Explore Scientific 16" dob

[dynasty99]

Thanks I did not know they were a european brand. I hope it comes on over, that scope has been floating on and off my "some day.." list for a little while now.

[dynasty99]

Thanks I did not know they were a european brand. I hope it comes on over, that scope has been floating on and off my "some day.." list for a little while now.

Or - scratch that - I guess they are American but test products overseas first!

[dunkCambs]

Just joined the Forum after reading this thread and considering possible purchase ES 16" DOB but discussion herein seems to have halted?  Any snags with the 'scope apart from those previously hinted at ? What concerns me is the term 'BK 7 like' as if glass is a BK 7 clone ?  Any issues with this type of glass? Has anyone used the 'scope regularly this year? If so any major problems ? 

Best wishes

dunk

[estwing]

Have you got your heart set on one?...if not abs would be my first call... Could save you a lot of money...

[dunkCambs]

Have you got your heart set on one?...if not abs would be my first call... Could save you a lot of money...

Started researching after reading Sky at Night mag June review … still researching … have not seen any listed on UK ABS but have not yet searched there.

dunk

[John]

These people seem to sell them in the UK:

http://www.365astronomy.com/Explore-Scientific-Dobsonians/

The only one I've seen reported on is Steve / Binocularsky's who is the chap who has posted in this thread. They don't seem to be available in the USA as yet so no reports on the USA forums.

[Scosmico]

Dunk I do own the 12" for a year now. If I knew at the time what I know now I would no have bought it. The quality is just not there. I hope they managed to improve the quality since may last year. I do enjoy it though as I have no funds to replace it. Pm me if you want to know more details about it.

[Highburymark]

Probably. ES seem to have a special pricing policy for UK dealers which is higher than other parts of the world

Doesn't everyone? And not just astronomy. I've often seen British made cars (that are £50,000 in Britain) are priced around 50,000 dollars in the US. Despite the extra cost of transporting them over there.

Apologies for going off topic.

[dunkCambs]

These people seem to sell them in the UK:

http://www.365astronomy.com/Explore-Scientific-Dobsonians/

The only one I've seen reported on is Steve / Binocularsky's who is the chap who has posted in this thread. They don't seem to be available in the USA as yet so no reports on the USA forums.

Thanks; I'm aware of which dealers sell them and have them in stock or can get one in a few days . Need to see an 'in depth' review … the Sky at Night magazine review is too short … And would welcome opinions ref the glass described as 'BK7 like ' … either it is BK7 or it isn't . 

dunk

[John]

BK7 is a glass type that is made by a number of manufacturers. It's not particularly expensive or exotic. I believe GSO use it for their mirrors so that means Revelation, Meade Lightbridges etc.

[BinocularSky]

If you want a finished scope that requires no work, then this is not the scope (or th eprice) for you. If you don't mind treating it as a kit-scope that can bear some improving, I think it's fine. Given what I know from fiddling with mine, if I was in the same position that I was when I got it, I'd do the same again.

Or - scratch that - I guess they are American but test products overseas first!

 Neither; they are Chinese.

 What concerns me is the term 'BK 7 like' as if glass is a BK 7 clone ?  Any issues with this type of glass? Has anyone used the 'scope regularly this year?

BK7 is just bog-standard borosilicate crown. It's a Schott designation. It's not low-expansion or anything, but tends to take a decent polish. You need to let the scope cool down for an hour or so if you're taking it outside from somewhere warm but, given that it takes about 30 minutes to set up and collimate, that's not too much of a hardship.

I haven't used mine as regularly as I could have - the big binos are jsut far too convenient.

The issue with a lot of the Chinese stuff is quality control, which makes it very difficult to make general comments. I'm happy enough with mine (I don't use it for high mag stuff on planets - that's not what I'm interested in -- but for low-mag wide-field & medium mag vies of DSOs it's better than "OK") ; I'll be happier when I can put it in an observatory so I don't have to reassemble it every time I use it.

[dunkCambs]

Thank you very much Steve for advising of your experience. I'm not so keen now to acquire the 'scope because of possible and alleged QA issues - and I'm still not convinced that the 'BK-like' glass is as good as regular BK glass. Whilst not ruling the 'scope out completely I'm thinking that would be better to consider other options. I've never been totally convinced ref Dob mounts' potential longevity - especially those made from 'board' rather than e.g. decent plywood. The fact that the ES 16" is made from aluminium would or should offer longevity - but given its reputation e.g. threads requiring attention before it could be assembled  (according to published review) it might not hold its value. 

Best wishes

dunk

[ronin]

and I'm still not convinced that the 'BK-like' glass is as good as regular BK glass.

Do not worry much about the glass, it doesn't matter as the glass is simply a material to cut/grind the right profile into.

What is needed is that the glass has a low number of bubbles/inclusions in it - preferably none. After that it does not even need to be clear.

Good old school custard would do if it retained the shape.

One question that comes to mind is who and why would anyone use perfectly good piece of BK glass, look up the specifications and most are simply a lump of plate glass, and the rest tend to be Pyrex (oven ware).

What used to happen was at the end of the day companies would empty out the mouton glass into moulds and make up big lumps of glass blanks for scopes. These were the waste at the end of the day, not a controlled production of BK or BK-like glass.

[Dronno]

Hi guys!

i'm the owner of the 16" scope you've been talking about here for a while.

Just a few tips about getting and having it.

I bought it from that the UK store in Worthing http://www.365astronomy.com. The guy who runs it, Zoltan, is quite a decent man and it was a pleasure to deal with him - highly recommend him to you. I know that there's a German dealer who ships this scope from Germany but still if you're in the UK contact the store I mentioned above.

first about the general quality - i'd say for its money and size&weight it's a good deal. There were some things I've changed and still planning to redo but all of them are minors modifications. Well i'll tell you the secret when we were out lately stargazing even 18"Obsession scope implied some handwork and wasn't even close to plug&play...

More than that here in Moscow there's a local tech laboratory that checks the quality of scopes' mirrors. Here's the results for mine (it's in Russian but if you scroll down you can see all the diagrams and strehl ratio in English). http://www.fidgor.narod.ru/Observers/Test/test_281.html (btw those results weren't cleared from coma, with that strehl ratio would've been well above 0.7 I assume). Follow the link and on the photos there you'll see the major fault of this scope and the way I corrected it (those plastic screw-nuts that hold trusses were replaced with metal ones).

all in all for observing deep sky objects it's perfect, for planets and photo not enough...

and if you compare the tech analysis's  of similar 16"scopes  from SW and LB (Meade) to this one's you will come to the conclusion that ES is not that bad at all...

check it out:

http://www.fidgor.narod.ru/Observers/Test/test_207.html

http://www.fidgor.narod.ru/Observers/Test/test_161.html

http://www.fidgor.narod.ru/Observers/Test/test_122.html

http://www.fidgor.narod.ru/Observers/Test/test_108.html

In general i'm pleased with that scope.  easily handled by one person (32kg all together), good mechanics while pointing it, no mirror's quality issues for DSO...

I also turned the default fans around so the air flows on the mirror and installed a big fan at the back to suck the air out of the box.

anyway should you have any particular questions - just ask)

[dunkCambs]

Hi guys!

i'm the owner of the 16" scope you've been talking about here for a while.

Just a few tips about getting and having it.

I bought it from that the UK store in Worthing http://www.365astronomy.com. The guy who runs it, Zoltan, is quite a decent man and it was a pleasure to deal with him - highly recommend him to you. I know that there's a German dealer who ships this scope from Germany but still if you're in the UK contact the store I mentioned above.

first about the general quality - i'd say for its money and size&weight it's a good deal. There were some things I've changed and still planning to redo but all of them are minors modifications. Well i'll tell you the secret when we were out lately stargazing even 18"Obsession scope implied some handwork and wasn't even close to plug&play...

In general i'm pleased with that scope.  easily handled by one person (32kg all together), good mechanics while pointing it, no mirror's quality issues for DSO...

I also turned the default fans around so the air flows on the mirror and installed a big fan at the back to suck the air out of the box.

anyway should you have any particular questions - just ask)

Thank you Dronno … Your opinion and links are very helpful .  Maybe I'm being swayed in favour of the 'scope ... again  I guess lots of 'scopes require tweaking to get the best from them .  Does TAL offer anything similar in Russia? How do TAL prices in Russia compare to e.g. SW et al?  Did you experience cooling problems before you added the third fan? Those plastic nuts do look 'so so' quality … 'spoil the ship for a halfpenny-worth of tar' … 

Cheers

dunk

[dunkCambs]

EDIT:  … but maybe those plastic nuts are to minimise damage if dropped onto the mirror?

dunk

[faulksy]

but if the uta colapses due to the week captive nuts, i think there will be more damage

[niallk]

Geez those results look a bit scary! (? -I'm no expert).

BTW what were the issues with the 18" Obsession?

Thanks for the very interesting post + links,

-Niall

[John]

Geez those results look a bit scary! (? -I'm no expert).

That was what I thought.

[niallk]

That was what I thought.

I've no idea what my 250px primary mirror + secondary 'spec' is - but it gives me great views and enjoyment, and I'm very very happy I bought it. An awful lot of people seem to say similar things...

[pdols]

I've had my ES 12" for about 6 weeks and had a few outings with it. I chose it as my first scope for its ability to be packed down and fit easily into a small car. All the other truss dobs in a similar price range seemed to slide into themselves, and so still took up too much space to be much use with only a Vauxhall Corsa to take me around.

I also liked the bare bones approach with accessories as it meant I wasn't just working with mediocre kit right off the bat, and had extra budget to focus on accessories I wanted. RE optics I can't really make an informed comparison to much other than my Meade 10x50 bins. From an ease of use point of view, I've found it easy enough to set up by myself. In the light it's 10 mins without too much rush, 15-20 in the dark.

The resistance with movement isn't quite perfect to my feel, but again being my first scope I can't compare to others to say what's reasonable to expect. It's mostly a bit resistant to small nudges so at higher mags for planets I found myself overshooting then over correcting a lot. I'm sure it's mostly down to technique, and the rest I expect can be tweaked with altering tension when I get a chance and have had a few more outings.

Collimation has proved very easy and convenient (even for a first timer) once I realised that one of the adjustment screws wasn't faulty it was just so far unscrewed that it was nowhere near contact for making adjustments.

All in all, I know it's early days but I'm pleased with my choice in scope. I don't expect it to be my last scope but didn't when I bought it. Given the restrictions I have in respect to size when packed down and budget it's fulfilled its brief for me. It's a scope I expect to upgrade from but so far it promises to be exactly what I need right now. It's not perfect but I wouldn't expect it to be, and I certainly have no buyer's remorse. I guess the reason I've put such a long-winded reply is just as a reminder that there are trade offs when you play with size and portability and price. You could get a better scope of you changed one of those variables, but for what this scope is I think it's a fair balance of the 3.

Sent from my iPhone using Tapatalk

[Dronno]

i'm glad that my post was a bit of  help for somebody

replying to some of your questions...

about mounting extra fan - yes it helped a lot, the cooling time reduced drastically, so you get sharp picture much earlier (i'd say like another 30 mins of good observing).

about issues with Obsession "18 - it had balancing problems, it was a bit shaky and unstable, it had weak cooling system so the pic wasn't clear right away and of course you're suppose to fight the dew on your own... and we couldn't see any difference while observing any DSO between it and my ES (the four-fold price difference seemed to be the only one).

about TAL - the do still produce them as far as I know... and with the current rise in FX rate they grew to be more competitive against Chinese scopes. But reading some feedbacks they appear to have some quality control gaps...

about dropping anything on the mirror - I use that packing thing the scope went with to cover the mirror. I mount the scope and then take it out.

But I have to warn you as we all learnt here in Russia. Buying Chinese origin scope you play in lottery... you might get a pretty decent mirror  or total rubbish...  I seemed to get lucky. no guaranty you will.

talking about other modification  I went a long way with heating system  - controller, secondary mirror and eyepiece heater. optical finder heater still to make.  

[russ.will]

I thought all of the test results were interesting, albeit there's less results for the ES than for the multiple SWs. The best SW was the best of the lot, with the ES second, but then the worst SW was also the worst of the lot by quite a margin. I suspect if you lined up three of each, the average result for each would be virtually interchangeable.

Clearly, one pays one's money and takes one's chances with these cheap Chinese Dobs in terms of optics, but no one seems to be complaining from among the massed ranks of owners under actual night sky conditions. I whined a lot about my SW, but it then delivered superb 300x views of Jupiter on one particular night just before I sold it. The ES delivered similarly impressive views on a couple of nights, was a lot easier to transport, but needed collimating more after each tear down/set-up. the ES had a MUCH nicer focuser, but it was set at a silly angle, etc, etc.

I suppose it just comes down to which package you fancy modifying the most, because I couldn't live with either in their out of the box state.

Russell

[BinocularSky]

Latest mod: making the secondary end of the trusses "captive bolt" - at present I am using sliced-in-half tap washers as captive washers; they have the unexpected effect of giving a really nice feel of increasing resistance as I tighten the bolts. This makes the trusses into a single assembly.  With the new T-bolts in the blocks on the secondary, this makes it a whole lot easier to assemble at the secondary end, at the cost of being slightly more fiddly at the primary end - next stop, try some QR cams on the primary end (Russ, did you ever do this?).

When doing this, I noticed that a lot of the bolts holding fittings to the truss tubes were beginning to loosen. It might be an idea to check yours if you have one of these.

Had a good session last night; a lot of it was just trying out different things and "tuning" the tracking platform; got lazy and didn't bother with the shroud; session was eventually curtailed by dew. Also, I got lazy and didn't bother to collimate: bad idea: very sensitive to miscollimation.

I continue to be impressed with how much scope you get for the price. Roll on, longer nights!

[Smodtactical]

I've read this whole thread and I am very tempted by this scope. I'm looking for something in the 16-18 inch range but don't want to shell out massive $$ for a UC obsession or skywatcher star gate. 

Any more impressions about this scope? Also any thoughts about this scope vs hubble optics UL 16 / UL 18.

 

Thanks.