Used 10" Dobs are fairly rare, eh?

[BeerMe]

Since I decided around 2 months ago that my next step up from my 5" Heritage was a 10" Flextube, and started saving for it, I've been keeping an eye on the various sites for any bargains that come up, to help me get an idea of how much I need to raise to make that next step.

Since then, I've heard of 1 person who managed to get one second-hand  (not sure from where - must have missed the advert altogether) and that's been it.  I've seen 5s, 6s, an absolute raft of 8s, even several 12s and bigger but not a single 10" Dob for sale.  Uncanny...

Other than here, ASB and that auction site, is there anywhere else that these show up regularly?  I feel as if there is a secret cabal of 10" Dob users somewhere hidden on the Internet  

[jabeoo1]

http://ensoptical.co.uk/telescopes/-orion-skyquest-xt10i-

[jabeoo1]

I think they may be just a nice size: ie Big enough to be a light bucket, small enough to not cause a hernia.

[swamp thing]

As above. I believe the 10" Dob is the Goldilocks size.

 

[ronin]

I would go a bit the other way and say that they fall between 2 sizes and are not bought that often but also not sold when they are bought.

Everyone gets told and pointed at an 8" dobsonian, then for a step up in aperture it is generally said to get twice the area, that means a 12" (64:144 = 2.25x area) whereas a 10" gives (64:100 = 1.56x area). So I would suspect that people jump over a 10" to a 12" (or more), or they stay at 8" for convenience.

If a person buys a 10" then to get 2x area it means a 14" which is getting a bit big so they stay at 10" and they do not appear for sale.

 

[BeerMe]

15 minutes ago, jabeoo1 said:

http://ensoptical.co.uk/telescopes/-orion-skyquest-xt10i-

That's a great bargain, out of reach for me at the moment unfortunately but definitely worth it.   Did you find that through a search or were you already aware of that site/item? 

Thanks for posting the link though, it's given me some hope :-)

 

19 minutes ago, jabeoo1 said:

I think they may be just a nice size: ie Big enough to be a light bucket, small enough to not cause a hernia.

It's certainly popular, so much so that no one wants to sell theirs it seems!! ;-)

[BeerMe]

5 minutes ago, ronin said:

I would go a bit the other way and say that they fall between 2 sizes and are not bought that often but also not sold when they are bought.

Everyone gets told and pointed at an 8" dobsonian, then for a step up in aperture it is generally said to get twice the area, that means a 12" (64:144 = 2.25x area) whereas a 10" gives (64:100 = 1.56x area). So I would suspect that people jump over a 10" to a 12" (or more), or they stay at 8" for convenience.

If a person buys a 10" then to get 2x area it means a 14" which is getting a bit big so they stay at 10" and they do not appear for sale.

 

Yeah I think you more or less nailed it ronin - the 10" is a 'stopping point' telescope and will be the maximum convenient aperture for most that marries power with portability, especially the Flextube version. 

I live in hope...:-)

[CraigT82]

Keep an eye on the '2nd hand astro equipment' Facebook group too. Also astroboot get dobs in now and then. 

 

[BeerMe]

1 minute ago, CraigT82 said:

Keep an eye on the '2nd hand astro equipment' Facebook group too. Also astroboot get dobs in now and then. 

 

Thanks Craig, I am a member and look on it daily too.  Forgot to mention it ?

[jabeoo1]

8 minutes ago, BeerMe said:

 Did you find that through a search or were you already aware of that site/item? 

I check that site out quite a bit, he has only very decent used gear. 

[BeerMe]

6 minutes ago, jabeoo1 said:

I check that site out quite a bit, he has only very decent used gear. 

Thanks, added to my favourites! :-)

[Tim]

Hmm, when I wanted to get a dob for the garden and to use while my 18" is being fine tuned there was several available on the used sites. Not the flextube version zo much as the solid. Picked up a hardly used one for 200 notes.

Sadly with the skies we've had in the last 3 months since I got it, it is still hardly used..

[John]

I found a Skywatcher 10" dob on e.bay a few years back in mint condition for £100 !. I had to drive 150 miles round trip to get it but what a bargain !

If you can be patient something will come up. Trying a "wanted" advert on UK Astro Buy & Sell can produce good results. I suppose the way it works is that we agonise over making the decision and, once made, we want to action it as quickly as possible and then a sort of "sods law" kicks in and all the ones you let go while you were thinking, have gone

The good buys are always the ones where you deal with another private individual for me. I know of the folks who are selling used equipment commercially and believe me, they paid a LOT less for those items than they are now selling them for. Buy, hey, they have to make a living from it so there you go.

 

[BeerMe]

4 hours ago, Tim said:

Hmm, when I wanted to get a dob for the garden and to use while my 18" is being fine tuned there was several available on the used sites. Not the flextube version zo much as the solid. Picked up a hardly used one for 200 notes.

Sadly with the skies we've had in the last 3 months since I got it, it is still hardly used..

If it comes to it, I'll just go for the solid tube version Tim.  For storage and portability the Flextube would obviously be ideal but they are not without their own drawbacks and tend to be a bit more expensive.  I haven't seen any of the solid tube versions for sale either come to think of it, but if I do then maybe the temptation to have a few extra quid for accessories might just sway me ;-)

4 hours ago, John said:

I found a Skywatcher 10" dob on e.bay a few years back in mint condition for £100 !. I had to drive 150 miles round trip to get it but what a bargain !

If you can be patient something will come up. Trying a "wanted" advert on UK Astro Buy & Sell can produce good results. I suppose the way it works is that we agonise over making the decision and, once made, we want to action it as quickly as possible and then a sort of "sods law" kicks in and all the ones you let go while you were thinking, have gone

The good buys are always the ones where you deal with another private individual for me. I know of the folks who are selling used equipment commercially and believe me, they paid a LOT less for those items than they are now selling them for. Buy, hey, they have to make a living from it so there you go.

 

A 10" Dob for  £100?!  I'd drive the length of the country for a deal like that lol.

I did actually see a 12" yesterday on ASB for £225 which seemed an incredible bargain - it came up sold within 2 hours, unsurprisingly.  As you say there are definitely great deals to be had, and patience is key ;-)

[niallk]

13 hours ago, BeerMe said:

Yeah I think you more or less nailed it ronin - the 10" is a 'stopping point' telescope and will be the maximum convenient aperture for most that marries power with portability, especially the Flextube version. 

I live in hope...:-)

I found 10" to be a great starting point 

Best of luck sourcing one,

-Niall

[Stu]

Nice 10" Orion Optics on eBay at the moment.

https://www.ebay.co.uk/itm/262903194240 

[Paul73]

Nice scope. 1/8 optics will make all the difference. Rubbish focuser though.

I'd be tempted if I didn't have a serviceable 10" already.

IMHO this size is the best balance between convenience and aperture.

Paul

[JOC]

I read a thread like this and think 'Maybe I should have got the 10"', on the other hand I'd still be putting the same EP's into it............

[Charic]

I gave up on the idea due to the lack of second hand models and no telescope shops in Scotland? at least none this far North.
I wanted to compare aside the 8" to see if there was any improvement, under the same conditions. If there was, then I would have at first opted for a 12" as its slower, the 10" next, all just for visual, and all solid tubes! Even bought three Delos for the event, but the scope I have is staying, the Delos are going to good homes ( 8mm went on Monday) and I'm expecting to keep the 8" for much longer now, if not forever!..............who knows?

[BeerMe]

4 hours ago, Stu said:

Nice 10" Orion Optics on eBay at the moment.

https://www.ebay.co.uk/itm/262903194240 

 

4 hours ago, Paul73 said:

Nice scope. 1/8 optics will make all the difference. Rubbish focuser though.

I'd be tempted if I didn't have a serviceable 10" already.

IMHO this size is the best balance between convenience and aperture.

Paul

Seen it earlier but it's a fair bit above my price range for a solid tube 10" Dob, even with the great optics (which to be honest, are probably wasted on me).  I'm not at the buying stage right now - a fortnight or so and I'll have enough funds that I don't have to sell my Heritage to fund it.  I'll just be selling it to fund accessories for the 10" ;-)

 

3 hours ago, JOC said:

I read a thread like this and think 'Maybe I should have got the 10"', on the other hand I'd still be putting the same EP's into it............

On the one hand I can see your point JOC (I hinted earlier that having spare funds for EPs might sway me), and then I checked your list of optical aids and realised that we are speaking from a different perspective ;-)

Bear in mind too that I'm in the second-hand market...the price/aperture difference is much less significant.  

[JOC]

Hi Paul

5 hours ago, BeerMe said:

then I checked your list of optical aids and realised that we are speaking from a different perspective ;-)

IMO possibly not so much - whether anyone uses TV ethos - or some bog standard BST's - whether they spend £45 or £500 on their EP's within a certain telescope range all the EP's are all 5mm, 8mm. 10mm, 25mm etc.  As I understand things If you change from F6 to F4 or F7 within the same EP there will be a small amount of difference in apparent magnification, but as I understand things this visual difference won't be huge (I've played with some of the online models and this seems to be the case - it's an interesting thing to do).  Yes, the change in the mirror size is going to significantly affect the amount of light gathered, but as far as I see the biggest difference this makes is in the number of really distant grey wispy objects (these are GWO's - my version of specific types of DSOs) which it might be possible to see.  It continues to astound me that whatever pictures I see of huge telescopes it still boils down to viewing and getting apparently magnification through an eyepiece that still essentially looks like mine in a similar number of mm, OK the FOV is improved on expensive ones, but the size of the object viewed changes little IMO.  This was difficult for me accept when I first started using my telescope - as a non-owner I assumed that the bigger the scope the bigger the view of the object you saw - this was why I got the biggest I could.  As I understand things yes, someone might get more light from a 10" version of what I have, but IMO the same persons overall view on many objects wouldn't be hugely different to an 8"  - at least as I understand things.  Hence:

9 hours ago, JOC said:

'Maybe I should have got the 10"', on the other hand I'd still be putting the same EP's into it............

NB.  I hope I don't need a tin hat here!!

[John]

Most eyepieces perform pretty well in the central part of the field of view. It's in the outer parts where the differences show up especially as the focal ratio gets faster.

So often the initial reaction to moving from a lower cost to a premium eyepiece, of the same focal length, is that there is little or no discernable difference in performance. It's over time that differences start to show.

This is why my eyepiece reviews usually did not get posted until quite a few weeks or months had elapsed since I was provided with the eyepieces by FLO. I generally tried to have half a dozen sessions with them in various scopes and on various targets to be sure that I was noting differences between the eyepieces rather than other variable factors. And with the UK weather it takes time to get the scope time in !

 

[BeerMe]

1 hour ago, JOC said:

Hi Paul

IMO possibly not so much - whether anyone uses TV ethos - or some bog standard BST's - whether they spend £45 or £500 on their EP's within a certain telescope range all the EP's are all 5mm, 8mm. 10mm, 25mm etc.  As I understand things If you change from F6 to F4 or F7 within the same EP there will be a small amount of difference in apparent magnification, but as I understand things this visual difference won't be huge (I've played with some of the online models and this seems to be the case - it's an interesting thing to do).  Yes, the change in the mirror size is going to significantly affect the amount of light gathered, but as far as I see the biggest difference this makes is in the number of really distant grey wispy objects (these are GWO's - my version of specific types of DSOs) which it might be possible to see.  It continues to astound me that whatever pictures I see of huge telescopes it still boils down to viewing and getting apparently magnification through an eyepiece that still essentially looks like mine in a similar number of mm, OK the FOV is improved on expensive ones, but the size of the object viewed changes little IMO.  This was difficult for me accept when I first started using my telescope - as a non-owner I assumed that the bigger the scope the bigger the view of the object you saw - this was why I got the biggest I could.  As I understand things yes, someone might get more light from a 10" version of what I have, but IMO the same persons overall view on many objects wouldn't be hugely different to an 8"  - at least as I understand things.  Hence:

NB.  I hope I don't need a tin hat here!!

No tin hat required from my perspective JOC, all about opinions :-)

What I was trying to say was that, in the market in which I'm shopping, the price difference between an 8" and a 10" is not that great - at most it would be 2x Celestron X-Cel LX EPs which, whilst they are nice eyepieces, wouldn't convince me that a smaller aperture scope was worthwhile.  For yourself, however, the jump from an 8" to a 10" GOTO is fairly significant in monetary terms, therefore it makes more sense for you to go with the 8" and invest the rest in the fine set of optics that you've collected.

This may well be the last time I ever increase the aperture of a telescope, so I'd rather 'reach for the stars' and get as much as I can with my limited budget ;-)

[laudropb]

There is a 10 inch Dob just appeared on the classifieds here Paul.

[Paz]

I would try and be patient... Nothing will come up then 3 will come up at once.