Starter telescope, how big is big and other question

[flymetopolaris]

1) Want to get an 8 inch dobsonian as a minimum but how big/heavy are they and is it possible to move it into my garden by myself from my dining room? I have a shed outside but its not very secure so I keep nothing of value in there.

I assume setup time is a lot shorter then using an EQ mount, this is my main reason for using it, as well as price wise

2) Is there real advantage to a truss dob or even an auto tracking one? £280 for a dob or around double that for the auto truss

3) Is it hard to track the sky with a dob, I was thinking I could use stellarium as I've been tinkering with it a while now to help, in the long run does it hurt your enthusiasm?

4)Also, how hindered will my enjoyment be if I will only be able to see from my back garden, I do not drive or anything, no dark skies near me...

Thanks

[John]

Hi and welcome to SGL

MY observing circumstances seem very similar to yours (ie: scopes kept in dining room, need to be moved into garden to observ, then back again). To answer your questions:

1) ....how big/heavy are they and is it possible to move it into my garden by myself from my dining room? I have a shed outside but its not very secure so I keep nothing of value in there.

An 8" dob weighs around 40lbs in total - I could carry mine in one piece out of the french windows and onto the lawn pretty easily. The tube is around 4 feet long / high (when pointing up !) and the base is around 20 inches across.

I assume setup time is a lot shorter then using an EQ mount, this is my main reason for using it, as well as price wise.

Setting the scope up takes a few seconds. They need 20-30 mins for the tube / mirrors to cool before use.

2) Is there real advantage to a truss dob or even an auto tracking one? £280 for a dob or around double that for the auto truss

In sizes less than 12" a truss design has no advantages, solid tube holds collimation a bit better in fact. Personally I find "nudging" quite easy, when you get used to it, at high power.

3) Is it hard to track the sky with a dob, I was thinking I could use stellarium as I've been tinkering with it a while now to help, in the long run does it hurt your enthusiasm?

See my previous reply - personally I prefer the convenience / ease of use over tracking.

4)Also, how hindered will my enjoyment be if I will only be able to see from my back garden, I do not drive or anything, no dark skies near me...

I drive but, apart from the SGL star party's I do all my observing from my back garden. I have some light pollution but I can move the scope around to dodge the worst of it !.

Hope that helps

[Demonperformer]

The main disadvantage of a dob is that it cannot be used for photography. However, if you get a standard (non-truss) dob, there is no reason why you would not be able to mount the OTA on an EQ mount at some later date.

Go for it.

[ollypenrice]

Impossible to say how bad your light pollution is at a distance but an 8 inch Dob will be a cynch to move around and a great choice, in my view. However, computers, for me, are a necessary evil when imaging. They clonk your night vision whatever you do with red cellophane! For visual observing, better to get a good paper chart book like SkyAtlas 2000 by Wil Tirion. I can't cope with the small print of Norton's or the small Cambridge Atlas. It is such a pleasure by day as well, or on cloudy nights. Of course the computer planetaria are great in the house, too.

Olly

[Moonshane]

I agree with John and demonperformer of course. I would add that an 8" newtonian / dobsonian is a great starter scope and will serve you really well. the eyepieces that come with it will be fine fore some time. if you don't get a barlow with the package, try to negotiate one if buying new or certainly get one if they won't budge. a telrad/quikfinder will be a very good addition and makes initial placement of the scope in the sky far easier.

I'd certainly recommend buying used as you can get some real bargains off this forum if you wait a little.

the scope can be moved in two bits if 40lbs is a bit heavy for you. also, collimation of the tube is something you'll need to learn but it's a snip to get it good enough for visual work so don't be worried about it. I collimate my dob every time I use it in less than a couple of minutes.

finally, when you eventually move on in the hobby as you inevitably will, it's a good step to go from 8-12" dobsonian and maybe 2-3 great eyepieces will make the world of difference with a faster scope like this.

overall I agree - go for it, you won't regret it.

[acey]

1) Want to get an 8 inch dobsonian as a minimum but how big/heavy are they and is it possible to move it into my garden by myself from my dining room?

Great choice, it's what I started with too. When I first got it I thought it was huge, but I could carry the whole thing, tube plus base, with one hand, so it was easy to move in and out of the house and around the garden.

2) Is there real advantage to a truss dob or even an auto tracking one? £280 for a dob or around double that for the auto truss

No, stick with solid tube.

3) Is it hard to track the sky with a dob?

No, as long as you don't go to ridiculously high power. I go up to x375 with my dob and that's pretty high. x200 will show a lot of planetary detail.

4)Also, how hindered will my enjoyment be if I will only be able to see from my back garden, I do not drive or anything, no dark skies near me...

Light pollution has no effect on Moon and planets. You should get good views of lots of star clusters, and although a dark sky will always give the best views, it's possible to see some galaxies from a light polluted site - just don't expect them to be more than little fuzzy patches. There are quite a lot of nebulae that can be seen well from a light-polluted site: I had my first view of the Ring Nebula from my suburban garden with an 8-inch and thought it awesome.

[russ]

The others have covered all your questions in detail and i agree 100%, so all i'll do is give a double thumbs up to the 8" dob. You won't be disappointed!

[Macavity]

3) Is it hard to track the sky with a dob, I was thinking I could use stellarium as I've been tinkering with it a while now to help, in the long run does it hurt your enthusiasm?

I don't think computers will "hurt your enthusiasm". You may get to like (or not like) their role in astronomy - Or alternatively, view them with some degree of equanimity. Learn to star hop AND use a computer? You can then do either, depending on conditions, or mood...

Since you are familiar with Stellarium, you can of course click on objects and display their Alt-Azimuth coordinates. You can then use these to point the scope manually to within at least a finder-width accuracy. Checkout how other Dob users have made an azimuth scale around the telescope base and use e.g. a Wixey angle gauge to read off the altitude coordinate. Quieter than a GoTo - you can always use Stellarium's (red) night mode for less impact too.

[flymetopolaris]

Hi all, I did notice a gizmo that you stick to the telescope an it knwos the altitude, which could be handy?

1)I was considering stretching my budget to a 10 inch skyliner if need be, but is this too big for a starter scope and is there a huge difference between the two? Online forums suggest there isn't much between the two but surely if there is a rough 50% larger aperture it should be a lot better?

2) The 10 inch is described as having a pyrex lens, what advantage is this?

How big is it in size, weight?? I havent seen a dob in person but I'd like to think I could lift it with my huge muscles...

Aperture fever, yet I haven't even bought a telescope before

[Cornelius Varley]

According to the Sky-watcher Telescopes site the 200P OTA weighs 7.98kgs and the 250P OTA weighs 12.42kgs. TELESCOPE SUPPLIERS - SKY-WATCHER TELESCOPE

Peter

[pvaz]

On the chart book, I would recommend pocket sky atlas as it's good, cheap and haves all the objects you can aspire to observe with an 8".

I can also recommend an 8" dob as it haves a nice blend between aperture, portability and cost. I got one and plan to keep it. I may get a bigger one later when I use mine to it's limits, but I still have a long way to go before I can say I've done that.

PS-> a telrad finder (or a rigel quick finder, though I think the extra circle on the telrad gives it an edge) and at least 200 stars visible naked eye are needed to make starhoping easy. If you have too much light pollution you may need binos to find the location before pointing the scope.

[Demonperformer]

Hi all, I did notice a gizmo that you stick to the telescope an it knwos the altitude, which could be handy?

1)I was considering stretching my budget to a 10 inch skyliner if need be, but is this too big for a starter scope and is there a huge difference between the two? Online forums suggest there isn't much between the two but surely if there is a rough 50% larger aperture it should be a lot better?

2) The 10 inch is described as having a pyrex lens, what advantage is this?

How big is it in size, weight?? I havent seen a dob in person but I'd like to think I could lift it with my huge muscles...

Aperture fever, yet I haven't even bought a telescope before

I used to own a 10" dob and it was big, too big to get into the car, also my home situation was such that it was not suitable for use there. Ended up having to sell it on.

The Wixey alt meter is great - just got one to replace the rdf on the 6SE which I found impossible to get on with. Digital Angle Gauge with magnetic Base

[Tinners]

How big is it in size, weight?? I havent seen a dob in person but I'd like to think I could lift it with my huge muscles...

...most dobs come in two halves...

[kniclander]

a 10" dob will be much more sensitive to collimation than an 8". At F4.8 you have to be pretty much spot on; at F6 you can be quite a bit out and it won't harm the view.