Newbie Help with dob 10 inch

[Shrekies]

Hello all 

i am a complete newbie. A couple of months ago I bought an old Russian Tal 1 for £33. On my first outing I had a great view of Saturn (for someone who has never seen Saturn’s rings before) the best £33 I’ve spent in a long time. This experience made me want more, so I have just bought a 10 inch flextube dob (maybe I should have gone for an eq). I don’t know if it’s the lack of knowledge of the skies or inability to operate this monster but I just can’t seem to find anything . I’ve been using the sky night app on my iPhone but can’t seem to locate . I really want to see some cool stuff now I’ve seen Saturn(and would love to see more of it ). Any help or advice would be appreciated, also any clubs that meet at weekends in Leicester (work nights during the week) where I could get help, advice and knowledge.

thanks in anticipation 

simon

 

[John]

Hi Simon and welcome to SGL.

You have bought a fine scope in the 10" Flextube. I'm sure you will get lots of advice on how to get the best from it. Mine is to make sure that the finder scope is accurately aligned with the main scope view and to get a good guide to the sky in hardback format - something like "Turn Left at Orion" or similar.

There is so much up there that your scope can show you but you need a step by step guide to getting to these sights.

My other "tip" is to use the lowest power eyepiece to start with - thats the one with the highest focal length in mm - probably 25mm. This will show a bit more of the sky which makes finding things easier.

 

[Stu]

Welcome to the forum. Firstly I think assuming you are wanting to do visual astronomy then the dob is a better choice than an EQ mount.

What sort of Finder do you have fitted? Adding a TelRad Finder can really work well as it projects 4, 2 and 0.5 degree circles against the star background and allows you to star hop or position the scope very easily. In conjunction with a 9x50 RACI Finder you should be able to locate objects easily and centre them in the scope eyepiece quite successfully.

Making sure that these finders are aligned is also a very important task and one which is probably easiest done during the day.

Working out the scale of what you are seeing through the Finder and the scope is also key to understanding what you are seeing and relating it to the starmap you are using.

[Shrekies]

Thanks for the reply. I think I have the 9x50 finder. I set it up during daylight but at night there seem to be too many bright  stars in view(the difference between a 110 & a 250). Not sure if I jumped too big too soon. I’ve read that telrad finders are great but I don’t have the funds at the moment. Some hard literature would be good but wouldn’t know what to buy. 

I will still be trying to find a good visual regardless of how long it takes. That first view of Saturn has got me hooked. 

[Dave In Vermont]

There is a thread here that will help you know more about what to expect - and it won't cost you money to read it:

 

This should help you out before your chosen book is ordered and arrives. 'Turn Left At Orion' would be an excellent choice, by the way. As would, perhaps, downloading Stellarium - which is FREE - to help you understand what all is 'up there.' A 10" Dobsonian Newtonian is a very powerful instrument, and is most capable of being a "Lifetime-Telescope" - is to say it's quite able to show you new and interesting objects every night for the rest of your life. Even if you got it the day you were born!

Your journey has begun & Welcome to SGL - it's nice to have you aboard!

Dave

[Stu]

Not used the app you refer to, have a look at Stellarium on PC or smartphone, or my favourite is SkySafari which is a paid for app but very good, just the basic version would be fine. With this you can fine tune the stars visible to match what you see in the scope which really helps.

Dont forget that the view in your Dob will be upside down, through right angled Finder it will be left/right reversed, through a straight through Finder it should also be upside down (I think) so it is worth understanding these things so you can relate to the different views.

Use your longest focal length eyepiece to start with which will give the widest field of view to make life easier.

[MarsG76]

Baby steps, target the brightest objects first. You already dipped you toe in the water with Saturn, Your next planet that will impress will be Jupiter in a few months time and of course lets not forget the moon... take a look at it when it's first quarter... great view. Mid Next year, get ready for Mars... one of the closest approaches for a long time.

When it comes to deep space objects, again start with the brightest objects and work your way to the dimmer, smaller and harder ones to see.

An excellent object reaching world wide skies these nights is THE ORION NEBULA.. again a excellent object to stat with.

For the best views of-course you want to be in as dark of a location as possible.... keep away from white light and only use dim reed light to preserve you dark adapted sight, which is needed to see the faint nebulae... the more dark adaption you have the more nebulosity you will see.

Protect that dark adaption like its a precious gem..... even you mobile phone set at it dimmest/night time setting is TOO BRIGHT... if you want to use your phone for starmaps, get some red sillaphone and overlay it on your phone at it dimmest setting... it'll be hard to see until you're dark adapted which takes about 15-20 minutes

 

Good luck

[ronin]

An app is fine for getting an idea of what is up there and where it more or less is, but they do not make the object appear in the field of view. Just been out with binoculars and what Skysaferi shows and what the binoculars show and what my eyes alone see is 3 utterly different experiences. Apps are not the answer to everything, although Android and others would have people believe otherwise.

Learn the constellations and learn what is in each and where the major objects are, that gives an idea of where you need to start looking.

10" scope is nice and big but that alone creates troubles, You are likely to be getting too many stars in view (initially) to be able to deterime what you are looking at, the field of view is relatively narrow. M42 is "big" but getting it in view is not easy.

Once read that a Dobsonian is a "specialist" scope, and I tend to agree. You have to spend time learning how to use it, and that time is not generally going to be a one day or two day period. Try 2 months. Yes you get a big mirror, but that is about it. You aim it, you acquire targets, you follow the targets. You have the scope now the truth is you need to learn how to use it and that comes with practise. With the arrival of the Skywatcher Wifi it will be a case that 6 year olds will be aiming scopes via their mobiles and that will become the norm.

Classic answer is get a wide field eyepiece, a 30mm Plossl, or a 25mm BST Starguider. Actually the plossl may be a bad idea, a 10" scope is likely to need better then a standard plossl and I suspect that a 32mm TV plossl is out of budget.

Clubs: http://www.astronomyclubs.co.uk/

[Piero]

That's a great telescope which can show you targets for a lifetime if used properly.

You need to make sure that the finder is aligned with the telescope. The view in your finder and telescope is rotated by 180 degrees. Also, Newton telescopes need to be collimated. This simple tool doesn't cost a lot. It is the primary mirror that requires collimation most of the time. Nothing to be worried about. After some initial practice, it is a straightforward process.

[Dave Lloyd]

Hi Simon, welcome.

[Stu]

19 hours ago, ronin said:

Just been out with binoculars and what Skysaferi shows and what the binoculars show and what my eyes alone see is 3 utterly different experiences.

@ronin if you learn to use the apps properly then you will be able to match what you see on Skysafari with any particular view be it naked eye, binoculars or scope. Just set the field of view correctly, the orientation and the limiting magnitude of stars and DSOs correctly and it is very simple to find you way around.

[Jimtheslim]

I have a 10" dob and was having the same problem. I'd try and line things up according to nearby stars and put the crosshairs of the finder where I thought it should be and was immediately lost due to the back to front and upside down magnified image in the finder. I bought a telrad and use it in conjunction with some telrad finder maps (available to print for free off the internet). These two acquisitions have completely unlocked my viewing experience and the best investments I've made for my scope. In fact I've taken the finderscope off and haven't used it since.

[cletrac1922]

21 hours ago, Shrekies said:

Hello all 

i am a complete newbie. A couple of months ago I bought an old Russian Tal 1 for £33. On my first outing I had a great view of Saturn (for someone who has never seen Saturn’s rings before) the best £33 I’ve spent in a long time. This experience made me want more, so I have just bought a 10 inch flextube dob (maybe I should have gone for an eq). I don’t know if it’s the lack of knowledge of the skies or inability to operate this monster but I just can’t seem to find anything . I’ve been using the sky night app on my iPhone but can’t seem to locate . I really want to see some cool stuff now I’ve seen Saturn(and would love to see more of it ). Any help or advice would be appreciated, also any clubs that meet at weekends in Leicester (work nights during the week) where I could get help, advice and knowledge.

thanks in anticipation 

simon

 

21 hours ago, Shrekies said:

 

Hi guys from land down under

Also have a 10 inch flextube, and use for school and scout/guide groups

Couple of secrets to success

First thing, get yourself a right angle spotting scope, makes life so much easier, than having to knee on the ground trying to look through the spotting scope

Set the spotting scope cross hairs while still day light

Pick a distant object, and align spotting scope to image through the dob

I also use a laser pointer, and lay along side of mount for spotting scope, and adjust the dob to where I want to view, and do final alignment using the spotting scope

Use smaller magnification eyepiece as well

20mm as opposed to 10mm which comes with the scope

I also use a 17mm wide angle eyepiece as well, and if easier for 5-7 yo's to view through doing school and scout/guide movement  program with club belong to

If still no joy, rock along to your local club, and have the members there check the culmination for u

 

Cheers

 

John

[Chefgage]

I struggled a bit to start with trying to find objects using the 9x50 finder.  Then i got a rigel quick finder which is basically just a viewing window with no magnification but has a couple of lit up circles that it superimposes on the viewed sky.  This quickfinder is aligned to the scope as well so you have the quickfinder, 9x50 finder and telescope all lined up. Then you can center a star for example in the quickfinder as that view is just the view you see with the naked eye. Then you can dial in the star into the center of view using the 9x50 finder and then finally with the scope.

All this made locating objects/star hopping alot easier.

[Nyctimene]

Welcome to the forum from a German dobsonaut!

7 hours ago, Chefgage said:

so you have the quickfinder, 9x50 finder and telescope all lined up. Then you can center a star for example in the quickfinder as that view is just the view you see with the naked eye. Then you can dial in the star into the center of view using the 9x50 finder and then finally with the scope.

Another vote for the combination of Telrad (Rigel/Red Dot Finder)+9x50 RACI (=Right Angle - Correct Image) finder + a 2" widefield eyepiece; in your case, with a focal length of 28 - 30 mm. I'm using this with my 18" Obsession, and it works really well.

Take yourself time, stay with the brighter and easy to find objects (moon, Orion nebula, Double cluster, the Auriga clusters  M 36, 37, 38 etc.), until you feel more familiar with them. It's helpful to scan the object's location first with bins.

You bought a really good scope, a "lifetime instrument", as Dave said above. Within a few months, you'll have tamed your little "monster" (incl. collimation), and will be delighted to explore the winter sky. Keep asking here, and reporting!

Clear Skies

Stephan

[Scooot]

A cheap aid to finding things is a Wixey angle gauge. It will help you get the correct altitude which you can look up in your Iphone app. https://www.machine-dro.co.uk/wixey-digital-angle-gauge-with-magnetic-base.html

A more accurate & complete aid is to fit two encoders and use Astro Devices Nexus http://www.astrodevices.com/Products/Nexus/Nexus.html

 

 

[alanjgreen]

Hi Simon,

1. first thing is to change the finder. Either buy a right angled correct image RACI finder if you like the experience of using a 8x spotting style scope (RACI will remove all that back to front view nonsense). Or switch to a telrad of similar device as these only show what you can see rather than showing 8x meaning you see too many stars in the finding process and get confused. The telrad will also provide navigation circles in the view to help further navigation...

https://www.firstlightoptics.com/finders/telrad-finder-astronomy.html

https://www.firstlightoptics.com/finders/skywatcher-9x50-right-angled-erecting-finderscope.html

 

2. Buy a nice low power WIDE field eyepiece (82 or 100 degrees field of view (FOV)), this will enable you to see more sky in the eyepiece and increase the chance that you can see whatever you lined up on with the finder! It will also mean less nudging of the dob is required as the object will stay in your view for more time (once you have found it). I would recommend a nice wide 20-30 mm eyepiece to get you started, you can always apply more magnification later (by switching o an eyepiece will less mm once you have the object nicely centered in your wide field eyepiece) but a good low power eyepiece will bridge the gap between the dob and the finder.

https://www.firstlightoptics.com/explore-scientific-eyepieces/explore-scientific-82-degree-series-eyepieces.html

expensive = yes (but will last a lifetime. Pick them up 2nd hand if you keep an eye on astrobuysell or this site for 70% of new price)

Alan

[Chefgage]

51 minutes ago, Scooot said:

A cheap aid to finding things is a Wixey angle gauge. It will help you get the correct altitude which you can look up in your Iphone app. https://www.machine-dro.co.uk/wixey-digital-angle-gauge-with-magnetic-base.html

A more accurate & complete aid is to fit two encoders and use Astro Devices Nexus http://www.astrodevices.com/Products/Nexus/Nexus.html

 

 

Thats what i ended up doing, i use the two encoders when light pollution stops me seeing stars within a constillation.

There is a write up here

https://stargazerslounge.com/topic/296417-modifications-to-my-200p-dobsonian/

[Scooot]

6 minutes ago, Chefgage said:

Thats what i ended up doing, i use the two encoders when light pollution stops me seeing stars within a constillation.

There is a write up here

https://stargazerslounge.com/topic/296417-modifications-to-my-200p-dobsonian/

That looks very good. I used a wixey before I setup the Nexus Push-To system which I now use on both my 10” & 16”. My wixey solution wasn’t as sophisticated as yours, I only used it on the altitude which was a great help over nothing.

However the Nexus is much more accurate than the wixey. The scope doesn’t need to be level and I track the movement of the scope on the sky safari screen on my IPad. No problems seeing it in the dark using the iPads colour filter to create a night vision mode on all apps. 

[brantuk]

Hi Simon and welcome to SGL

Nice scope - I used to have the 12" flextube till I upgraded and it was great. If you need any local help feel free to send me a pm and we can maybe arrange a phone call or meet up one night. I can give you all the info you need about local clubs and observing sessions. All the best!

[Astro Imp]

As has been mentioned you've got yourself a fine scope, you'll never be short of objects to view.

I see a Telrad has been mentioned several times and I agree a great piece of kit BUT when I got my 8" flextube there was insufficient room to fit it so I went for the Rigel Quickfinder. As you have the 10" against my 8" you may find there is room for the Telrad, would be worth checking with someone who has the 10".

Good luck and enjoy.

[JOC]

I went from giving up on finding stuff after 20 minutes to being able to land on any star I could see in about 30 seconds flat once I bought a dual finder shoe (there is a guy in Poland 3D printing them for around a tenner on the famous auction site), and an el cheapo SW red dot finder (I also got a RACI optical finder, but I think I'd be OK with a straight through one now).  Even though my RDF is not spot on it is close enough, and I just tune the RACI in until it is spot on with the EP.  If I land on something with the RDF it is then somewhere in the RACI and once it is centre in the RACI I can see it in most EP's.  Problem solved for me.

[Shrekies]

Hi all

Thanks for all your tips and suggestions. 

It looks like I’ll be ordering a telrad at the end of the month. The angle gauge sounds like a good idea if I combine with a compass, then I’ve got 2 directions. 

I’m sure at some point I’ll get the hang of it. A little problem like this won’t be putting me off.