Rubbish at star hopping

[Merlin999]

We finally had clear skies last night so got my new 127 MAK out:hello2: We got good views of Jupiter but we did find it quite variable. We never saw the GRS but not sure if we should be able to from our LP garden.

We then decided to take a look at Albiereo. As the flashing lights in my eye condition make it difficult for me pick out constellations, it fell to my hubby to find the stars, while I was in charge of the Planisphere/Stellarium. With the naked eye he quickly found the summer triangle and could see a blob in the sky where he thought Albireo was. So it should have been a simple matter of pointing the telescope to the blob, yes?

Um, No. His first step was to point the telescope at Vega shining very brightly. I am sure you can all guess what the big issue was. Once he had the telescope pointed roughly in the right direction he looked through the Finderscope to see loads of stars with no way of knowing which was Vega. Eventually after a bit of trial and error, he decided he had worked out which one was Vega. The next step was to move the telescope down and across to Albireo which wasn't terribly far away. As he was moving the telescope however, again there were lots of stars and he was unsure how far he was moving the telesope in relation to to his target.

So an hour and a half later we gave up and turned back to Jupiter. It was a bit frustrating but we did get some nice views of Jupiter and some nice views of some stars we weren't actually looking for, but nice nonetheless.

So we have two issues that I am sure are not at all unusual:

1) You see a big bright star in the sky and want to point your telescope at it but your Finderscope shows so many stars you can't tell if you are pointing at it.

2) How can you tell how far across the sky you have moved when you want to hop from one star to the next.

I suspect the answer will be RDF/Telrad/Rigel, but I know nothing about these or how you use them, so any advice would be really appreciated.

[Ben Ritchie]

I suspect the answer will be RDF/Telrad/Rigel, but I know nothing about these or how you use them, so any advice would be really appreciated.

Yes

I use a RDF to find the right area of sky, and use the finder (if necessary) for the last bit. IMO Hopping long distances with just an 8x50 finder is hard.

So in that case i'd use the RDF to point at the centre of the summer triangle, where Albireo is, then look through the finder. You'd see it instantly.

[Merlin999]

Thanks Ben. Glad you found it hard hopping with just an 8x50, makes me feel a little less useless!

Do you think a Telrad/Rigel would be useful over an RDF? I have read the circles can be a good aid for judging distances travelled and that some maps will even tell you how many Telard circles to move by but not too sure how this would work in practice? Or would this just be overly complicated?

[Ben Ritchie]

Do you think a Telrad/Rigel would be useful over an RDF?

I think it depends on what you're looking at. I use the Rigel and an 8x50 RACI finder on my Dob, as i'm typically tracking down fainter stuff so i'll use the Rigel to find the general area and then hop with the finder. However, I also have two Baader SkySurver V RDFs - one in the observatory, one on my grab'n'go refractor - because in those cases i'm generally looking for brighter objects; alignment stars for the goto mount in the observatory, while the grab'n'go tends to be used for bright objects and/or low powers. In both cases a (good) RDF is fine for getting me close, and I don't have a magnifying finder at all.

So that's a long way of saying "maybe"

[Rossco72]

I agree with the RDF, but if you are using your finder and there are lots of stars and you aren't sure which is the bright naked eye star you are looking for, then you haven't found it! In your finder it will be glaringly bright and very obvious once you have something like Vega in the crosshairs.

[Merlin999]

So that's a long way of saying "maybe"

Thanks Ben. Sounds like and RDF may do most of the job for us. I'll have a look at RDFs and see how the cost compares with the Telrad/Rigel. Daft question, if I got a Telrad or Rigel,are they as easy to use as an RDF?

I agree with the RDF, but if you are using your finder and there are lots of stars and you aren't sure which is the bright naked eye star you are looking for, then you haven't found it! In your finder it will be glaringly bright and very obvious once you have something like Vega in the crosshairs.

Oh dear, does that mean I have to tell hubby he never found Vega after all?

[Ben Ritchie]

Daft question, if I got a Telrad or Rigel,are they as easy to use as an RDF?

Not a daft question at all. If at all possible it's worth trying out some of the options, as people have different preferences and it's a shame to spend £35 on a Rigel to find you don't like it.

In my experience the Rigel is slightly fussy about eye placement, but not at all bad and it's better than an equivalent-price RDF (The Baader RDF I have is great to use but also much more expensive than the Rigel). Can't speak for the Telrad, but I know a lot of people speak highly of them - I use the Rigel mainly because it was what FLO had in stock, and i've got used to it.

[pvaz]

In one word: Telrad

Since I bought one never had this kind of problems. I think the telrad is easier to use then a RDF and it takes standard AA batteries. Never tried a rigel.

[Rossco72]

The Telrad is good but it is fairly large compared to some of the others. I have used WO RDF (too bright), TV Starbeam (too expensive) and Telrad (a bit on the large side) I have also found cheap £10-15 RDF's difficult to use as they are sooo dim.

For a 127 Mak, the Telrad should be fine as the scope is a decent size.

[sn00p]

naked eye stars appear MUCH bighter in the finder than the other stars.... so yes i beleive the hubby needs telling :-)

[Merlin999]

naked eye stars appear MUCH bighter in the finder than the other stars.... so yes i beleive the hubby needs telling :-)

:)I'll pour him a nice glass of wine first!

Looking at FLO they have the Baader Sky Surfer III for £21,the Baader Sky Surfer V for £75, the Rigel for £35 and a Celestron green laser finder for £89. They don't have a Telrad but I can get that for £38.

Crumbs, haven't a clue. I know hubby can be a bit frustrated getting eye position right so as Ben says the Rigel may be a bit tricky. The Baader V gets very good reviews but is bulky and pricey. The Telrad is also bulky but also gets good reviews.

Would the Sky Surfer III (the cheapest option) be a good bet? Is it fairly easy to use? Our budget is limited but I would rather choose a good decent option that I will use for quite a while, than buy one and want to upgrade in six months, especially bearing in mind how rubbish we are at star hopping.

[Skills]

I have found the Rigel very easy to use, it's small footprint and light weight make it good for a smallish scope. The only problems I've had with it has been dewing but that has been effecting everything for me not just the rigel.

[Rossco72]

If you are going to do star hopping then the Telrad's field of view circles can be a great help in judging the distances.

[perrin6]

I think it just takes practice to get the knack of relating the finder view to the actual. You need to find a very bright star by sweeping with a low powered eyepiece, until it is in the centre of the field of view, then the brightest star in the finder will be where the telescope is pointed.

I dont bother perfectly alining the finder as I just remember where the telescope is pointed with respect to the crosshairs (a bit more difficult in red dot finders as I think they use mainly circles).

I find a 7 X 30 finder much preferable to a red dot finder as I can only see stars down to mag 4 with the naked eye and objects are much easier to locate when you can see stars down to magnitude 8 in the finder.

To find an object I mentally note shapes of star-formations, mainly triangles, on the map and measure dimensions in degrees and minutes and direction eg 'object (or next star-shape to hop from) is 1 degree, 20 minutes NNW of firsthop-off point. As I know how wide the field of view of my eyepieces are I can then skew the scope that distance from star hop-off points.

Alan

[Merlin999]

Thanks Skills and Rosco sounds like the Telrad and Rigel are both very good.

Thanks perrin6. Hmmm I'll talk to hubby to see if he feels he wants to try it again or whether he wants to get something to help him navigate.

Thanks for all your advice. Much appreciated,

[Rossco72]

You will find that many people actually do use both. An RDF to get in the right area and then an optical finder to fine tune. Both need to be well aligned with the scope first of course.

[PeterM]

I haven't used the Telrad but I've found the Rigel very useful for exactly the reasons you've mentioned. The Rigel is kind of fussy re eye placement but not in the same way as an eyepiece. The Rigel sits right at the objective end of the scope and you sight along the scope from the bottom. It should only take a second or two pick up the two red circles and then you can just point the scope at whatever you want. It does save a lot of faffing around.

The advantage vs a RFD is that you can use the circles to estimate distances but if you're really using it point the scope I'd imagine a RDF would work just as well. The only bad thing about the Rigel is that it looks cheap and plasticy.

[Merlin999]

The only bad thing about the Rigel is that it looks cheap and plasticy.

Thankfully I'm not a girl who is obsessed with looks! Thanks for that. Sounds like there are a good range of options to solve our problem. As it's hubby who will mainly be doing the star hopping, I'll have a chat with him this evening.

[Astro_Baby]

With an 8x50 finder it can be very hard work - in the end I bought a GoTo upgrade and had done with it

[ronin]

To star hop you need a decent field of view through whatever you peer. Hopefully not the actual scope, especially if it is the 127 Mak.

An RDF will give the biggest field as it is simply a red dot imposed on your own eye's field of view.

People find the different finders either work for them or don't. So someone saying xxx is the best is really saying xxx is the best one for them. I like RDF's others simply cannot use them.

Mel has the best idea, get a goto, and a long focal length eyepiece.

[perrin6]

I want to extol the virtues of the humble 30mm finder:-

I think anything bigger than that and there are too many stars in view which makes it incredibly confusing. The 7 X 30mm (home made from an old but good bino) has a wide 7-8 degree field and shows stars down to mag 8 in my fairly light-polluted skies. I just cant imagine life with any other setup. I couldn't get the hang of the telrad-going from what is basically a naked eye field-of-view to 0.7 degrees of my lowest power was quite unworkable. even if it was 50% wider, I don't think I could do it.

(Don't suppose anyone will agree with me but never mind - am used to being a maverick !)

Alan.

[Merlin999]

With an 8x50 finder it can be very hard work - in the end I bought a GoTo upgrade and had done with it

After our recent disaster I have to admit I was wondering whether I should have gone for GOTO!!

Gosh so many different viewpoints. :icon_confused:Thanks Ronin. It sounds like an RDF could solve the problem.

Thanks perrin6, interesting you gave up on the Telrad and just use your Finderscope.

Yikes. No idea what is best option at the moment so I think I'll go and sleep on it!

[Johnboy]

I've found that with a reticule finder like an RDF, Telrad or Rigel is that you use them with both eyes open. It's hard to explain but it basically means that while one eye is looking at the whole of the sky, the other is looking though the viewfinder. The combined view I find is unmistakable. If you or hubby are looking at say, Vega, you will see it with one eye on the sky and the other through the finder, which of course has the red dot or circles allowing you to line up the star.

[LukeSkywatcher]

No one can be rubbish at star hoping. All it takes is for you you to know a single star or constellation and you can and will find your way around the bight sky.

[Moonshane]

I use a Telrad, a Rigel, a 6x30 AND a 9x50mm optical finder - not on the same scope of course!

on my bigger dob I use the Telrad and the 9x50 and on my 6" dob I use the Rigel and the 6x30.

The mean reason for the differences are that the 6" dob is a pig to balance (although better since I fitted a friction brake) and the less weight at the top end the better.

Can say that I have occasionally been lazy and not put on the optical finders and don't really miss them half as much as when I don't put the Telrad/Rigel on.

With the Telrad/Rigel I can put say Jupiter or a star in the right place and it's in the eyepiece, even when at quite high magnification (eg 150x with my 11mm Plossl).

My MO though is normally, Telrad for initial placement. this product which I prefer over the two and like any finder, if aligned properly, will LITERALLY transform your ability to put the scope in the right place.

I then take a look in the optical finder and then the eyepiece.

It's rare that unless something is very faint that it's not then obvious in a wider field eyepiece. You can then move the power up to the 'right' level for the target.

I think that any optical finder is good but the RACI ones are seriously much easier to use as they are 1) the right way up 2) less 'craning' on your neck. They are not called right angled corrected image finders for nothing