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Bresser Refractor Messier AR-102L/1350 - OTA

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#1 aa6ww

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Posted 19 April 2018 - 02:00 PM

I wonder if anyone has been exposed to this particular telescope.

 

https://www.teleskop...e-Assembly.html

 

 

Looks pretty fun for about $300. Its pretty light weight also. I wonder if anyone's looked through or used one of these before using the long focal ratio of F13.2.  It sounds pretty fun.

 

Even the focuser looks decent, though that rim on the front of t he dew shield looks kinda cheezy, but at the length this scope is, it probably makes sense.

Longer focal ratio then the current long tube AstroTelescopes 102mm Planet killer F 11 Telescope

 

their 90mm might even be a more practical scope since it would carry well on a lightweight GP type mount.

 

https://www.teleskop...e-Assembly.html

 

definitely needs a focuser upgrade though.

 

 

 

...Ralph


Edited by aa6ww, 19 April 2018 - 02:17 PM.


#2 Peter Besenbruch

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Posted 19 April 2018 - 04:54 PM

Yes, the 4" model has a vastly better focuser. They do say (in German) that a mount would make the scope [more] "practical" to use. It's not often you get a Sidgwick level, 4" achromat. Are you going to try one, Ralph?



#3 aa6ww

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Posted 19 April 2018 - 06:56 PM

I like the long tube refractors. I've done the Triplet and Fluorite refractor ownership thing but I just like the long tube achromat refractors. I  have classic F/15 and larger focal ratio scopes from the 60's and 70's in 60mm, 80mm and 102mm. But I see these and they are very inexpensive and I'm sure very fun to use.

I saw this topic come up about 2 years ago but it stopped abruptly without any information on what the results were.

 

I'm actually trying to thin out my scopes, I have too many of these classics. But these are different because they are modern versions.

 

Because of the size, I may consider the 90mm since it would fit on my Vixen mount without issues. The 102 may be too much for my smaller mount. 

 

Time will tell on this. Its always an option.

 

...Ralph



#4 Astrojensen

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Posted 21 April 2018 - 01:20 AM

The reviews on these are mixed, to say the least. Some samples appear to be okay or good, while others are basically unusable. The lens cell is plastic and this appears to be the source of some of the issues. 

 

 

Clear skies!
Thomas, Denmark


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#5 Ed D

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Posted 21 April 2018 - 07:31 AM

Hi Thomas,

 

The lens cell on my Explore Scientific AR102 is also plastic.  However, there are collimating screws in the front of the cell, as well as on the side of the cell to align the lenses axially.  Would you know if the Bresser cell is like this, or is it simply a low cost, non-adjustable cell like the lower end achromats?  BTW, the lens cell on the AR has never given me any trouble.

 

Ed D



#6 eros312

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Posted 21 April 2018 - 11:33 AM

The reviews on these are mixed, to say the least. Some samples appear to be okay or good, while others are basically unusable. The lens cell is plastic and this appears to be the source of some of the issues. 

 

 

Clear skies!
Thomas, Denmark

Hi Thomas. Do you have links to any of these reviews?



#7 Riccardo_italy

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Posted 21 April 2018 - 03:44 PM

It's a bit odd. A 4" f13.5 is not an entry level scope: it's a niche product bought by someone who strongly want it. I don't think 30€ more for a metal non-collimable lens cell would have discouraged perspective buyers.


Edited by Riccardo_italy, 21 April 2018 - 03:45 PM.

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#8 Astrojensen

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Posted 21 April 2018 - 04:16 PM

It's a bit odd. A 4" f13.5 is not an entry level scope: it's a niche product bought by someone who strongly want it. I don't think 30€ more for a metal non-collimable lens cell would have discouraged perspective buyers.

That's also the conclusion reached on the German forum astrotreff.de. 

 

 

Clear skies!
Thomas, Denmark



#9 Astrojensen

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Posted 21 April 2018 - 04:18 PM

Hi Thomas,

 

The lens cell on my Explore Scientific AR102 is also plastic.  However, there are collimating screws in the front of the cell, as well as on the side of the cell to align the lenses axially.  Would you know if the Bresser cell is like this, or is it simply a low cost, non-adjustable cell like the lower end achromats?  BTW, the lens cell on the AR has never given me any trouble.

 

Ed D

It is a plain, simple, non-adjustable, thin-walled, flexible plastic cell, like on the low end achromats. Sad. 

 

 

Clear skies!
Thomas, Denmark



#10 Astrojensen

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Posted 21 April 2018 - 04:22 PM

Hi Thomas. Do you have links to any of these reviews?

http://www.astrotref...TOPIC_ID=209314

 

http://www.astrotref...TOPIC_ID=220888

 

http://www.astrotref...TOPIC_ID=222286

 

 

Clear skies!
Thomas, Denmark


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#11 eros312

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Posted 23 April 2018 - 12:12 PM

Hmm. That's too bad. I might get the 102/1350 anyways because if it's trash, I have an Istar 100/1200 lens I bought a few years ago that could probably be adapted to the tube with a little surgery.


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#12 petmic

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Posted 23 April 2018 - 12:53 PM

It is a plain, simple, non-adjustable, thin-walled, flexible plastic cell, like on the low end achromats. Sad.


Clear skies!
Thomas, Denmark


Are other versions built in the same manner? I am intereste in AR 102s - 600mm focal length.

#13 Exnihilo

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Posted 23 April 2018 - 02:43 PM

Lens cell would be the deal breaker for me.


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#14 Astrojensen

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Posted 23 April 2018 - 03:13 PM

Lens cell would be the deal breaker for me.

Me too. When I read the horrifying reports, I just said "forget about this scope". And I was *really* interested in it, when I first heard about it. Seems Bresser shot themselves in the foot by skimping on the details. If they had made a good scope without any cringeworthy attempts to save a few bucks, and the first reports had been overwhelmingly positive, I think they could have sold a whole bunch of them, even if it had cost 100 euros more. The German amateurs seem to have come to the same conclusion. Lots of people have shown interest, but been turned off by the reports of the plastic lens cell. 

 

 

Clear skies!
Thomas, Denmark


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#15 memento

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Posted 23 April 2018 - 03:25 PM

I also read about the two long Bressers and found them initially very interesting. Actually even the basic focuser of the 90 might be okay ... if you only use lightweight 1 1/4" eyepieces for it (when doing the Moon and planets ...). But that lens cell really ruins the idea.

 

There's also a long report / thread about the ES/Bresser 102 / 1000 here on CN. Of course that one has a different f/l and another brand name, but actually it's from the same factory. Regarding the overall finish and lens cell design they are exactly the same:

 

https://www.cloudyni...hinese-imports/

 

 

If I were them, I'd omit the subpar accessories like that plastic finder and the crap eyepiece and diagonal and put that money into a proper lens cell instead. Thomas



#16 Peter Besenbruch

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Posted 23 April 2018 - 05:21 PM

I like this on the 4" from the second post:

 

Noch mal Schwenk auf Prokyon bei 135x : punktförmiges Fokusbild ist nicht möglich...im besten Fokus zeigt sich eine kleine Scheibe mit deutlicher CA ! Intrafokal zeigen sich fransige Beugungsringe....nicht wirklich schön...extrafokal wird's ganz schlimm : ein undefinierbarer grün-violetter matschiger Knödel.

 

Again swing to Procyon at 135x: point-like focus is not possible...at best focus it shows a disk with pronounced CA! Intrafocal shows fringed diffraction rings... not really nice...extrafocal gets real bad: an undefinable, green-violet, soggy dumpling.


Edited by Peter Besenbruch, 23 April 2018 - 05:23 PM.

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#17 AaronM

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Posted 20 September 2018 - 12:25 PM

Hello Peter, thanks for translating a part of my test-report in english. do you have german roots ? Peter Besenbruch its a pure german name, I guess ?

 

Kind regards, Michael

 

For me its very difficult to write long text in english without errors, but I have to say, that in the case of the Bresser 102/1350 Achromat a few very surprising things have happened......well, I have to say: for me and my friend Hannes Hase-Bergen it was clear from the beginning, that it is nearly impossible that a f/13 achromat could be so bad.

And meanwhile we found out.....the 102/1350 mm achromat has many potential and can give you very good views, but........

 

feel free to look here if you are able to read german text. The following links showing a great project what Hannes Hase-Bergen did with the Bresser 102/1350 - its fantastic !!! Maybe one can use google-translator....

 

Me myself have a similar plan, but also I had meanwhile an amazing adventure with the same Bresser 102/1350 achromat that I had first tested so bad - it is incredible!!waytogo.gif

 

Links to the famous project of my friend hannes Hase-Bergen ( in german ):

 

http://www.amateuras...21350/index.htm

 

http://www.amateuras...1350/index2.htm

 

http://www.amateuras...1350/index3.htm

 

 

And here my 2 reports of this refractor with an also surprising result bangbang.gif bow.gif pdf in german...sorry

 

The bad one :

 

http://www.amateuras...21350mmeier.pdf

 

The surprising one :

 

http://www.amateuras...1350mmeier2.pdf

 

Kind regards, Michael Aaron Meier from germany

 

 

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Edited by AaronM, 20 September 2018 - 01:24 PM.

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#18 AaronM

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Posted 23 September 2018 - 10:42 AM

..here  few pics with the Bresser 102/1350 mm but at poor seeingbawling.gif

 

 

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#19 db2005

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Posted 23 September 2018 - 12:32 PM

I had been eyeing out the AR102L too some time after they were introduced because I too wanted to experience "long-achromat" views. But the lacklustre reviews of the scope have kept me away, and it seems like I'm not the only one. But don't despair: if you really want a high-quality achromat there's still the Japan-made Vixen A105M - but be prepared to pay 3-4x more for it, and it's only f/9.5, not f/13.2.

 

The Vixen A105M has a major disadvantage: At a price-point significantly above the ED100 most people likely find it hard to justify not just getting the ED100 instead, with more bundled accessories and a decent carrying case ... all for less money. I did recently acquire the A105M's smaller sibling, the Japan-made A80M (80mm f/11.3), which is a very (!) nicely made achromat, and arguably one of the best achromats in current production. I'm currently in the process of comparing it with my (Chinese made) Vixen a80mf, and although I can't yet say anything conclusively about the optical quality differences, the mechanics are much better on the Japan-made scope.


Edited by db2005, 23 September 2018 - 12:32 PM.

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#20 AaronM

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Posted 30 September 2018 - 01:45 PM

a few more pics from today morning

 

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#21 hasebergen

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Posted 01 October 2018 - 02:14 AM

Good Morning,

also I own such a scope ... after delivering it was a catastrophe. So I couldn´t get a sharp view of Venus (magnification only 80x) because of coma ... f*ck! What could be the reason? The optics itself? But then I looked at the plastic lens cell and saw: this m u s t  be the cause of the horrible result.

So I started the project: "Improvement of the Bresser AR 102-L". In the focus: the lens cell. Together with another starfriend we created a new adjustable lenscell (made of alu) and mounted it in on the tube: The result: Now the AR 102-L is an excellent refractor (in relation to the price (~260€ new)). After this upgrade I could raise the magnification up to 270x and more ... there was only a little bit CA, sharp views without any coma ... great! I could visit Saturns complete Cassini-Division, details in Jupiters atmosphere, could split double stars "down" to 1"1 distance (HD 151070 Her // Dawes-limit!) and endless details on moon.

If you like to read some about this project (sorry - only in german): look at http://www.amateurastronomie.com - area "Projekte"

Now there´s a second project - to clarify the question a) are all Bresser AR102-L after derlivery afflicted with such problems as mine and - second -  whether it´s reasonable for greater quantity of these refractors to be upgraded and so improved with "our" new lens cell.  I´ll report resultes at the website :-) and also - my friend michel aaron told it - in the german forum "Astrotreff" (www.astrotreff.de)

And here some pics (without any image processing except detail magnification), taken with the AR 102-L, a 16mm Nagler type5 eyepiece and an Iphone - free hand ;-) 

Best regards Hannes

 

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#22 petmic

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Posted 01 October 2018 - 03:07 AM

Good Morning,

also I own such a scope ... after delivering it was a catastrophe. So I couldn´t get a sharp view of Venus (magnification only 80x) because of coma ... f*ck! What could be the reason? The optics itself? But then I looked at the plastic lens cell and saw: this m u s t  be the cause of the horrible result.

So I started the project: "Improvement of the Bresser AR 102-L". In the focus: the lens cell. Together with another starfriend we created a new adjustable lenscell (made of alu) and mounted it in on the tube: The result: Now the AR 102-L is an excellent refractor (in relation to the price (~260€ new)). After this upgrade I could raise the magnification up to 270x and more ... there was only a little bit CA, sharp views without any coma ... great! I could visit Saturns complete Cassini-Division, details in Jupiters atmosphere, could split double stars "down" to 1"1 distance (HD 151070 Her // Dawes-limit!) and endless details on moon.

If you like to read some about this project (sorry - only in german): look at http://www.amateurastronomie.com - area "Projekte"

Now there´s a second project - to clarify the question a) are all Bresser AR102-L after derlivery afflicted with such problems as mine and - second -  whether it´s reasonable for greater quantity of these refractors to be upgraded and so improved with "our" new lens cell.  I´ll report resultes at the website :-) and also - my friend michel aaron told it - in the german forum "Astrotreff" (www.astrotreff.de)

And here some pics (without any image processing except detail magnification), taken with the AR 102-L, a 16mm Nagler type5 eyepiece and an Iphone - free hand ;-) 

Best regards Hannes

Hi, that is an excellent job. I have a shorter version of that scope (AR102-S 600mm) and really love it. However, having a collimatable lens cell is a tempting idea. I am just wondering, would you be able to share the mechanical drawings for your aluminium lens cell? Thank you.



#23 hasebergen

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Posted 01 October 2018 - 06:26 AM

Hi Peter,

I wouldn´t have any problems to publish some mechanical drawings. But ... my partner, who has constructed the lens cell, made only some "little paintings" on a piece of paper. And I don´t know, whether he has chucked out these papers. He is a brillant mechanic, who made most of the lens cell out of his head.
But I´ll ask him, whether he has some drawings or he will permit to publish some photos of the lens cell. Problem: Now he´s on vacation and will return in the middle of October. But I´ll write him an email, maybe he´ll answer a little bit earlier.

Best regards Hannes


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#24 petmic

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Posted 01 October 2018 - 06:58 AM

Hi Peter,

I wouldn´t have any problems to publish some mechanical drawings. But ... my partner, who has constructed the lens cell, made only some "little paintings" on a piece of paper. And I don´t know, whether he has chucked out these papers. He is a brillant mechanic, who made most of the lens cell out of his head.
But I´ll ask him, whether he has some drawings or he will permit to publish some photos of the lens cell. Problem: Now he´s on vacation and will return in the middle of October. But I´ll write him an email, maybe he´ll answer a little bit earlier.

Best regards Hannes

Thank you. Even if they are sketches with only the most critical dimensions it would help. 



#25 AaronM

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Posted 03 October 2018 - 08:15 AM

Hello friends, I have posted an update of my experiences and tunings on the german astrotreff forum. If you like, you can maybe use google-translator perhaps ? kind regards, Michael Aaron

 

http://www.astrotref...TOPIC_ID=230397




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