74 replies to this topic

[kkokkolis]

Hello

Has anyone experience with the new Explore Scientific Ultra Light Dobsonian 406mm or any of the smaller ones? 

It sounds interesting. The mirrors have the classic focal ratios but the rocker boxes, chassis and colimation are different than the Skywatcher Flextubes we have here. And they are also cheaper! Too good to be true? 

Thanks for any feedback. 

[havasman]

Apparently they are too good to even be real. I've not heard of a delivered production model yet and have tried to keep a look out. 

[Starman1]

Delivery is supposed to be "Fall 2014".

Remember, Fall ends Dec.21.

[Donsell]

I haven't seen a US review, but reviews in Canada and the UK seem to be pretty good.  

 

http://stargazerslou...ight-dobsonian/

[IVM]

ES UK has one in stock at the moment. DHL to US $250! This scope is even a bit lighter than mine, although the mirror box is bigger. Looks good!

[Starman1]

OMG! A right-side focuser!  I'm going to die of shock.

It needs a rear fan, but that's super easy to add.

Looking forward to seeing one in the field at a star party.

[rnc39560]

I've seen good reviews on them. That WAS what I wanted to buy, but went with a 16" LB instead because of the wait and I could do a lay-a-way type plan also with the Lightbridge. I make the last payment in November! I did read a couple issues that needed attention and modifications, but what factory dob doesn't. Overall its going to be a great scope IMHO from what I've read. 

[Pinbout]

 

OMG! A right-side focuser!  I'm going to die of shock.

 

 

and their trusses are adjusted to use their coma corrector...how much back focus are they?

Edited by Pinbout, 10 September 2014 - 01:52 PM.

[Starman1]

 

 

OMG! A right-side focuser!  I'm going to die of shock.

 

 

and their trusses are adjusted to use their coma corrector...how much back focus are they?

 

Last I heard, the HRCC requires 32mm more in-travel than an eyepiece that focuses with its shoulder at the focal plane.

I wouldn't give a thumbs down to a right side focuser, though.  It's where I prefer them.

But it's the only Chinese dob I've seen with the focuser on that side.

[Pinbout]

http://www.cloudynig...glass-or-pyrex/

 

see what Cary says about bk7 glass in the #6 post.

 

and if ES is using a knock off of bk7 how well will it be annealed at that?

[Astrojensen]

 

But it's the only Chinese dob I've seen with the focuser on that side.

The Meade Lightbridge can also easily be configured to have the focuser on the right side (where I also prefer it), by rotating the UTA. I've done this and it works flawlessly.

 

 

Clear skies!

Thomas, Denmark

[stevew]

In the spring, my local retailer had them listed as arriving in the summer. In the summer, they re-listed them as available in the fall.

Now they are no longer on their web site.

Any idea why they would be available in Europe but not North America?

 

Steve

[Starman1]

In the spring, my local retailer had them listed as arriving in the summer. In the summer, they re-listed them as available in the fall.

Now they are no longer on their web site.

Any idea why they would be available in Europe but not North America?

 

Steve

Test market: Europe.

Bugs worked out?  Hopefully.

Revised production samples arrive for testing imminently in US (or may already be here, per schedule)

Some changes may be made to production scopes if issues are found, then they're shipped.

I'd put money on late Spring arrival, in that case.  If the samples are perfect, then maybe near New Year's Day.

I hope.

[dr.who]

I would say that it's because Europe doesn't have a lot of high end Dob manufacturers and is thus more tolerant of less than perfection when it comes to a Dob. From memory these are meant to compete at a market space above the stock Orion, Meade, etc level of construction. 

 

I was very interested in these when I was deciding on a Dob for myself and hounded ES about them. From memory they do not want to release in the US Market anything less than a Dob that is on par with the quality of their refractors and Mak-Newt. These did not meet that criteria. They are good Dob's as evidenced by the word coming out of the EU but are not where they could be considered a premium Dob. The mirrors are good it's just the fit and finish that is lacking. 

 

There are some amazing things in the UC market space coming down the pipe from Skywatcher and I think (my personal opinion) that ES wants to also compete in that space. I have seen and used the new UC Skywatcher truss Dobs in person and they are brilliant. So ES wants to make sure they are at the level the SW is at  in my opinion. 

[Miliu]

FYI, they are also available in Japan since not long ago:

 

http://www.kyoei-osa...95078/list.html

 

They cost about the same as their equivalent non-GOTO Skywatcher.

 

And the 14'' GOTO Skywatcher is about the same price as the 16'' ES Dobsonian. I'm having serious issues deciding on one or the other one ... 

[dr.who]

Miliu-

 

if you are viewing from one of the major cities in Japan then the GOTO function of the Skywatcher will be very helpful and the jump from 14 to 16 isn't that big. 14 to 18 or 20 on the other hand is huge! if you are wanting ultra compact and somewhat ultra light then I would suggest the Obsession UC 15 or the Sumerian Alkaid.

 

The weight savings I got with my 15 make it just as labor intensive as setting up my old EdgeHD 11 and CGEM but with more aperture and actually less time involved. Plus everything fits very nicely and neatly in my Camry Hybrid trunk. By everything I mean the scope, EP case, folding table, drop cloth, food, drinks cooler, and misc items for a full night's observing then nap in the AM before heading home.

[Pinbout]

 

So ES wants to make sure they are at the level the SW is at  in my opinion.

 

they better get a very light mirror then. that skywatchers mirror is very light.

[swamp thing]

Miliu-

 

i if you are wanting ultra compact and somewhat ultra light then I would suggest the Obsession UC 15 or the Sumerian Alkaid.

 

 

I wouldn't suggest the alkaid. 

[Pinbout]

 

Miliu-

 

i if you are wanting ultra compact and somewhat ultra light then I would suggest the Obsession UC 15 or the Sumerian Alkaid.

 

 

I wouldn't suggest the alkaid. 

 

 

build it.

 

https://3dwarehouse....d3-25578481d2d0

[dr.who]

 

Miliu-

 

i if you are wanting ultra compact and somewhat ultra light then I would suggest the Obsession UC 15 or the Sumerian Alkaid.

 

 

I wouldn't suggest the alkaid. 

 

 

Would you mind expanding your thoughts on this? I am curious why you dislike it. It was at the top of my list when I was looking around at large Dobs...

[dr.who]

 

 

Miliu-

 

i if you are wanting ultra compact and somewhat ultra light then I would suggest the Obsession UC 15 or the Sumerian Alkaid.

 

 

I wouldn't suggest the alkaid. 

 

 

build it.

 

https://3dwarehouse....d3-25578481d2d0

 

 

As you know Pinbot I love your design but I was saying that with the presumption that the OP didn't want to DIY it.

[Pinbout]

 

 

Miliu-

 

i if you are wanting ultra compact and somewhat ultra light then I would suggest the Obsession UC 15 or the Sumerian Alkaid.

 

 

I wouldn't suggest the alkaid. 

 

 

Would you mind expanding your thoughts on this? I am curious why you dislike it. It was at the top of my list when I was looking around at large Dobs...

 

 

 

I had some emails with him and at the time he wasn't selling to the states and was a little snarky about it also.

[Miliu]

Miliu-

 

if you are viewing from one of the major cities in Japan then the GOTO function of the Skywatcher will be very helpful and the jump from 14 to 16 isn't that big. 14 to 18 or 20 on the other hand is huge! if you are wanting ultra compact and somewhat ultra light then I would suggest the Obsession UC 15 or the Sumerian Alkaid.

 

The weight savings I got with my 15 make it just as labor intensive as setting up my old EdgeHD 11 and CGEM but with more aperture and actually less time involved. Plus everything fits very nicely and neatly in my Camry Hybrid trunk. By everything I mean the scope, EP case, folding table, drop cloth, food, drinks cooler, and misc items for a full night's observing then nap in the AM before heading home.

 

Thanks for the suggestion Dr. Who.

 

Both the Obsession and the Alkaid, although look like a good investment, are over the budget I got from my boss (the wife). Skywatcher and Explore Scientific are more reasonable options so that is what I’m considering at the moment. I'm also waiting for the SW 18’’ news.

 

From my point of view, even though the Skywatcher 14’’ GOTO is more bulky than the ES 16’’, it would fit well in my car (mount in the trunk and collapsed OTA standing on a back seat). I already have a SW 8’’ GOTO and that’s how I transport it every time I go out. Setup time of the SW should be also faster than the ES. On the other hand the ES is more compact so I may be able to bring it when going camping with the family.

 

Going back to the topic, I read somewhere that the fans on the ES Dobsonian suck air instead of blowing to the mirror. The poster then fixed it and reversed the airflow. Is that how it should be? I’m thinking that if the fans blow parallel to the surface of the mirror then there should an exhaust hole/fan on the other side of the mirror box.

 

Miliu

[Starman1]

Miliu,

It depends.

If the purpose is to break up the boundary layer and cool the mirror, the fans needn't have an exit on the other side.

In that case, they'd be turned off when observing starts.

If the fans run slower, and during observing, then an exit for the air on the other side is essential.

[Miliu]

Don,

 

So, for the ES Dob, what would it be best: using the fans to suck air or to blow air? If they are used to suck air, will they break the boundary layer properly and can they be used while observing? If they are used to blow air and they need to be off while observing, wouldn't a boundary layer start building up again as the ambient temperature drops?

 

Miliu