also the telescope with the small circles, I have one of those and they are supposed to be very amateur, they even say you cannot see deep sky objects with it, so perhaps they don't get too HD on the circle since the whole gear is not supposed to be that pro. Anyhow, I ended up having a bitter-sweet feeling after watching this... And BTW, it should have taken around 8 mins tops...

@alastairleith249 6 лет назад

Also, added to which, many of my colleagues have tried using these and said they IS accuracy in their use. I agree though, i would have at least have gone on to show how they could be used even in faith in accuracy in their use is questionable

@RocketPlanet 5 лет назад

Hi langy011 - No, it's nothing like your analogy I'm afraid. The idea of the video was to short-circuit the waste of time and frustration caused by trying to use small setting circles on typical starter telescopes with equatorial mounts that just do not work. It's not just that they are inaccurate but useful like your postcode analogy suggests, it's that they actually baffle and hinder your best efforts to find the target even if you get somewhere close to it - and this is because they force you, because of their small numbers and poorly defined indicator lines, to pour vastly too much light on the scale so that you can read it, thus destroying the very thing you need to find the target in the first place - namely good dark-adapted vision. KR RJD A&NTV.

@KC9MDO 9 лет назад

Not entirely correct on one or two points. If you use an eye piece that yields a true field of view of 2 degrees in the scope being used then the the spacing of the lines in the scale, at 2 degrees, mirror your field of view. therefore you can get close enough to the target to search for it visually. Switch eye piece to a higher power and enjoy.

@RocketPlanet 7 лет назад

Hi there. Maybe you are unaware that far and away the majority of starter scopes in the shops (the kind that people viewing this video will typically posses) have actual fields of view (AFOV) in the range of 1 to 2 degrees with a typical included 25/26mm eyepiece (an attempt to average by popularity/sales would cluster in the 1.4 to 1.7 degree range). For the majority to achieve 2 degrees AFOV they'll need a 30 to 40mm eyepiece - and this is hardly an ideal choice of ocular for urban (most folk live in cities or near them) viewing of deep-sky targets as eyepieces in this longer focal length range tend to reduce vital contrast and lighten the sky background making deep sky (DS) targets harder to detect - especially for the inexperienced user (our target audience after all). And besides,widening the AFOV still doesn't address the fundamental issue of the lossness and poor repeatability and general lack of useful correspondence between the SC definition of FOV centre and the telescope's actual FOV centre. We'll stand by our advice to bypass the SCs found on small scopes and make the most of the included red dot finder, or buy one, and star hop to DS targets. Thanks for your message and the chance to extend the dialogue. KR RJD A&NTV

@DeuteriumTech 3 года назад

Can I just say, this video is very helpful!

@Narnian78 8 лет назад

I have a little Sky Pointer which I purchased from Sky and Telescope magazine about twenty years ago. It is somewhat useful for pointing towards an object in the night sky but only for the general direction. The pointer is like a miniature equatorial mount with setting circles but without the telescope. There is also problem with keeping the pointer level to have it work with accuracy ( there is the same issue with a telescope). I think the little gadget is more useful for teaching people how night sky works than for finding objects. )

@lt3533 6 лет назад

Excellent video! Thank you very much :-)

@marianopicco 12 лет назад

Thanks, very informative. I guess it's how I had figured, they're only general guide for finding something, I'll have to learn how to star-hop. Looking forward to other beginner tip videos

@cortexbomber 11 лет назад

Great Video ..... loved the easter egg after the credits! Genuine LOL!

@southernexposure123 2 года назад

I'm a novice to astrophotography so I was looking for a useful illustration. My work background already allowed me to understand the level of innacuracy of the ring markings and the static marks on the mounts. I knew that even after using the circles I'd ultimately likely have to scan the sky at least a little to find my targets. Still I wanted the full explanation because I don't understand. Making the title read as it did I was disappointed that about the middle of the video I was told that trying to use the circles was useless because ratios of the math of street widths on a street map makes setting circles a useless exercise. Frustrating. Oh well I'll keep looking for a video where the explanation is more fully explained. As a side note I recently dealt with the Orion company and found that experience also frustrating.

@MountainFisher 2 года назад

I've been hearing that so I avoided their products. Bought an Explore Scientific and man they were quick to help me set my EQ mount up solid as it was a bit shaky.

@raygun6271 4 года назад

Very useful explanation! Also enjoyed the Benny Hill sequence:)

@MladenMijatov 12 лет назад

One additional problem with RA scale is documentation which for my, SkyWatcher, telescope was completely wrong. Image was showing 0h 0min while caption was saying that image shows 8h 20min. Took me a while to realize this. :D

@gee6607 4 месяца назад

You are the best at all things ASTRONOMY

@superlinux 5 лет назад

you are making me homesick to Australia now. I studied my masters there. in Cairns.

@navigator9940 4 года назад

Is there a reason for using Dubhe over, say , Polaris? You can lock in coordinates using any catalogued Star right?

@jefflucas_life 7 лет назад

So setting circles can be used as a reference point? I have EG4, my RA setting circle rotates but not my Dec setting circle, its fixed position. What throws me off, the starting zero position setting isn't centered for north or east, long/lat. I am not sure, if I should use a small hex nut rotate the the DEC to reference meridian line / zenith but Ill ask celestron. Just got off the phone, the DEC zero setting should be facing true north, like your NCP, mine was off by 10* with a lock nut, which I am told can be adjusted. I asked about RA, its supposed to be zero indicating 90* up.

@naziraaidaralieva6801 6 лет назад

Very informative excellent video thanku

@aalhamed5479 6 лет назад

Thank you so much Sir .

@MilanKarakas 6 лет назад

Those rings are good enough to get me close to the DSO of interest. After that, plate solving (I am using AstroTortilla), it is easy to move the scope at the target. My APS-C sensor is 1.47x1.11 degrees, and by using rings on my EQ3-2 gives me no more than two frame width/length off after indexing and initial rough finding. Then simple fine adjust and plate solve again until object of interest shows clearly on long exposures. For visual, if you can't see group of stars, then probably you can't also see the DSO either.

@naguok 7 лет назад

excellent explanation

@mikegordonbrasov161 2 года назад

Excelent! One question please: I just bought a new skywatcher120/1000 rig with manual equatorial neq5 and I'm still learning the equatorial (before it had a 70mm with altaz mount. Once I managed to put it in parking position (orient the tripod to the north with a quality compass, level the tripod , level right ascension and level declination and adjust latitude of Madrid), can I consider that alignment is good enough to visual moon and planet by using the A.R. manualy slow motion to track it ? Even if it is fake alignment? because sometimes you want to see the moon during the day or because there is something building, that does not allow you to see the polar. And if i lose the objet, can i correct the declination too? thank you again

@breakspirit 12 лет назад

This video is great

@davehayes6421 10 лет назад

Obviously the larger the setting circles, the more accurate they will be. I''ve been using the large setting circles on my small fork mounted 4" Schmidt-Cassegrain for years, with very satisfying spot-on accuracy. But instead of demonstrating such a great system on a small scope (as I expected from the title) you show a German equatorial mount (these are nearly impossible to polar align) with tiny setting circles and coarse indicators that are nowhere near the scale, then explain how impractical the whole concept is? Now there's a man who wants to sell you a computerised goto mount.

@GeorgeSpan 7 лет назад

The whole approach sounds correct, but for a small telescope like TAL-1 used in this example things are not that complicated. These circles are only meant to provide the neighbourhood of a star and not the star itself. If the quality finder scope is perfectly aligned with the main telescope, then one has plenty of field of view to locate the star in demand and simply bring it to the cross-hair centre of the finder scope. Then it is certain that the star appears in the eyepiece too. I suppose that is why finder scopes are for, and many times more than one with various magnifications :-).

@donaldkasper8346 2 года назад

From the whole sky, the indicators get you to 2 degrees of your object, then the viewfinder with star chart gets you to the star. The smaller the arc field of view, the larger the graduated ring has to be. It is not 8 inches, it is relative to the telescope field of view.

@timodell5728 Год назад

RE: your road map- If the lines designating the route were printed to map scale across highway( if they could be) you could hardly see them. Scale along the route is probably reasonably accurate.

@RocketPlanet Год назад

And that's the point. To be useful the divisions on the circles need to be so fine you would need a powerful magnifying lens to see them. But, much worse, you need to pour light on them to be able to see the divisions, and in the process reduce your ability to see the faint deep-sky target you are looking for in the first place. Small setting circles don't work, even large ones can lead to poor ourcomes (loss of useful nightvision sensitivity). KR A&NTV

@catstercatster 12 лет назад

So its not just me! Thanks for clarifying this - I really thought I was just being thick. As usual your video goes right to heart of things! Maybe you can do a vid about why the economy doesn’t work now? Love the Benny Hill bit btw.

@appie640 12 лет назад

Can you please review the Celestron CGEM mount?

@RocketPlanet 12 лет назад

@AmusingYeti Hi, the software featured in the video is Stellarium - and it's available as a free download - just Google it. Hope this helps. KR A&NC

@richarddempster 8 лет назад

so the dials on my eq3 mount with the skywatcher 127 are not worth using and I should just us the polar aligning scope to set my mount up, sorry for the question new to astronomy

@billruss6704 2 года назад

I noticed that the slow motion knob makes one revolution per degree. You could put ten evenly spaced marks on it to improve accuracy by a factor of ten.

@Tbonyandsteak 4 года назад

Soo how do you tightening a woobleling equatorial mount?

@Cityj0hn 10 лет назад

I was rather looking for a video explaining how your current location and exact time can be used to set your setting circles up without a reference point in the sky and then using them as an Absolute rather than Relative measure.

@chrismartindale2139 5 лет назад

me also

@Chikokishi 11 лет назад

On my hour dial i have 2 sets of numbers. one on top counting up to the left and one on bottom counting up to the right. when you say to "set your hour" ... which direction do i go? Iv never been able to find this answer.

@szaki 8 лет назад

Yes, setting circles are small, but all it needs to do is to get close to the target object. Long time ago I played with setting circles, found out one needs a wide field super finder too!Now days I own a Vixen GP DX EQ mount with Sky Sensor goto, hole EQ set up is super accurate!Goto systems are very cheap now days, even less expensive mounts come with it, but even quality mounts under $1000 has it too.

@user-FokitisManos 5 лет назад

Very instructive video. Why the manufacturers donnot add a vernier scale?

@lawrence8299 7 лет назад

I have a 4 inch reflector of F/4 in a table top "Dobsonian" style mount which I added setting circles (printed on paper using laser printer) to it's base (almost 7 inches diameter) and also to the altitude axis (only 3 inches diameter). With this and a low power eyepiece I can get rid of my red dot finder (bad because no magnification) and use a mobile phone app to retrieve the ALT/AZ coordinate - that works very effectively and almost locate anything in 10 seconds. WIth some land objects (e.g. tip of a pole) I bookmarked it's coordinate earlier, I can locate bright planets like Mars hours before Sun set.

@mickeysizemore3515 3 года назад

Hi all. I'm hoping someone can help me figure out how the declination works on my, new to me, CG-4 mount. Just got it a few days ago from the local astronomy club. The declination has two pointers or arrows above the degree ring. One arrow is cast and the other one has a metal tape piece with an arrow. Both are pointing down to the ring. The ring goes up to 90 degrees and repeats 4 times. When I have one arrow set at 90 degrees the other one is at 82 degrees or so. I've looked both online and in the owners manual. Nothing explains why this is so. New to the hobby and would like any suggestions or explanations. Thanks.

@BC_Airsoft_Photographer 9 лет назад

how do I input the DEC and RA to telescope...??

@MountainFisher Год назад

I use a precision Goniometer or angle finder on my telescope to get the Declination of my target and the setting circles just get me into the ballpark. Now I can use Polaris as zero, but Stellarium has an Azimuthal grid that tells you your target's altitude from the horizon or you can calculate your target's position from zero at Polaris.

@fvmuijen 6 лет назад

Where is the movie about the red dot finder solution?

@Chlorate299 3 года назад

Glad it's not me then... The awful setting rings on my Orion EQ-2 coupled with the spotting scope with incredibly short eye relief make it so difficult to find objects in the sky, whether they're visble or not.

@hovlandbound 10 лет назад

Thanks you. Good info. I was hoping there would be an easy way but I guess not. :)

@knight654654 9 лет назад

Heres what I still don't understand, yes the stars are fixed; but they're still moving across the sky due to our planets rotation... So how is that RA and DEC coordinates can locate the star?

@knight654654 9 лет назад

Gordon Walker The scope must have some sorta tracking mechanism, or some kind of way to set the time right? If it locks onto RA and DEC it must have some sorta clock drive to keep it pointing at the coordinates? Unless it requires manual movement after you align it with polaris and point it at an object.

@knight654654 9 лет назад

Gordon Walker Okay well, thanks for trying to explain anyway, stellarium is great! :)

@brendanobrien7746 9 лет назад

Gordon Walker

@2resist36 9 лет назад

knight654654 The reason is this.... Think of RA and DEC as comparable to longitude and latitude respectively. Comparable but different, particularly in the case of RA. The point of zero longitude is defined as a point on Earth itself, thus zero longitude rotates with the Earth and is useless for defining fixed points in the sky such as stars. However RA is significantly different from longitude in that the point of zero RA *is* defined as a fixed point in the sky, the First Point of Aries. Every other RA coordinate is measured relative to this fixed point in the sky, hence RA coordinates do not change as the earth rotates. With regards to DEC, the reason those coordinates do not change, is because although the Earth rotates, it's poles and equator remain in a fixed position. DEC is a measure of how far away something is from the equator, or technically speaking the Celestial Sphere's equator.

@jinzai1962 6 лет назад

Maybe you are suffering from the same thing I tend to suffer from -- your point of view is located on the moving part, so -- you tend to hold onto the notion that the stars are moving. From our POV, the RA and DEC 'appear' to move, but -- it is actually our POV that is moving. The RA "movement" is the Earth's rotation and the DEC "movement" is the Earth's ever changing tilt along its axis of rotation. Sometimes, it is difficult to get outside of my own head.

@Megajam24 4 года назад

Fenton.... You absolute legend😂😂

@NatarajanGanesan 7 лет назад

I just got my EQ-1 mount and am a beginner. In so many words you have basically rendered the circular scale as showpieces :) . To a beginner like me that's a bit disheartening :P though I wonder if a couple of adjustments to that scale would help. 1) Firstly, besides the magnification part of it (in smaller mounts), I was thinking of some vernier attachments to the main scale reading. Probably too much of an ask for an already small scale 2) Modern smartphones with their inbuilt gyroscopes, can be (I feel) pretty useful if attached properly to the mount. Some neat little apps give the exact equatorial coordinates as you point to the celestial object.

@MattSchulze 5 лет назад

Depending on the size of your telescope those circles will still get you in the vicinity and a little hunting eat-west or north south will usually get you object.

@paganphil100 Год назад

I have the same problem with the Latitude scale on my EQ mount......my Latitude is 53.8 but the relevant part of the scale goes from 40 to 60 with only a few divisions between them so its not possible to set it accurately 😞

@jack002tuber 7 лет назад

I had to stop when you started measuring the road width. Maps make them like that so you can see them.

@RocketPlanet 7 лет назад

Well quite. But maybe you should have stuck with it - as that was the point rather. Now measure the actual thickness of the index lines on a typical small setting circle, then corelate or convert that measurement to arc minutes in the sky (pretty much as we did - tongue in cheek - for roads) and you'll understand why small setting circles don't work well. A&NTV

@EvenTheDogAgrees 5 лет назад

Honestly, the explanation with the line thickness is not exactly complicated. I understand you used the road analogy to make it easier to grasp for folks who have trouble understanding the difficulty in trying to make precise adjustments with imprecise measuring tools. But the analogy is flawed, none of the bits in concept A match up with the "equivalent" bits of concept B, and in the end I think it's just more confusing for people who already have trouble grasping the concept. EDIT: that said, I still enjoyed the video, and the others on this channel. Thanks for going through all the trouble of shooting all of this and putting that info out there.

@DavidRice111 7 лет назад

Ha Ha! When he checkes the map scale of his road I get shades of Benny Hill!

@johnbyrd9152 10 лет назад

Where Can I purchase setting circles? Or, How can I make a set?

@GaryMCurran 9 лет назад

This video was done in 2012. Where's the video on the Red Dot finder and how to use that? Please.

@pault5947 7 лет назад

Yeah, my thoughts too, guess he forgot/couldn't be bothered?

@DavidRice111 7 лет назад

Unnecessarily snarky there, paul.

@johnjriggsarchery2457 5 лет назад

Align it with the telescope during the day, then locate your intended object on a good star chart, and find your object in relation to the stars in the sky. Figure it out, it's simple.

@ptanawong Год назад

why are there two sets of R.A. setting circle and why do the numbers of each set run oppositely?

@CraigRison 2 года назад

I probably didn't watch or listen close enough to hear you mention the importance of first having (or getting) an EQ mount polar aligned? I believe that is necessary for setting circles to work for two objects with any significant distance between them to have any accuracy (within the limited visual resolution of it's diameter as you explained clearly) the mount has to be reasonably polar aligned? In other words after you have set the rings to coordinates from the chart/stellarium for the first object and then you move the scope to another object far away from the previous object the setting circles will be off proportionately relative to the amount that the scope is from being polar aligned - so the circles will have less accuracy the further we get from our original object - way beyond the visual limitations of the diameter of circles themselves?

@ellk1991 12 лет назад

Thanks a lot for the video and heres me thinking i must learn how to use them annoying things :)

@michaelschnittker7388 5 лет назад

Circles only work if your polar axis is aligned with the celestial pole. You can look up your latitude on Internet or using your IPhone and set the latitude the up and down angle of your RA polar axis that way. East/West alignment is done by setting your declension circle to 0 when the telescope is parallel to the polar axis and leave it alone from then on forever. Then find two or more bright stars in completely different parts of the sky. Lock the dec axis at dec coordinates of first star and sweep in RA polar axis until it is near the star then move the whole telescope until it is in view of finder and telescope. Dec never changes with stars, it's RA that moves like a giant clock in the sky. Don't worry about RA numbers yet. Then do the same for another bright star in opposite part of the sky, get its dec and move the telescope to that number and the star should be near in the finder. If you do this over and over you will align the axis properly. You have to constantly change the RA circle to reflect sidereal time unless your clock drive does it for you but you can set it at any time easily by looking at a bright star and setting it to the RA of that star. It'll be good for a several minutes at least. After a while you can set up in minutes, you have the dec numbers in your head for Sirius, Vega, Arcturus, Spica, etc., make a list.

@rodneyjohnson4794 3 года назад

love the boots randolph music! almost missed the benny hill- type fast motion footage. i'm more of an aybs?- type of guy. sometimes the truth hurts. in my case ~$100 worth of crude mount, the eq-1. its not actually a bad mount, just....imprecise, apparently as many/most on the market are. precision is expensive. my scope fortunately isn't a deep sky model; an orion st80, so i don't expect to see infinity! i won't get a motor since i have no interest in ap. for what i CAN see, the 2 slo-mo tracking knobs are adequate. i have 3 star applications on my amazon fire tablet and they help. thanks for an honest lesson.

@Chlorate299 3 года назад

I took my EQ-2 apart recently and I have to say they must be making a killing selling these damn things. I can't find anywhere near $100-200 worth of value in them at all, there's not even any bearings inside to speak of, just painted pot metal on painted pot metal surfaces. I did find that you can improve them greatly by taking them apart, cleaning off the horribly sticky grease they come with, lubing it up properly and snugging everything down a bit tighter than they did at the factory.

@josephnaja Год назад

Can't you use Polaris to set your circles then go to your targets from there?

@tubedude54 7 лет назад

Get a mount that has at the very least digital setting circles and the 'problem' is solved! Now you can turn the scope and watch the readout to get you to an accuracy in line with how much you want to spend. Many yrs ago... and I mean MANY!!... I had a Sears refractor with and equatorial mount. The setting circles were pretty much useless because of their size but the biggest problem was the RA circle was scribed BACKWARDS! Later on I ground and polished an Edmund Scientific 6" mirror kit and built a 6" reflector, my then pride and joy till I did a 12.5" yrs later, and mounted the 6" on an Edmund equatorial mount that had 'nice' circles on it. But the RA circle was mounted to the mount housing and was stationary! It didn't follow the object you were centered on which made you have to reset it before proceeding to a new spot!! At 12-13 yrs old these were things that drove you crazy as to why things didn't seem to work as they should!!

@RescueMedic 5 лет назад

Whoever reads my comment please answer my question. On a Celestron powerseeker 70eq where are the mm markings on the focus to be able to tell that you're at 35 mm? Focal length of 700 divided by 20 mm lens equals 35 mm. I'm just asking how do you adjust to the mm length on the focus?

@RocketPlanet 5 лет назад

Hi there, Swedes normally greet this kind of question with the phrase 'Good day, axe handle!'. It means the question is couched in terms that render it unintelligible or at least unanswerable. The mathematical operation you refer to is simply used to derive the magnification of the telescope focal length and eyepiece combination - so not 35mm but 35x. There are no 'settings' required for the delivery of the magnification function, and there are no 'markings' requiring any kind of alignment. Simply look into the eyepiece, at a target, and adjust focuser until the sharpest image is seen. I assume you don't have an operators' manual for the instrument. Can I suggest you either visit the importer's website and see if you can download one, failing that - write to them and ask for one? They will generally oblige if you ask nicely and maybe even send a large self-addressed envelope too - to prove you're nice. I hope this helps. KR RJD A&NTV

@anthonysacco2276 3 года назад

Thank you :-)

@bigwhiteyeti 3 года назад

Do no setting circles have Vernier scales on them? These could actually make them useful and accurate to fractions of degrees.

@cosmictywlite 9 лет назад

Hello there,So setting circle`s are no good if there are under 8 inch" in Diameter,Does that make the Setting Circle`s on my HEQ5 Mount unreliable, thankyou

@jeffmoye 8 лет назад

+cosmictywlite I think the point is that when you are using high magnification, the angle of view is teeny tiny compared to the precision you can get with small setting circles. So if you are looking for a small object, it is very easy to 'miss': the tube will be pointing in roughly the right direction, but not precisely enough that your target will be in view. For example, if you have a 180mm maksutov-cassegrain telescope (2700mm focal length) and a canon eos350d camera, your field of view is 28' (just under half a degree). If you set the telescope a quarter of a degree out, the centre of your object will be outside of your field of view. Now each hour of RA accounts for 15 degrees of movement of the tube (24 hrs = 360 degrees). On your HEQ5 setting circles, you only have 6 small graduations per hour, so each graduation is 10 mins of ra, or 2.5 degrees of movement. So to guarantee your object is in view in this scenario, you need to be accurate to within one tenth of a small graduation. Good luck with that. Your best hope is to be within half of a small graduation, or 1.25 degrees - just about what you get with a scope with a 1000mm focal length and a 28mm eyepiece

@cosmictywlite 8 лет назад

Thanks a lot for the Detailed info about setting circles,I have good guide scope now ,so that helps me Track the Night Sky a lot better. cheers Jeff

@MADHIKER777 Год назад

Loved the Benny Hill scene 🤣

@bernym4047 6 лет назад

My instrument has a vernier scale on the RA circle for improved accuracy.

@sssukaPSN 12 лет назад

I have that small 4.5" telescope with the eq mount and I never use the mount like it should be what I do is find an object that I want to see look at the surrounding stars and slow make my way to the Target. It's much better and you learn more.

@jinzai1962 6 лет назад

Dang! It seems I've missed out on another across the pond dustup. That's okay -- like the trains in Japan, another will be by directly and on time. So, about the video...very nice bit on a piece of nostalgia from my childhood, I actually envied my friend that had a GEM with setting circles and slow motion controls. Thanks for the therapy. The Benny Hill reference was not necessary, however -- thanks for that, as well. The field exercise afterwards was pointless and that is what I liked the most about it. I have a Meade ETX125 -- the Observer -- not much better than the various Tasco and Meade scopes I have owned in the past -- Except that I am 55 now and this instrument is not all bad by any stretch. It annoys me that it "looks" like a great instrument, has much of the same capability as Meade's "real" telescopes and they simply leave everything "as an exercise to the consumer". Through exhaustive and diligent research (i.e. Googling for literally hours on end...) I have managed to get the instrument performing to my satisfaction and it appears that it can guided by PHD2. I have decided on a Celestron AVX and Explore Scientific ES80CF as my mount and astrograph, but -- Meade has me in a foul mood over the ETX125, so I am kitting it out to image clusters and doubles -- despite the fact that it is woefully inadequate for that. To that end, I have purchased the rest of my AIS ahead of the mount and scope -- QHY163C, QHY mini guidescope, QHY5-II guide camera and QHY Pole Master. I will likely defork it next spring and use the AVX, but -- again, I am stubborn -- and Meade is just flailing about now -- about to disappear, I think. I enjoyed this video enough to subscribe -- it confirmed lot that I had discovered decades ago and I now what a "B road" is. I am now off to watch more of your work. Cheers from Iowa.

@Visium1 3 года назад

you can use the setting circles to bring you to bright objects, then star hop to the dim objects from there. simple.

@RH-cf4ic 8 лет назад

Okay but as a beginner, I still don't understand how to align or use setting circles.

@RH-cf4ic 8 лет назад

***** Thanks dude!

@Subscriberswithnovideos-ms3ht 6 лет назад

Easy, point the 0° point by the beginning of the tripod at polaris. When you look up coordinates the first numbers are the inclination. The second number is a the rotation.

@rampike74 12 лет назад

They still might come in handy if you are looking for a, say, a 3-degree M31. (I like your chop-stick. :) BTW).

@modbnet 10 лет назад

BENNY HILL!

@robinj.9329 5 лет назад

The community of Amateur telescope makers way back in the 1930's right through the late 60's were able to make their own setting circles that worked just fine! Today with the manufacturers able to make so much money selling you these new electronic marvels, they have zero incentive to make or market a scope with real fine and accurate circles! BUT! You can still just make your own!