Dobsonian to something else?

[mbyrr (Antony)]

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/...oductview.aspx

http://www.bintel.com.au/Telescopes/...oductview.aspx

Thanks heaps!

cheers
A

[barx1963 (Malcolm)]

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!! 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 (Joe)]

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

[naskies (Dave)]

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 (Chris)]

Originally Posted by moonunit

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

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

[Larryp (Laurie)]

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 (Paula)]

Originally Posted by moonunit

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

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/skywatche...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

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

Cheers
Steffen.

[barx1963 (Malcolm)]

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 (Brent)]

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 ... ) just to cover all my options. You never know when the beast will awaken and summon you to look up again.

[RobF (Rob)]

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 (Steve H)]

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 (Antony)]

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).

[barx1963 (Malcolm)]

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/collimatio...on%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!!!
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 (Steve H)]

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.

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??

Good luck!

[mbyrr (Antony)]

Originally Posted by janoskiss

got her a better finder, learnt how to keep it collimated precisely...

Any tips?

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

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.

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!

[GeoffW1 (Geoff)]

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 (Daniel)]

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 (Steve H)]

Originally Posted by mbyrr

Any tips?

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 (Antony)]

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?