How would you spend £500?

[Scytale]

My wife bought me a Celestron Travelscope 70 for Christmas, which is great because it's got me obsessing about stargazing. But it's also quite challenging working with it, and I feel I'm outgrowing it very quickly. I've started thinking about buying myself a new scope, maybe an 8" Dob.

How would everyone here spend £500? Which scope would you choose and what eyepieces and accessories would you buy?

[alanjgreen]

Scytale,

if you want goto (and I think it's great for a beginner) that would allow you access to endless objects with a guarantee that they will be in the eyepiece straight away. Spending all your time observing then I would consider

https://www.firstlightoptics.com/reflectors/sky-watcher-star-discovery-150p.html

with my remaining budget, I would get a decent red dot finder

https://www.firstlightoptics.com/finders/baader-30mm-sky-surfer-iii.html

A UHC filter

https://www.firstlightoptics.com/uhc-oiii-visual-filters/skywatcher-uhc-filter.html

and a couple of BST eyepieces 

http://www.365astronomy.com/15mm-BST-Explorer-ED-Eyepiece.html

The scope has goto and therefore has tracking too, meaning objects just stay in centre of view and you sit and observe. Heaven!

 

however, if you don't mind a manual (no help finding and no tracking) scope, then my 500 would go like this

8" dob ( 77% more light gathering than the 150p)

https://www.firstlightoptics.com/dobsonians/skywatcher-skyliner-200p-dobsonian.html

telrad finder

https://www.firstlightoptics.com/finders/telrad-finder-astronomy.html as I now need a finder to find the stuff (there is no goto). Telrad circles will ease this significantly.

i would still get the UHC filter linked above

i would buy a 11 or 14mm ES 82 degree eyepiece to max the wide view available in the dob.

https://www.firstlightoptics.com/explore-scientific-eyepieces/explore-scientific-82-degree-series-eyepieces.html

remember, the dob has no tracking of objects, you need to let the objects drift across the view. The 82 degree eyepiece makes this a breeze and reduces the need to keep "nudging" the scope to track the object.

you can add further eyepieces later...

 

[Steve 1962]

I'd buy the best Dob that £500 would buy (would you get a 10" for that amount maybe??) and draw up a list of dream eyepieces as a future Christmas and birthday present list.

Steve

[alanjgreen]

Yep, the 250px 10" dob is £429 so in budget. (56% more light than an 8")

https://www.firstlightoptics.com/dobsonians/skywatcher-skyliner-250px-dobsonian.html

if i could stretch to the telrad and a decent 82 degree eyepiece then that would be on my choice list too

you can add the filter later for sure.

Just check the weights of the scopes. I think the sizes are pretty similar.

 

[Charic]

1 hour ago, Scytale said:

How would everyone here spend £500? Which scope would you choose and what eyepieces and accessories would you buy?

From our sponsor the £285  8" 200P Skywatcher Skyliner is a great buy, great scope too, under the right conditions,  and  with change to buy some  eyepieces  similar to those in my signature, the  Starguiders from ebay are my recommend!

A bigger scope will offer more in performance, so for my next scope, I would like the 12" Skyliner ( no longer produced)  but their Skyliner 250PX at £429 from Flo again is good value, and again under the right conditions should perform a little better than my present scope, due to the larger aperture. 

Neither scope is automated, got to do it all yourself, but that just means simplicity in setting up,  ease of use, great results. 

If/when I get a chance to look through a bigger  scope, the urge may return, but for now, the 8" 200P is a keeper.

[John]

As long as you are willing to find targets yourself and track them manually, I think the 8" F/6 dobsonian offers tremendous performance per £ spent. Get a Telrad finder plus a few BST Starguider eyepieces plus a good star atlas and you have the gear for many years of  observing pleasure

 

 

[Chris]

AS said, get the 8" Dob and a couple of good eyepieces, plus Telrad. They are so quick to setup, easy to use, and represent the most aperture per £. 

[Putaendo Patrick]

Personally I'd stick with a fixed tube 8" Dob for the moment. Larger aperture will certainly allow you to see fainter objects, but larger Dobs also have certain disadvantages. They have a faster focal ratio (the telescope's focal length divided by aperture in millimeters) which means certain less expensive eyepieces will perform less well. Larger Dobs also usually (but not always) have a collapsible truss system which will need more frequent collimation (fine-tuning the alignment of the mirrors). Add the extra weight and physical size, the larger 10" Dobs are getting towards the upper limit of what one person can set up easily. Larger may be better but smaller may mean the telescope gets more use!

An 8" Dob is a superb all-round manual observing telescope - and price-wise it is unbeatable. In the future, you may develop interests in observing certain types of objects and other designs or sizes of telescope may be more appropriate. But you may also find an 8" Dob will serve you very well for many years of stargazing. If you're not in a hurry to buy, keep an eye out for second-hand - you should be able to find a good example for about 200 pounds, maybe less.

With any larger reflector telescope you will probably want to buy a Cheshire eyepiece for collimation, about 30-35 pounds - usually much better than cheaper laser collimators. Collimation, by the way, is not at all difficult with a little practice.

Many 8" Dobs will come with two eyepieces supplied in the box - typically a 25mm (giving a magnification of x48 based on a focal length of 1200mm) and 10mm (giving x120). Generally the lower power EP will be acceptable to start, the higher power however is often less brilliant and you may want to upgrade quite quickly. Most types and makes of EP will work well. Plossls start at about 25 pounds - but do have quite a narrow field of view (50°). BST Explorers or Starguiders (the same EP is branded under several different names) is wider at 60° and costs about 45-50 pounds. More expensive but excellent are the Explore Scientific 68° and 82° lines. Again, with patience, there are very good value offers second-hand - most astronomers keep their eyepieces in very good condition. I think all new 8" Dobs allow you to use 2" and 1.25" diameter eyepieces - the larger diameter can give really spectacular wide views at low magnifications.

 

 

[RobertI]

8 hours ago, Scytale said:

My wife bought me a Celestron Travelscope 70 for Christmas, which is great because it's got me obsessing about stargazing. But it's also quite challenging working with it, and I feel I'm outgrowing it very quickly. I've started thinking about buying myself a new scope, maybe an 8" Dob.

How would everyone here spend £500? Which scope would you choose and what eyepieces and accessories would you buy?

Some excellent suggestions above. Just in case there is anything we have missed, what is it you were finding challenging about the Travelscope 70?

[Ben the Ignorant]

Big dob now. Widefield eyepieces later.

[ollypenrice]

Do big truss Dobs require frequent collimation? I've only ever had one, our present 20 inch F4.1, and it stays in a fixed location under a roll off shed. It's also quite old and, perhaps, settled and stable, but it hardly ever needs collimating. It's important to remember that the Serrurier truss is a very clever, though simple, design which deforms almost harmlessly from an optical point of view.

Olly

[Scytale]

Thanks for the replies everyone.

Goto would be nice, but I've generally done ok so far with finding things. Usually if I fail to find something, then when I check Stellarium on my PC then I quickly see where I've gone wrong. (I still need to get it set up on my phone). Tracking can be a bit of a pain with the TS70 mount, but I'd hope this would be easier with a Dob.

alanjgreen, you've recommended a similar magnification eyepiece to the one that comes with the 200p. Do you think this would be more use than a different magnification eyepiece? Or is the one that comes with the scope worth replacing immediately?

 

Just noticed that the focal length is the same on both the 200p and 250p. I had assumed a 10" scope would also be 25% longer and a bit too unwieldy, but maybe it's not

 

5 hours ago, RobertI said:

Some excellent suggestions above. Just in case there is anything we have missed, what is it you were finding challenging about the Travelscope 70?

The issues are with the mount mostly. At most azimuth angles the tripod legs get in the way of the knob for tightening the altitude setting when looking at objects high up. I've tended to just rotate the whole mount on the tabletop with the azimuth tightened. It's also unbalanced on the mount when pointing high up so I need to tighten the altitude setting, and the angle changes when you tighten the knob. So I have to aim below the object I want to look at and then tighten the knob to try to get it centred in the eyepiece. Or put something under one of the legs to correct for the shift.

It's not particularly stable either, which makes it tricky to get it precisely focussed because the image wobbles when you adjust it.

It came with a 45deg diagonal, which means I need to kneel on the ground to observe objects that are high up.

I could buy a new mount and star diagonal (which I may well do, as it's very portable and I'll likely take it on holidays), but I suspect I'll want to upgrade soon anyway.

[happy-kat]

I'll just add the star discovery mount has freedom find which means it can work with no power fully manually, or track, or go to with the goto one.

If there are stairs between storage and observing location a big dob might be a nuisance to move, only you know what you are prepared to log about.

[Louis D]

1 hour ago, Scytale said:

The issues are with the mount mostly. At most azimuth angles the tripod legs get in the way of the knob for tightening the altitude setting when looking at objects high up. I've tended to just rotate the whole mount on the tabletop with the azimuth tightened. It's also unbalanced on the mount when pointing high up so I need to tighten the altitude setting, and the angle changes when you tighten the knob. So I have to aim below the object I want to look at and then tighten the knob to try to get it centred in the eyepiece. Or put something under one of the legs to correct for the shift.

All non-issues with the dob mount.  It is kinetically stable at all angles and doesn't require any axis locks.  You can overload the front end with heavy eyepieces, but this can be counteracted with counterweights at the back end.

1 hour ago, Scytale said:

It came with a 45deg diagonal, which means I need to kneel on the ground to observe objects that are high up.

The angle of the eyepiece is basically always in a convenient location at the front of the tube, pointing slightly upward so even loose eyepieces won't fall out.

 

1 hour ago, Scytale said:

Just noticed that the focal length is the same on both the 200p and 250p. I had assumed a 10" scope would also be 25% longer and a bit too unwieldy, but maybe it's not

The 10" has a shorter focal length, which means more critical collimation, and it is more demanding on eyepieces due to the steeper light cone.

 

1 hour ago, Scytale said:

Tracking can be a bit of a pain with the TS70 mount, but I'd hope this would be easier with a Dob.

With a bit of practice, tracking becomes quite natural with a dob.  A little nudge up or down and a nudge to the side, repeat.  That's why wide fields are popular with them, so you have more linger time to observe between nudges.

If you want goto with an 8" dob, your best bet is the Skywatcher Skyliner 200P FlexTube GOTO, but that breaks your budget.  It and its larger brethren are becoming quite popular here in Texas at star parties.  They seem quite capable both optically and GOTO-wise.

[RobertI]

3 hours ago, Scytale said:

Thanks for the replies everyone.

Goto would be nice, but I've generally done ok so far with finding things. Usually if I fail to find something, then when I check Stellarium on my PC then I quickly see where I've gone wrong. (I still need to get it set up on my phone). Tracking can be a bit of a pain with the TS70 mount, but I'd hope this would be easier with a Dob.

alanjgreen, you've recommended a similar magnification eyepiece to the one that comes with the 200p. Do you think this would be more use than a different magnification eyepiece? Or is the one that comes with the scope worth replacing immediately?

 

Just noticed that the focal length is the same on both the 200p and 250p. I had assumed a 10" scope would also be 25% longer and a bit too unwieldy, but maybe it's not

 

The issues are with the mount mostly. At most azimuth angles the tripod legs get in the way of the knob for tightening the altitude setting when looking at objects high up. I've tended to just rotate the whole mount on the tabletop with the azimuth tightened. It's also unbalanced on the mount when pointing high up so I need to tighten the altitude setting, and the angle changes when you tighten the knob. So I have to aim below the object I want to look at and then tighten the knob to try to get it centred in the eyepiece. Or put something under one of the legs to correct for the shift.

It's not particularly stable either, which makes it tricky to get it precisely focussed because the image wobbles when you adjust it.

It came with a 45deg diagonal, which means I need to kneel on the ground to observe objects that are high up.

I could buy a new mount and star diagonal (which I may well do, as it's very portable and I'll likely take it on holidays), but I suspect I'll want to upgrade soon anyway.

I suspected these were the reasons and I totally sympathise! As @happy-kat says, a Dob will solve all these problems. 

[happy-kat]

Not me I'm not a fan of anything too big to get outside with easy

[RobertI]

1 minute ago, happy-kat said:

Not me I'm not a fan of anything too big to get outside with easy

Sorry meant @Louis D!

[alanjgreen]

7 hours ago, Scytale said:

 

alanjgreen, you've recommended a similar magnification eyepiece to the one that comes with the 200p. Do you think this would be more use than a different magnification eyepiece? Or is the one that comes with the scope worth replacing immediately?

 

Hi Scytale,

You are correct, but the fact you have a freebie or two did not come into my consideration. If you are buying one or two "great" eyepieces then best to make them your "most used" eyepieces. If you buy expensive but rarely used eyepieces to avoid clashing with some "freebie" eyepieces then is that a sensible approach? If I had great eyepieces then I would want them in the scope with me looking through them as much as possible

 

generally, I find that an eyepiece around x100 and another around x150 would be "heavily used"

 

both 200p and 200px have focal length of 1200mm

so a 14mm will give x85 and an 11mm will give x109 (and 8.8 gives x136) magnification.

 

If I was buying one then I would go with the lowest mag as the first purchase (so 8.8mm), then add the 14mm later

I do believe 82 degree eyepieces work great in dobs (for the reasons stated in my first post)

I looked at the ES82 prices and see 8.8,11 & 14 mm at around £100 each. If you plan long term then 8.8 (x136) & 14 (x85) could work in the same set (you ideally want x50 mag between each eyepiece so that excludes the 11mm - you dont need it as its too close to the other 2)

So, I would go 8.8 to start (there changed my mind with some calculations)

Anyway, you see the thought process...

Long term, you need magnifications of 50, 100,150,200,250, (to be well covered for all conditions), out of these I find (as a galaxy & dso kind of guy) that 100 & 150 are my "most used"

The x50 may well be a 2" eyepiece and these are £200 so not in your £500 budget right now.

HTH,

Alan

[rockystar]

I'd personally go for the 14 first and the 8.8 second . My 14 is far and away my most used eyepiece - there are sessions when it never leaves the scope. Each to their own, and you would need to work it out yourself unfortunately.

I would spend £500 on an 8" dob, telrad, 14mm Es 82 degree, turn left at Orion, red torch and sky &scope star atlas.

 

[wookie1965]

Second hand HEQ5

 

[niallk]

23 hours ago, Steve 1962 said:

I'd buy the best Dob that £500 would buy (would you get a 10" for that amount maybe??) and draw up a list of dream eyepieces as a future Christmas and birthday present list.

Steve

 

22 hours ago, alanjgreen said:

Yep, the 250px 10" dob is £429 so in budget. (56% more light than an 8")

https://www.firstlightoptics.com/dobsonians/skywatcher-skyliner-250px-dobsonian.html

if i could stretch to the telrad and a decent 82 degree eyepiece then that would be on my choice list too

you can add the filter later for sure.

Just check the weights of the scopes. I think the sizes are pretty similar.

 

+1 

[Scytale]

 

On 24/01/2017 at 19:39, alanjgreen said:

You are correct, but the fact you have a freebie or two did not come into my consideration. If you are buying one or two "great" eyepieces then best to make them your "most used" eyepieces. If you buy expensive but rarely used eyepieces to avoid clashing with some "freebie" eyepieces then is that a sensible approach? If I had great eyepieces then I would want them in the scope with me looking through them as much as possible

Ok, that makes sense.

Thanks for the replies everyone. I think I'd definitely want one high quality eyepiece, and the budget is somewhat flexible so I just need to decide how large a scope I am comfortable with.

I'll not be rushing, as I'll need to wait an appropriate period of time before I effectively replace what was a Christmas present.

[nicks90]

Personally I would get a second hand 8" dob and spend the rest on a 24mm es explorer 82mm EP and a 11mm es explorer 82mm EP and an Antares x1.6 2" Barlow.

Gives you amazing low powered views with the 24mm all the way up to effectively a 7mm using the barlow and 11mm ep.

Should just about come in budget and will last you a lifetime.