Dobs - Mass production optics vs premium optics

[vagk]

Has anyone done a side by side comparison between a mass production dob (such as Sky Watcher etc) vs a premium one (such as Hubble Optics, obsession etc) with same mirror aperture ?

Is it worth the much more cost regarding optical performance ? Differences are obvious at first glance ?

Thank you 

[Louis D]

The difference in optics mostly shows up at high power on low contrast objects like Jupiter.  Fine details like festoons become visible.

However, it's the attention to the mechanical details that makes custom Dobs so special.  The balance is right, the sticktion is right, the mirror cell is right, the secondary holder is right, the materials are long lasting, the focuser is a dream, DSC or goto integration is right, etc.  You don't have to spend your own valuable time trying to make it right, it just is from the start.

[Guest]

There is no doubt that the big premium scopes are better in almost every sense of the word.  I wish I had the budget to afford one.  That is honesty what it comes down to, can you afford one and the quality eyepieces to take full advantage of it.

[johninderby]

Premium brands certainly aren’t perfect and still cut corners on the mechanical side. Look at all the upgrade parts available for an Obsession dob to replace the stock parts with better quality ones.

Buiding your own custom dob appeals as you can use the best parts and get just the scope you want.

 

[niallk]

I can't answer your question directly - but I did compare a 10" SW 250px vs a 15" Classic Obsession on Jupiter.  It was a good night for seeing, but not excellent.  The 250px held up pretty well vs the Obsession that night, as I remember.  I think I binoviewed with the 250px, and mono with the Obsession.

That said, the 15" has simply given me my best ever views of Jupiter, Saturn, Mars etc on nights of unusually good seeing (and of course, it's way better on DSOs, which is what I got it for).  Better than I saw with years observing with my 250px. The question of whether going up in aperture is worth it would be an easier one for me to reply to! 😉

I think I was fortunate with my 250px in that it was a good example (in my limited experience!).  I've only bought one so I can't comment on chances of good or bad.  For planets the 250px has an advantage: cool down time, which is very important.   45mins for the 10" vs 2-3 hrs for the 15" (it has a 2" thick mirror).

From what I've read on forums, it sounds like the secondary mirror can often be worth upgrading in 'mass produced' scopes - and much cheaper to do too!  One can get pretty good primaries it would seem from what I read.  Of course one reads of poor examples.  When paying for a 'premium' mirror one pays to avoid that risk of a poor figure / poor polish (hopefully!!).

The Obsession moves beautifully leading to a very different experience at the EP.  The mechanics and well thought out no fuss ease of use makes a big difference, as @Louis D says.  But the 250px was the best money I spent on astronomy- no question.  You could spend as much on an EP as on a 250px.

There are certainly higher spec scopes than an Obsession - and one can easily double the price for similar aperture!  There seems to be no end to the 'upgrade' possibilities in this hobby like @johninderby mentions 😂

[johninderby]

Would love to build my own high end dob with no corners cut. 🙂

Now if Rowan would build components for a truss dob. Can you imagine what a dob built to Rowan engineering standards would be like. 🤔

[Merlin]

Most of us use our ‘scopes for stargazing rather than research. It seems to a case of overkill to have a premium grade ‘scope for casual viewing.

[AstroKeith]

1 hour ago, Merlin said:

Most of us use our ‘scopes for stargazing rather than research. It seems to a case of overkill to have a premium grade ‘scope for casual viewing.

I presume you watch a black and white television then?

For relaxation I watch television - a large 4K system with 7.1 sound. I have a premium tv system because I can see and hear the difference, not because I'm a professional tv watcher.

Same for my astronomy equipment, if I can see an improvement and I can afford it I will take it. Perhaps the key part is 'if I can afford it' which is always a value judgement (I could spend the cash on something else perhaps). Premium is only 'overkill' for someone who doesn't, can't or won't appreciate it.

Edited January 6, 2022 by AstroKeith

[John]

14 minutes ago, Merlin said:

Most of us use our ‘scopes for stargazing rather than research. It seems to a case of overkill to have a premium grade ‘scope for casual viewing.

That's an interesting viewpoint.

Judging by the enthusiasm on here for premium refractors, eyepieces etc, there are plenty of folks who want to get the very best that they can lay their hands on even if they are doing astronomy as a hobby.

 

[scotty38]

1 minute ago, AstroKeith said:

I presume you watch a black and white television then?

I'm pretty sure that's not what he's saying and speaking more of diminishing returns etc etc

[vagk]

And the next big question... Is it worth buying premium - high priced eyepieces (TeleVue etc) for common mass production telescopes ? Or it is waste of money and a medium priced eyepiece will have the same efficiency due to worse mirror ?

[AstroKeith]

6 minutes ago, vagk said:

And the next big question... Is it worth buying premium - high priced eyepieces (TeleVue etc) for common mass production telescopes ? Or it is waste of money and a medium priced eyepiece will have the same efficiency due to worse mirror ?

That is absolutely right. The performance of each component needs to match the rest and be balanced. This extends to the mount, the scopes collimation and one's eyesight.

Some of the mass produced mirrors are actually excellent (machine made), but they are so poorly mounted and then supplied with poor focusers and eyepieces.

With experience some of us are fortunate to be able to make judgements, but the beginner is in a  difficult position. 

[niallk]

1 hour ago, vagk said:

And the next big question... Is it worth buying premium - high priced eyepieces (TeleVue etc) for common mass production telescopes ? Or it is waste of money and a medium priced eyepiece will have the same efficiency due to worse mirror ?

I bought a plossl set from Telescope Service when I got my 250px, and it included a 15mm 'super wide' EP (70° afov) which was a favourite.

However: I eventually took the plunge on a TV N13T6- wow!  Way better to view through, and was gobsmacked to see colour in the Orion nebula with this EP: grey always in the cheaper EPs.  That EP set cost half the single 13mm, but the TV 13mm was by far way better value, and I got 2 more TV eps for that scope in due course.

I didn't buy any other EPs for the 250px, so can only comment on cheap vs TV, with the TV being highly recommended.

From what I read, there are "mid range cost" EPs available now which perform very well compared to TV, so several excellent value options out there nowadays for an f4.7 scope.  Others will be able to talk more authoratively than me!   My main recommendation is not to waste money on cheap sets.  Buy good quality, and buy once 😉

[Merlin]

My astro-equipment is pretty standard and it’s perfectly good enough for what I require for stargazing.

[Louis D]

13 hours ago, Merlin said:

Most of us use our ‘scopes for stargazing rather than research. It seems to a case of overkill to have a premium grade ‘scope for casual viewing.

A lot of folks who own premium scopes are far from casual with their observing.  Many choose to live in areas with very good seeing conditions, build roll-off observatories for their scopes, travel to multiple star parties each year, spend many days each year observing, spend entire nights observing and sleeping during the day, and are constantly searching out challenging objects.  For them, they want the best equipment to help them achieve their advanced observing goals.

[Captain Scarlet]

On 05/01/2022 at 22:03, johninderby said:

Would love to build my own high end dob with no corners cut. 🙂

Now if Rowan would build components for a truss dob. Can you imagine what a dob built to Rowan engineering standards would be like. 🤔

John we’ve all seen examples of your handiwork … you of all of us would be able to make a good dob I reckon? Why not?

[johninderby]

One day maybe if finances permit. 🤔

Edited January 7, 2022 by johninderby

[Guest]

I have had the opportunity to run my 10 inch Orion Skyline next to Teeter 20 inch.  I had my Orion eyepieces and he had his TV eyepieces.  Now there is no doubt that his 10k dollar scope performed better then my thousand dollar scope.  But the question is was it 9000 dollars worth of better?  For me, the answer is no.  We swapped around different eyepieces in both scopes and as expected the TV eyepieces were better in both scopes, but we're they so good that I would spend 700 bucks on a 31 Nagler to put in a 1000 dollar scope?  Not a chance.  What we all concluded high end eyepieces are at their best in higher end scopes.  My Orion eyepeices held their own and gave me roughly 90 percent of what the TVs showed at a price point that I can afford, and I am good with that.  In the end, it's to each their own.  

[Andrew_B]

On 06/01/2022 at 12:32, Merlin said:

Most of us use our ‘scopes for stargazing rather than research. It seems to a case of overkill to have a premium grade ‘scope for casual viewing.

Even top of the range amateur scopes aren't even close to the production standards or cost of the kind of high end optics used in research and defence applications. Have you ever heard of amateurs using silicon carbide mirrors or three/four mirror unobstructed anastigmat reflectors with optics that have been ion-beam polished?

Whether it's worth the investment in a Zambuto mirror over a mass-produced optic of similar aperture if you're just doing relatively low magnification DSO observing, I don't know.

 

1 hour ago, Mike Q said:

I have had the opportunity to run my 10 inch Orion Skyline next to Teeter 20 inch.  I had my Orion eyepieces and he had his TV eyepieces.  Now there is no doubt that his 10k dollar scope performed better then my thousand dollar scope.  But the question is was it 9000 dollars worth of better?  For me, the answer is no.  We swapped around different eyepieces in both scopes and as expected the TV eyepieces were better in both scopes, but we're they so good that I would spend 700 bucks on a 31 Nagler to put in a 1000 dollar scope?  Not a chance.  What we all concluded high end eyepieces are at their best in higher end scopes.  My Orion eyepeices held their own and gave me roughly 90 percent of what the TVs showed at a price point that I can afford, and I am good with that.  In the end, it's to each their own.  

What sort of things were you looking at and to what extent were you being limited by seeing? My understanding is that if you live somewhere like Florida then it's worth having a large Dob with a premium mirror because you'll have seeing good enough to view the planets at 800x magnification or higher, but in most other places you'll never get to push the limits like that.

Edited February 16, 2022 by Andrew_B

[jetstream]

2 hours ago, Mike Q said:

I have had the opportunity to run my 10 inch Orion Skyline next to Teeter 20 inch. 

Im curious what your targets were and how dark are the skies?

[jetstream]

50 minutes ago, Andrew_B said:

Whether it's worth the investment in a Zambuto mirror over a mass-produced optic of similar aperture if you're just doing relatively low magnification DSO observing, I don't know.

Depends on whether the mass produced optic is a " good one" - scatter (roughness) can be an issue in some. Many mass produced dobs benefit from stray light control -actually many high end structures do too. Controlling stray light in a dob is very high on my priority list.

But then, we pull out the Heritage 130 and observe so many DSO with this scope.... M33 a bright puff ball, M101, M51 The Flaming Star neb, California neb, Lagoon, Rossette, Barnards Loop and on and on.

I think this kind of points out the fact that dark skies are more important than the scope for DSO.IMHO.

[Stu]

On 06/01/2022 at 12:51, vagk said:

And the next big question... Is it worth buying premium - high priced eyepieces (TeleVue etc) for common mass production telescopes ? Or it is waste of money and a medium priced eyepiece will have the same efficiency due to worse mirror ?

Can’t necessarily answer that, but I do know that popping Televue eyepieces in a Heritage 150p is well worthwhile. The optics are of a very good standard and a decent eyepiece let’s you get the most out of them. If the Heritage was my only scope I wouldn’t buy Televues for it, but may as well use them as I have them anyway.

[Guest]

6 hours ago, jetstream said:

Im curious what your targets were and how dark are the skies?

Ohio is not known for having dark skies.  Even on the best of nights we are a 4.  We were set up in a terrible place with outdoor lighting on three sides and a busy road on the 4th.  As for targets, we just bounced around looking at whatever we could see.  

[Guest]

7 hours ago, Andrew_B said:

Even top of the range amateur scopes aren't even close to the production standards or cost of the kind of high end optics used in research and defence applications. Have you ever heard of amateurs using silicon carbide mirrors or three/four mirror unobstructed anastigmat reflectors with optics that have been ion-beam polished?

Whether it's worth the investment in a Zambuto mirror over a mass-produced optic of similar aperture if you're just doing relatively low magnification DSO observing, I don't know.

 

What sort of things were you looking at and to what extent were you being limited by seeing? My understanding is that if you live somewhere like Florida then it's worth having a large Dob with a premium mirror because you'll have seeing good enough to view the planets at 800x magnification or higher, but in most other places you'll never get to push the limits like that.

800x is a dream.  My skies in Ohio limit me to about 300x on the best of nights.  

[mikeDnight]

I think the gap between Premium and mass produced anything, be it refractors, reflectors or eyepieces,  has closed dramatically over the last 20years. A mass produced Dob with a top quality eyepiece will likely deliver better views than a premium Dob of the same aperture, that's using a mediocre eyepiece. The eyepiece after all is half the telescope. And there are many premium quality eyepieces to choose from, not just Televue.