Dobsonian to something else?

[mbyrr]

Hi folks

I've had a Bintel 8" Dobsonian for about a year now, but unfortunately I am not getting much use out of it. The problem is it is too big and hefty for me, and where I live there is too much light pollution. Consequently, I'm considering selling it and getting perhaps a refractor or reflector scope instead. I'm looking for something that is easy to store, perhaps folds up, on a tripod, and is easy to transport and set up.

So here are my questions:

1. What is a comparable or decent alternative, of around the same cost as the 8" dob (~$500) ?
2. Would I still require the collimator? (Wondering if I should sell it also with the dob).

I've been looking at the Bintel site and saw a couple that caught my eye but don't know if they're good or not, so any opinions, recommendations, thoughts are appreciated, thanks!

http://www.bintel.com.au/Telescopes/Refractor/Meade-StarNavigator-102/1290/productview.aspx

http://www.bintel.com.au/Telescopes/Reflector/Skywatcher-SW500S/580/productview.aspx

Thanks heaps!

cheers
A

[barx1963]

Hi Anthony
Sorry to hear that the dob is not being used. The 2 scopes you have highlighted as with all svopes have pros and cons.

Firstly the refractor. About the only pros I can think of are 1. you will not need the collimator 2 it has go to 3 it may be slightly more portable than your dob. The big con is that it is a serious step down in aperture. It is only 4" so you are reducing your available light by nearly 4x. You mention light pollution, a small scope will only exerbate that problem.

Next the 6" newt. This is essentially the same scope as your dob (they are both newts) just 6" instead of 8" and on an EQ mount. The cons are 1, It is probably as heavy as your dob if you are using the EQ3 mount. 2. You will have to learn to polar align. 3. Newts on EQ mounts give you some "interesting" eyepiece positions. If you enjoy kneeling on the ground trying to look vertically up into an eyepiece, this is the scope for you!!:P 4. You will still have to collimate. Pros 1 you will learn abit about using an EQ mount if you decide to get into imaging 2. If can be retrofitted for go to.

Quality wise both scopes would be OK, its suitabilty that is the concern. I would urge you to perservere with the dob, there is a reason they are IMHO the perfect beginners scope!!

Hope this helps

Malcolm

[moonunit]

Got me flummoxed why ppl bother with small scopes, go straight to a 12" or 16" Dob and put the past behind you.

[naskies]

Binoculars? Small + low power and you can just walk outside and look up, or slightly larger and you can put them a photographic tripod for easy pack up and transport.

[Chris85]

He said that even an 8" was to much to handle? Why would he go bigger?

[Larryp]

I have a 90mm triplet apo and live in an area with lots of light pollution, but the amount of deep sky objects visible in it is quite remarkable. The difference is the superior contrast you get with a good refractor over any other design of scope.
I went with a small refractor because I cannot lift heavy stuff these days, and it is quite portable.

[Forgey]

Comments like this do not help. Did you not read Antony's post - he said "The problem is it is too big and hefty for me"

Antony, I have not used one of these but this scope looks like it might suit you.
Skywatcher GOTO 5-inch Reflector Telescope
http://www.ozscopes.com.au/skywatcher-goto-5inch-reflector.html
It has the Alt-Azimuth mount like the dob so it's easy to setup and also has auto tracking and goto.

[Steffen]

I have to agree with Malcolm. Try to make the 8" Dob work, going smaller is likely to leave you wanting. Many of the handling issues can be overcome with DIY means, such as adding wheels or simply adapting a hand trolly. Unless there are firm show stoppers – such as, can't fit the scope into the car – I'd give that a go. Of all types of scopes the solid-tube Dobsonian is by far the easiest and fastest to set up. Provided you can carry it :D

Laurie, you should mention how much a good small refractor (plus mount plus tripod) is that's good enough to make you forget the lack of aperture ;)

Good, portable, affordable – pick any two :shrug:

Cheers
Steffen.

[barx1963]

Handling dobs is often most easily solved with a bit of thought. I made a set of straps for my 12". Just some plain webbing with velcro and sewed on some more to make handles. Worked a treat . That and a modified hand trolley for the base and I could carry and set in 2 mins.

Malcolm

[ZeroID]

Antony states he is looking for something " and is easy to transport and set up. " hence he is looking maybe to escape the LP now and then. In that case a good 4" refractor is good option. Even a smaller newt works better in darker skies. I took my 80mm to a seriously dark site once and it almost scared me there was so much visible.
Clarification Antony please .... if we understand your plans you may get better advice. Personally I'd have both ( Ooops, already do ... :rolleyes:) just to cover all my options. You never know when the beast will awaken and summon you to look up again.

[RobF]

What's your situation at home Antony? Do you have poor horizons or access to backyard exacerbated by lugging the dob? Many hear have come up with interest solutions to improve portability.

An 8" dob really is a very versatile scope. There may be ways of taming your existing scope. The best scope is the scope you feel like setting up though, so good you're being realistic here.

[janoskiss]

Hi Antony,

I have owned / do own: 4" Newtonian, 8" f/6 GSO Dob, 80mm ED refractor, 4" SW Mak, 12" GSO Dob, 10" SW Dob, 8" f/4 custom made Dob (GSO optics), 6" Intes Mak. I was living very close to where you are when I got started, so I can empathise with your light pollution woes. I spent many nights in the back yard and occasionally in local parks with my 8" GSO Dob in Mt Waverley, as well as out in the country under clear and dark skies. By far the most satisfying and easiest to use scope was the 8" GSO. Unfortunately one carefree / careless night, having a bit of a party at a friend's place, we left the scope in the driveway and someone came along and took it. I still miss that scope. It was the best all rounder.

If you ever decide to sell yours, please do let me know!!

So my advice to you is to try and make your 8" dob work for you. Simple mods can make a big difference. Some things I did to mine: attached handles to the base which made i much easier to move around, made the alt-az bearings smoother (like ebony star on the base), got her a better finder, learnt how to keep it collimated precisely, got some nice EPs, binoviewer... And every clear-night dinner party she'd be there to knock the guests socks off. I did and do the same things with all my other scopes. But the 8" f/6 really hit the sweet spot for performance, ergonomics and mobility.

You might like to upgrade to one of the newer collapsable models. Maybe even a goto model. But that would be well over your budget, so really I think you have the best scope your money can buy.

[mbyrr]

Hi everyone, thanks for your comments, I appreciate it.

To give a bit more background to my situation, I live in a unit with a small courtyard out the back, half covered by a large tree, so no real backyard to speak of. I have a long driveway in the front that I have used for stargazing, but there is alot of light pollution out there due to lights outside the units.

I'm sure that there are ways of making the dob more portable and less cumbersome, but knowing myself (how un-diy-inclined I am, plus on the lazy side), I'm not convinced I'd get around to making it work for me, unfortunately. It is also quite large for car transportation, at least for mine anyway.

I am still keen on the hobby tho, but really only if it's on the easier side.
Considering how little I have seen with the dob, going smaller/lighter/more portable is not a huge deal to me, as long as I can still see something (preferably Saturn's rings, one of the reasons I got the scope in the first place).

Oh and I dislike collimation immensely (I have never got the hang of it). :help:

[barx1963]

Anthony
This is one of those cases of what type of LP do you have. Urban areas tend to have generic LP which is simply the city glow brightening the sky and then there is local LP which is neighbours lights, streetlamps etc.
The first type in my experience is best cured with aperture. Yes refractors have better contrast which can help, but the fact remains you collect 4 times as much light with 8" against 4"
Unfortunately there is no simple cure for type 2 LP. I have resorted to erecting shadecloth screens on my fence to block the neighbours lights.
If your courtyard is the best area to observe but has limited views of the sky still give it a try. My backyard has huge areas I cannot see due to trees so I just pick a constellation I can see and explore it in detail.

Collimation is not really difficult, on a small scope with a little practice you should be able to do the job in 2mins each night when you set up. Are you just using the laser or do you have any other tools? Here is an excellent guide to collimating a small Newt using a cheshire. http://www.astro-baby.com/collimation/astro%20babys%20collimation%20guide .htm
I found with my 12" I would go through this procedure every 2 months or so (or whenever I had take the scope apart for cleaning or mods!) and just tweak it with the laser each night.

Not many people enjoy collimation BTW (although there some who do!!!:shrug:
The trick is to have a routine and try to understand what you are trying to achieve. When I was learning I set goals, trying to get the scope collimated within a set time is an easy way. Start with 10 mins and work down to 2 mins.


Malcolm

[janoskiss]

I hear ya. But I still feel I have to say this: Collimation is like tying your shoelaces. If you never learnt how to do it, it's really hard. But once you got it, there is nothing to it.

Sounds like a refractor or a Mak might suit you better. For what you want, you will have to spend considerably more than $500 though to get anything half decent. And if you are really as lazy as you say, then you might like a computerised goto scope. But that's still more money. If you have a smart phone or tablet, you may be able to set it up as a guidance computer (by using something like say SkEye). But then if you are really that lazy, you will not do the reading and work required to set it up. :P

OTOH, with a small scope under suburban skies, your targets worth chasing will be few: the Moon, Saturn, Jupiter, rarely Mars and Venus, few dim deep sky objects, and maybe a double star and open cluster here and there. There is no point having a goto scope when most of what it goes to is barely visible specks or smudges of light. :(

So perhaps a 4" ED / semi-apo refractor or a 5-6" Mak on a solid AZ mount would suit you best?? :question:

Good luck! :thumbsup:

[mbyrr]

Any tips?

My finder doesn't seem to be setup properly also. :question:

The first night I took it out I found a big bright shiny red thing, no idea what it was, but I never found it again. I have since aspired to find something like that but have had no such luck, I'm not sure if it's due to bad collimation or the fact I'm just terrible at finding things. :sadeyes:

It seems that I should give this dob a further chance... I really like the sound of GoTo tho admittedly, it must make finding the things you're looking for sooo much easier! :lol:

[GeoffW1]

Hi,

There is this one for sale, a bit more $ but you could maybe bargain. Reasonable aperture, very portable, no collimation, and you could fit pushto or goto later on (eg Argo Navis).

http://www.astrobuysell.com/au/propview.php?view=2285

Cheers

[dannat]

in a courtyard the refractor would be the best option imo - one thing i would get is a good alt/az mount -i prefer the maual type, quicker & no need of batteries or waiting for slewing,
a 4" f9 ED doublet is a vry good scope, youll be lucky to get one for 500 used then you need an alt/az munt +200-300 to go with

[janoskiss]

Find someone who knows how to do it and learn from them. Take your scope to one of the public viewing nights of an amateur astronomy club near your place. Mornington Peninsula Astronomical Society would be a good choice. People there will be very happy to help you get the most out of your scope as well as help you find the scope that suits you best.

[mbyrr]

Well I just spent a few minutes collimating the dob, following a tutorial video I found on YouTube.

I can't find anything about setting up the Finder properly tho, anyone?

[GeoffW1]

Hi,

This worked for me...

Mount your lowest power EP and in the daytime at twilight, swing to a distant distinctive object on land. In my case there was a lady used to sunbathe on her balcony........um, she was upside down tho.

Focus the finder and scope for that distance and centre the object in the EP. See where it is in the finder and centre it there as well.

This will nudge it out of the EP so repeat all this. Then mount a medium power EP and repeat again.

Wait now for a bright star to appear (no confusion with others then) and do all that again on the star. If you have to refocus the finder do so carefully as it is easy to push it out of alignment.

Then go to your highest power EP and repeat.

Cheers

[mbyrr]

Thanks Geoff. I got it centered on a signpost across the street but will need to do it on a star for proper alignment I imagine.

I'm seeing alot of talk re the Telrad Finder, it sounds like a good investment, is it?

[noeyedeer]

best to use something a few kms away. across the street will have your finder wayyy out

[mbyrr]

Yeah it was wayyy out already. :thanx:

So after some consideration of everyone's much-appreciated comments, I'd really like to make the dob work. To that end, if I can make it easier to use that would entice me to use it more often. Consequently:

1. Any recommendations for this Telrad finder? I watched a video about it and it seems to be highly recommended for finding things (one of my issues).

2. Another upgrade option is a 2x Barlow. I noticed that Bintel have a couple of branded options, the ED and non-ED version. Is it worth it for planetary viewing?

3. I saw a video on YouTube where a guy attached a webcam, has anyone tried that? I took some pics of the moon awhile ago, but it was a pain to line the camera up to the EP. :ashamed:

[dannat]

i personally dont like using barlows too often,but for planetary they are ok -the ED versions can degarde the image less

telrad is good -you dont like the optical finder? both have ADV/DISADV, some peole use both

webcams can work -to take pics or live view?

[mbyrr]

Yeah I was thinking of using both.



Either/or I guess.
I saw a video of a guy converting a Creative webcam with a film cannister, seemed like a cheap and easy way to get the job done.

[mbyrr]

Hmm it seems I've managed to align my finder using Syrius.
I really like this SkEye app on my phone too :D

[barx1963]

Sirius, good choice for finder aligning.
Telrads are either a love em or hate thing. I have used one but gave it away as it dewed up very easily and craning the neck is a pain. Some use them very succesfully with no other finder but I only used them to sentre on brigh naked eye stars then use my main finder to star hop. One advantage to living in the bush is green lasers are a bit less obviou here so I prefer that to a Telrad, but in the city it may be you best choice.
A comment on collimation. I was reading another guide today (see here http://www.garyseronik.com/?q=node/169 ) which has a little FAQ section that explains what collimation achieves and puts things into perspective. The lesson is that a scope that is a little out will still work OK, just you may lose a little light and get more aberrations. But perfect collimation is not such a big deal (at least for visual observing).
And a further comment on goto. Many think that Goto will solve all their issues with finding objects. IMHO it is often a false economy. In mosr case you still have to align the scope each time you setup which requires some basic knowledge of the sky. I found when I used a goto for a little while I spent more time fiddling with aligning and setuo than actual observing. I would setup, do the alignment, then slew to some bright familiar object, not be happy with the accuracy so start again, make a mistak, start agin and 45 minutes would go by and all I have seen are a couple of alignment stars and one bright object. In that time I could have nabbed 5 or six objects with my dob!
Also with go to you are trading aperture away for electronics.
This is not to say that goto has no uses, but it is not a panacea.

Anyways, glad to hear you are persisting with the dob and making progress!!:thumbsup:

Malcolm

[barx1963]

Oh and a note on barlows. Some recommend them on the basis that it doubles your eyepiece collection.
I used a Televue 2x Barlow for some time and well as a Televue 2.5x Powermate and frankly never saw better images with them than I could get with an equivalent stand alone EP.
I tried numerous times but always went back to stand alones.
Good quality EPs are the "gift that keeps on giving" they are an investment is future viewing taht will outlast your scopes if you look after them. IMHo they are a much better investment than barlows.

Malcolm

[mbyrr]

Yes I might wait on the Telrad for now, at least I have an aligned finder now, so that helps!
If not a barlow, what other sizes should I get to complement the ones I already have? (15mm and 9mm Fully Multi-coated Plossl Eyepieces (1.25"), 26mm Wide View Eyepiece (2"))

[barx1963]

Plossls tend to be OK at the longer lengths. The 26 and the 15 should be fairly easy to use. In your scope they will give 38x and 67x respectively and the 9 will give 111x. In most situations you do not need much over 100x and in an 8" pushing much beyond that on most nights is asking a bit.
So I would persist with the EPs you have and try to do as much with the lower power ones as you can. Best thing is to try and get to observing nights and ask to try others eyepieces. In most cases, observers are happy to oblige and it will give you a good idea what works.
I know it is a bit in the future but as you are in Melbourne, think about coming up to the Snake Valley camp, first weekend in November. We are a very friendly bunch and you will get to see losts of scopes and try lots of eyepieces. The website is here http://ballaratman.wix.com/svaa#!events The other suggestion of the MPAS is good also.

Malcolm