Help Deciding on a Scope Please.

[GaryL]

Hi All,

     wasn't sure whether to post this here or in scope discussions so hope here is ok.

 I've found myself suffering a bout of "aperture fever" just lately and would like to upgrade from my SW 130P.

I have about £400 to spend and would like to stick with a reflector. My first thought was to get a SW 200P EQ5 but then I happened to peruse the Dobs and saw that the 250PX is only another £20 for an extra 2" of aperture.

Ever since I've been umming and aahing over which to choose and have ended up with a list of pro's and cons the big pro for the dobs obviously being it's extra light gathering capacity but I do have concerns over some of the dob "cons" and would really like some advice from some of you dob owners. 

 I appreciate that the best thing to do would be to go and have a look at one in the flesh, but there are no scope outlets or nearby astro clubs near here and I don't have a car. 

I'm only interested in visual astronomy so I don't need to worry about tracking for imaging.

My concerns about choosing a dobsonian are as follows :-

 My small yard (where I do all my observing) is a concrete slope of about 10-15 degrees. How difficult is it to level and stabilise the base?

 I understand that object tracking is done manually, and I'm guessing there's an art to it.How tricky is it and will my BST Starguiders at 60 degree FOV be ok ? (I've seen some people recommend 82 degree to keep the target in view longer).

 My partner is 5' 2", how easy will it be for her to use the eyepiece and what do people find is the best way to get comfortable whilst viewing?

 I've read that dobs due to the nature of the mount have a problem viewing at Zenith, my small yard is surrounded by fairly high walls and trees so a lot of my observing is done at fairly high angles, how much of a problem is this?

Any and all help and advice would be very much appreciated.

Thanks in advance.

Gary.

[ScottS]

It is true that viewing at or near zenith is a bit tricky and Dobs are always bigger than you think they are going to be, but if all you are interested in is visual astronomy they are hard to beat.

[GuillermoBarrancos]

Never buy a large reflector on an EQ mount, if you only going to use it for visual observation!

As the eyepiece can get on some really uncomfortable positions.

If you got Aperture fever, go for the largest you can afford. A dob gives you best bang for buck, when it comes to aperture.

So the 250px seems like a good choice.

A lot of people on this forum swear by a 10inch dob being the so called "goldy locks" size.

[jimbooz]

Hi Gary

I've had a 200p dob for just over a year and I love it (my first scope). To answer some of your questions:

 My small yard (where I do all my observing) is a concrete slope of about 10-15 degrees. How difficult is it to level and stabilise the base?

The bases are wooden with small 1cmish rubber "legs". A little bodging will get you a level base easily enough. I've even used mine on a slight slope and as long as you are wary not to tip the whole scope it has been fine. Set up time is minimal. I can lug my dob in one piece from the shed to the patio and the rest of my kit from the house and I can be observing in less than 5 mins.

 I understand that object tracking is done manually, and I'm guessing there's an art to it.How tricky is it and will my BST Starguiders at 60 degree FOV be ok ? (I've seen some people recommend 82 degree to keep the target in view longer).

I started with the stock eps and you soon get the hang of nudging. It becomes second nature after a few nights observing. Even coming back to it after a summer hiatus was OK. Its liek riding a bike! Finding bright objects is fairly easy. With an aligned finderscope my little lad found Jupiter through the eyepiece in less than 2 minutes. Fuzzies require more persistance and a star guide (Turn Left at Orion is great) and there is a great sense of satisfaction in tracking them down.

 My partner is 5' 2", how easy will it be for her to use the eyepiece and what do people find is the best way to get comfortable whilst viewing?

My kids are 8 and 10 and have no trouble. The best way to get comfy is a padded stool. Drum stools are supposedly great. I make do with the largest of a nest of side tables and a large cushion. The wife threw the stool out last summer

 I've read that dobs due to the nature of the mount have a problem viewing at Zenith, my small yard is surrounded by fairly high walls and trees so a lot of my observing is done at fairly high angles, how much of a problem is this?

The dob is tricky at zenith. Viewing is no problem but its lining the scope up with the straight through finderscope which is tricky. You have to contort your body quite a bit. However, there are a limited amount of objects at or near zenith which are difficult and as you go through the evening these objects are rotating into "easier positions" anyway.

Being a bit of a newbie I've not had much experience with other types of scope but hopefully this helps.

Jim

[GaryL]

Thanks for the replies guys and thanks for such a comprehensive reply Jim. It seems to me from all I've read on here that people absolutely love their dobs and I think we're definitely veering in that direction.

 We were out last night and tracked down and got a gorgeous view of M67 it was such a thrill to pick it out from Stellarium and then track and actually find it, and personally I've been observing M3 and the great cluster in Hercules lately, so DSO's seem to be what we really get a kick out of, another good reason to go with the larger aperture I imagine.

[clarkent]

Since we can't view the buy&sell here, don't forget to check out sources like AstroBuy&Sell for used Dobos.

There is a flextube version of the 250px still active: "Skywatcher Skyliner 10" 250px Dobsonian Telescope  Ad# 78333 ". 

 

[GaryL]

Dob ordered     

[swamp thing]

Good call Gary

The slope of your back yard will actually help when you view at the zenith. This "Dob hole" that you've heard about can be overcome by doing exactly what your slope is doing for you. If I'm viewing at the zenith I place an object under one foot of my Dob to deliberately tip it out of level. Hey presto, no Dob hole at the zenith. Your yards doing that for you happy days buddy

HTH

[jimbooz]

You'll love it

[wolfpaw]

My current experiences with my 250PX would lead me to advise you getting the 200P instead. Your BST eyepieces will give sharper images in the 200P across the field of view and you might well be very disappointed with how they perform in a 'faster' scope. The 250PX is harder on eyepieces and if, like me, you find the appearance of coma/aberration across much of the FoV objectionable then you're looking at spending x amount of pounds on a coma corrector. The 200P is lighter. Easier on eyepieces. Less fussy about collimation. Yes, the 250PX has a larger aperture but it's also heavier and you need to keep in mind that you'll have to spend more on eyepieces and possibly a coma corrector. Also, I remain to be convinced how obvious the difference is between an 8'' reflector and a 10'' reflector compared with the difference between an 8'' and a 12''.

If I had the money in my bank account again then I would get a 200P.

Good luck with whatever you decide

[wolfpaw]

Edit: Sorry, didn't realise you'd already ordered one. I'm sure you'll have fun with it either way

[clarkent]

Good luck with your Dob

[GaryL]

Well, my Dob arrived yesterday (4.00 pm so it was a bit off a mad scramble getting assembled as the forecast looked pretty good). 

Actually did't come packed in clouds for once   So at dusk it was straight out the back. First thing I noticed was how quick and easy it was to setup. It is a weighty chap, but not too bad really ( all those work outs are finally paying off) and I was out and at the eyepiece in a little over 5 minutes I would guess. There was Jupiter high in the sky, so I lined myself up and was just completely blown away by the view 

I removed the straight through finder and fixed a Telrad in it's place, got myself a comfy chair and only came in at about 1 am when I couldn't feel my fingers anymore 

What can I say other than this 'scope is an absolute delight to use.

I'd like to thank all of you for your help in choosing, I feel I've found an instrument I can cherish and use for many years to come.

Cheers All.

Gary.

[rwilkey]

Well done Gary, welcome to the pleasures of stargazing!

[GuillermoBarrancos]

Which one did you buy? The 250PX?

[GaryL]

Which one did you buy? The 250PX?

Yea, I went for the 250PX in the end, and very glad I did too 

[GuillermoBarrancos]

Nice buy!

I have the Orion SkyQuest xx12g on my future wish list.