Getting the most out of our Dob

[JPete]

Hi there, we (me and my 12yo son) have a 10in Dobsonian. We get it out a bit, but its heavy and awkward so maybe not as often as we should. Once we have it out we can see cool stuff like Jupiter and it's moons but we would really like to be able to see it a bit clearer, see more of the colour and lines in its atmosphere.

1. Has anyone mounted some permanent so you can just take the OTA outside and plonk it on the mount. The normal dob stand isnt that awesome on uneven grass.

2. What is a good set of eye pieces for this sized scope? I have a 9 20 and 25.

3. What else would help us make the most of this scope? Maybe a barlow? A solar filter? anything else?

Appreciate any thoughts!

[omegacrux]

Hi JPete
one big hint .
Do not let the base get wet , eg wet grass
it will stuff it , the one I had I always kept it off the ground they soak water and expand !

David

[Renato1]

Your dob will take a while to settle down temperature wise.

It may well be that Jupiter isn't clear some nights - especially given its angle in the sky will be over a lot of houses putting heat out. But some nights it should be clear and sharp. If it never is, it probably needs to be collimated.

If you are somewhere dark and you find a deep sky object, take advantage of atlas mopping - that is, start finding all the objects on the star atlas map around the object you just found (though you may need a UHC filter for planetary nebulas).

if you have a straight through finderscope, remember to keep both eyes opened when trying to locate a target star. Many find this much simpler than trying to aim with one eye like with a rifle.

If you have a right angled correct image finderscope, consider getting a 1X red dot finder for your telescope, it makes it much easier to point your main finderscopes at targets.

Regards,
Renato

[michaellxv]

Would it help moving it about if you put it on some wheels? If you are taking it out onto un-even grass you will need larger wheels than if you use it on a paving/concrete. This will also lift the base off the grass to avoid it getting damp.

[xelasnave]

Make it easy to use, wheels and a place to park it, say a small slab.
The main thing is getting as much time at the eye piece as possible with the gear you already have.
We all feel the need to improve our gear when really we don't use it effectively.
An eye patch is a good idea to protect night vision.
Good luck don't rush to buy stuff.

[Regulus]

- Firstly, you might make a sturdy, low table to put it on to keep it of the ground and give you a flat base for it. It is also useful for holding you ep's/barlow and coffee etc. And you can prepare a sq metre of lawn for it as a level place to sit the table and scope in case you eventually use a steer-to guider (Argo Navis for eg), or an Android phone using something like Stellarium or Skyeye to help you find targets to look at. By having a level setting the accuracy will be better when using the device mentioned to find your targets.
- Secondly, a good wide ep is useful. A 32mm and 40mm are great for wide nebulas and just general 'sky-surfing'. [$49ea at Andrews for the 2" SPlossls - http://www.andrewscom.com.au/site-section-10.htm]
Add to that a high magnification ep for lunar close-up and planetary use. Perhaps a 5mm which would give you about 250X, which is well within the reach of you scope.
Add a 15mm (2" Bintel Superview $49) to fill the gap between the 20 and the 9mm will find uses too.
So: Adding a 5, a 15, and a 32 and/or 40 EP would round out your eye pieces nicely.
A strong moon filter, because looking at the moon without it will leave you with a 'black spot' in you vision for a good 15-30minutes afterwards, and make it difficult to see fainter objects until your vision recovers. These are just $19 at Andrews
Also try leaving the lid on the scope and just removing the 50mm cap part when looking at the moon (using the luna filter) and you will find that it is less stressful to you eyes and increases the contrast considerable. This is also good if you try to 'split' double stars like Alpha Centauri.
This 50mm aperture in the lid is also a quick cheap way to get a solar filter for visual sun observation. By making up a cover to fit snuggly (and by that I mean safely/firmly) over the 50mm aperture, using the solar safety film sheets that are available cheaply. Or just buy a good quality glass one to fit the smaller aperture. You don't need 250mm aperture to get good views of sun spots etc.. [don't forget to NOT look through the finderscope when pointing at the sun. I now that seems obvious, but a momentary lapse of attention..... not worth thinking about. [If you have doubts then take the finder off when viewing the sun so accidents don't happen :-) ]
A few ideas I hope are useful

Trevor

[JPete]

Thanks for all of the info. I will make sure i dont get it wet, i didnt think of that.

To be honest we haven't been using a guide other than the planets app on iphone, we mostly look at the moon and planets. Maybe we will make it out mission to tick off all of the messier objects?

Jupiter this week for example is sharp, although i could see the heat haze after some time, i have a fan on the scope but havent connected power, i will sort that out next. Its more that its not 'zoomed in enough'.

I think we will put it on wheels and pour/pave a small slab and path. I think I will put a flat base for a pier in for a future scope.

I am going to start looking for a barlow and a couple of eye pieces...i like the DIY idea for solar...but wont heating the mirror be a big issue?

[rustigsmed]

hi jpete,

another thing to do is to check collimation when you are moving it around so much. when I setup it generally needs a small tweak every time. if it is out the image quality is obviously going to be inferior. so things like bob's knobs http://www.bobsknobs.com/Newt/Newt.html to replace the screws on the secondary mirror are a good investment to speed up the process - and of course a collimator if you haven't already.

at the moment Jupiter is fairly low so the best time to view is actually around 2am when it is at it's 'highest'. but it is gradually coming earlier and earlier in the evening (about 4-5 minutes each day).

keeping uptodate with astro 'events' is good, http://astroblogger.blogspot.com.au/ too.

You could also join the Mornington Peninsula Astronomical Society http://www.mpas.asn.au/ for further inspiration and hands on advice (the Briars).

as for the mirror and solar, it is not in direct sunlight because you block it with the filter before it enters the tube...

cheers,

rusty

[JPete]

Thanks for the tips. We have been using it a bit over summer. Father Christmas delivered some new EPs and a barlow and a lunar filter.

We have noticed the planets are a little blurry - we have never collimated this scope - is this likely to be an issue?

We find the focuser is not very accurate or easy to use...are focuser upgrades worth considering? If so, is the $80 one at Andrews ok or would something else be more ideal?

We still struggle with the getting it outside part...has someone invented something for carrying these monster around yet?

Whats a good set up for viewing venus and mars which are high in the sky right now? We are struggling to get big clear views of them

We have never been able to find a galaxy with this scope - is it possible, which one and with what settings?

Appreciate any tips! :)
Cheers

[iborg]

Hi

Something else to look at are the nebulas in Orion.

Find the three bright stars of the belt, then move right a bit, then up a bit.

Start with an eyepiece with a wide FOV (field of view, ie big number).

You probably won't see colour, but should see the grey nebula outline and some bright stars.

When it is a better position, look closely at the stars in the Southern Cross.
Several are double stars.

Enjoy

Philip

[grimsay]

Hi JPete,

Have you considered getting a trolley to move your Dob? See this article (http://www.iceinspace.com.au/63-12-0-0-1-0.html) on tips for moving your Dob using a basic transport trolley (I picked one up for my 8" from Bunnings). That should make things a bit easier.

Thanks,
Iain

[Stonius]

Yes, collimation is a must. Every time. Even a few mm can make all the difference. Think about it, even if you're 4mm off center, they's waaay of in terms of the width of your eyepiece. It's scary at first, but once you get your head around it, it's no problem, and well worth the trouble. I often recheck mine halfway through the night.

Markus

[Allan_L]

Planets are often a little blurry, because generally you need high magnification to see any detail and if the atmosphere is not optimal, then the image will appear blurry.

A test for this is whether a lesser magnification is crisp?

Venus is often blurry because the entire atmosphere is cloud covered and it brightly reflect the sunlight.

Mars is often blurry because it is so darn small and hard to get any detail at the best of times.

Test your eyepieces on the moon (when less the quarter full).
Are the images sharp. Does increasing magnification keep relatively sharp images.

Another factor could be if the mirror is not at ambient temperature.
Not such a huge issue with a dob due to their open nature, but still a possible factor.

Are you viewing over concrete paths, or houses, etc that may have retained heat and emit a rising haze after dark. (like heat rising from a hot road makes shimmery patterns).

And primary and secondary mirror alignment (collimation) is also something to be considered in your setup.

[fbk]

Hi JPete.. I have a 12" which I got only recently as well. To touch on the above points:

Proper collimation is essential. Being a little bit out is not really noticeable but if you've never done it yours could be miles out which would really affect your viewing. It can be daunting initially but once you've done it a few times it only takes a minute. I do mine every time too.

Planet wise, Mars and Venus are always kind of disappointing. They are tiny, I've never seen Mars as much more than a small pale orange disc. Venus you can see the phases like a little half moon at present which is a nice target early in the evening. It's very bright like the moon so use your moon filter too. You can also leave the front cover on the scope and just remove the 50mm cap. Position the hole so that it's between the spider vanes. For most things this will slightly reduce the resolution/detail you see but there is none there on Venus to lose. Try it on the moon as well.

Saturn is the most impressive planet to look at in my opinion but rises just before the sun so give it a few months before it's higher in the sky late at night. It too is pretty small so don't expect it to fill your eyepiece. It will take a bit of magnification, even your 9mm + barlow will probably not give you the "zoomed in" view you are hoping for. When you use more magnification you lose detail as well as magnify everything else like atmospheric disturbances, or even the air currents if your mirror is not at ambient temperature. Sometimes you just have to dial it back. And sometimes when objects are low on the horizon it's just not worth bothering trying to see much detail on them.

One thing you will learn if you haven't already is that visual astronomy is not for the instant gratification seeker. It takes patience... for objects to be in the right bit of sky at the right time of night, in the right conditions, even when conditions are perfect you generally don't always peek in the eyepiece and go "wow". Sometimes you wonder why you even bother. But just like how you see many more stars after being outside for while, you also start to see more detail in what you're looking at. Get comfy, keep all light sources away, spend some time looking at the same thing, you will start to make out more and more. You can see banding on the surfaces of Jupiter and Saturn and also the Red spot if it's visible. Look for Saturn's moons and the Cassini division in the rings. None of these jump out at you, especially when it's smaller than you're expecting, but you will see them eventually and more, and that's part of the appeal.

The best thing you can do with your 10" is wait for a night with no moon and take it as far away from light pollution as you can. I go for a drive about 100km from the city and usually stay out well into the wee hours to make the most of it. Once your eyes adjust you'll see things you just won't get to see from your back yard unless you live well out of the city. Deep space objects like galaxies, nebulae and star clusters.. same advice as for planets. Initially they might look like fuzzy blobs but the longer you look the more detail you see. Then you get hooked on looking for the next one!

I did some mods for mine here (http://www.iceinspace.com.au/forum/showthread.php?t=152000) that include a guidance/location system of degree circle on the base and digital gauge for altitude, for around $50. It makes it simple to find things using a free star app like Sky Safari which gives you live coordinates of every object. Also built a base which keeps the scope off the ground and makes it level. Of course you don't need any of these if you just plan to plonk your scope down now and then for a look around but for me finding the deep stuff is more appealing than seeing Jupiter and Saturn, impressive as they can be. And many of them will fill your eyepiece instead of looking like a pea sized ball.

Have fun :)

[JPete]

Thanks everyone for the eyepiece tips. We have taken note.

Can i use a simple/cheap collimation tool like http://www.ebay.com.au/itm/Telescope-Collimation-Eyepiece-Scopes-1-25-for-Newtonians-Full-metal-AU-/112088783721?hash=item1a19031b69:g: wFEAAOSwEeFU~6O~ or is this really a case of buying the proper tools and getting a proper result?

Our base has some mods, so we can adjust the left and right with fine movement. But no others yet. My end cap is one solid piece, we dont have a 50mm insert.

http://i67.tinypic.com/2a8q911.jpg

Current viewing spot is on a timber deck...not concrete. I think the nights have been warm, but not so much the ground.

I am not keen on the trolley and foams ideas. I want even more simplicity. We have an idea with wheel barrow handles and wheel we can lift under the handles on the mount - pics to follow if this experiment works :)

We havent tackled any deep sky, but my son is mad keen to see a galaxy, so thats this weekends mission. Galaxies and nebulas We will take our time and try and a few things.

We understand light pollution isnt optimal, but travelling with the scope isnt realistic for now.

thanks for the tips...i'll be back with more questions :)

[Allan_L]

The galaxy Centaurus A was my first Galaxy, I found star-hopping with my 10" DOB.

I start at Hadar (Beta Centaurus - the "pointer" closest to the Southern Cross)) and star hop to Epsilon Centaurus, then its equal distance straight line hops to the Bright Cluster (Omega Centauri) and then to Cent. A. See the chart attached that Wade posted a while back taken off Starry Night.

I used a red dot finder to position the scope where I thought it should be roughly. Then was able to spot it though my 9x50 finder scope. And with a low magnification eyepiece (27mm), there it was.

And this was from my own backyard.

Problems are:
1. It doesn't come up till about 11pm at the moment.
2. You have no chance with the current bright nearly full moon.

But one to save for better conditions.

When you find it, it should look a bit like this (photo posted by graham.hobart in May 2011) Thread HERE (http://www.iceinspace.com.au/forum/showthread.php?t=75809)

[NoTan2]

JPete,
I also have only a timber deck on which to position the scope. I was a bit concerned that it might be a bit shaky but it's built strong and seems to be satisfactory.
I bought a hand trolley with the biggest tray I could find but even then it didn't reach halfway under the base. So I bought some plywood and cut it the biggest size that would fit between the legs on the dob's base (with a slot for the centre bolt) and bolted it to the trolley. That makes it long enough to reach all the way under the base. Three pillows (permanently strapped to the trolley uprights) and a couple of octopus straps (which probably aren't even necessary with the large and more secure tray) and it's outside. Takes two minutes.
But I have seen a photo somewhere online with wheelbarrow handles as you describe. Be interested in your results.

[NoTan2]

Allan,
Thanks for that explanation. I'm just about ready to start doing more than meandering aimlessly around the sky. I was going to start by trying to find M41 but I'll follow your instructions instead - at least when the moon goes away. (I went outside at 10pm last night, had a chuckle and came back inside.)