Cheap achro refractors

[neil phillips]

11 hours ago, badhex said:

Cheers Neil, yes it was a right state when I bought it - but thankfully it was very cheap! Focuser bolts sheared off in the tube, one of the lens cell lugs completely broken off, various bits missing and a large chip in the objective (thankfully only about 2-3mm into the aperture though). Honestly looked like it had been chucked down the stairs 😱

Manged to repair or replace almost everything but never managed to get it out for a first light. 

Funnily enough the white bresser Quasar at the top. i tested today. Straight away i could see there was a problem ( ok it cost me £39 including delivery ) But still that's a nice curry at my local takeaway lol. Tried it in the daytime it wasn't coming to focus properly. did a star test 10 mins ago, same problem. So, i thought what the heck might as well try and flip the front lens see if someone had taken it out to clean. and put it back in, back to front.

Lo and behold. they had. Just saw gas bands on Jupiter and 4 tiny pin prick moons. I might start a thread about it actually as the front lens had no rotation line on the side. to line up with the back lens. I think i read somewhere some of the real cheaper smaller ranges are not rotation aligned. basically just plonked together. Any idea about that do you know. 

Good luck with first light btw. Put a report up here when you do, i am sure others including me will find it interesting. 

[badhex]

Good work on the lens flip, I've heard of this happening before. For mine as I recall there was a pencil mark on both the objectives for rotation alignment, because it was a bit of a pain getting them to stay in the same rotation while I screwed the retaining ring back in. This might be specific to the Bresser Messiers vs the Quasar as the Messiers are a four element design (not quite Petzval but similar AFAIK). 

The original threads I posted are here if you are interested, they are over 8 years old 😱

 

[neil phillips]

52 minutes ago, badhex said:

Good work on the lens flip, I've heard of this happening before. For mine as I recall there was a pencil mark on both the objectives for rotation alignment, because it was a bit of a pain getting them to stay in the same rotation while I screwed the retaining ring back in. This might be specific to the Bresser Messiers vs the Quasar as the Messiers are a four element design (not quite Petzval but similar AFAIK). 

The original threads I posted are here if you are interested, they are over 8 years old 😱

 

sounds Interesting I will have a read, cheers for posting

[Ian McCallum]

On 14/10/2022 at 18:28, neil phillips said:

I know most might wonder what they think i am doing ? I Say don't underestimate cheap long focus refractors. 

Would you put the Sky-Watcher Evostar 120 achromat in the same category?🤔

[neil phillips]

12 minutes ago, Ian McCallum said:

Would you put the Sky-Watcher Evostar 120 achromat in the same category?🤔

Like all mass produced refractors scopes, they all vary. So each scope has to be evaluated on its own merit

[Gonariu]

On 14/10/2022 at 18:49, neil phillips said:

I seem to like buying cheap achromatic refractors. And imaging with them. Visual too sometimes. My latest I just got in excellent condition two days ago a Bresser Quasar 80mm/900  F11.3  cost £30 and £9 postage haven't imaged with it yet. Wonder how good the lens is ? will find out soon.

I think too that the little acromatics are good for price, portability and praticalness. This year I bought an vintage acromatic Bresser Optik 60/900 wich had a lot of accessories (five oculars whom two ortoscopic, stellar diagonal, staightening prism) and i paid it 100€. I tested it oberving the Moon wich I saw well a X225 too (with a ocular of 4 mm). But i like very much the Konus Vista-80, acromatic 80/400, whom CA does not disturb too much; I use it as telescope grab & go some for all and for observing panoramas. I paid the Vista 90€ two years ago.

[neil phillips]

4 hours ago, Gonariu said:

I think too that the little acromatics are good for price, portability and praticalness. This year I bought an vintage acromatic Bresser Optik 60/900 wich had a lot of accessories (five oculars whom two ortoscopic, stellar diagonal, staightening prism) and i paid it 100€. I tested it oberving the Moon wich I saw well a X225 too (with a ocular of 4 mm). But i like very much the Konus Vista-80, acromatic 80/400, whom CA does not disturb too much; I use it as telescope grab & go some for all and for observing panoramas. I paid the Vista 90€ two years ago.

Sounds like a lot of fun

[neil phillips]

Update Bresser Quasar that cost me £30 £9 delivery Someone had taken the front lens out and replaced it reversed. so of course i had to reverse that. There were no marks for orientation. So not possible, to do that. At these low end prices. not sure they are orientated anyway. Looking at jupiter didnt seem to be any problem. 4 tiny pin prick moons very tight. Did a star test at high power collimation looked perfect. nice concentric rings one side. very fuzzy the other. Classic under over correction problems that run through this type of low cost beginner instrument. Any way out observing the moon i took two captures and joined them 

 

 

 

Edited December 15, 2022 by neil phillips

[Moon-Monkey]

Ok so this must fall into this category my little 80mmF5 (ST80) while I own a variety of other instruments both fracs and newts there is something very enjoyable about grabbing the little ST and going out whether it’s visually observing the veil and rosette or doing some white light solar obs I’m going to start a thread at some point and detail all the work I’m doing to this little cheap achro and mount good thread here loads of great little and. Large scopes 👍👍

[windjammer]

Yes, a lot to be said for the achro doublets.  Cheap and cheerful but good fun - and capable imagers as well, but not OSC.  Here is my ST150 short tube F5 ...

Simon

[Coco]

Celestron SLT105  f/6.47/660mm  found on ebay 90 quid, its a real gem of a wide field scope, pin point stars to better than 90% through a cheap Starguider 12mm, using a range of SV Bony 1.25 filters ive had hours of fun. Yes false colour on the planets.

I'll order a decent focuser for it one day so I can use some heavier eyepieces, maybe I'll paint it or vinyl wrap it also   The optics really deserves to be in a better tube. Ive had fancy triplets (imaging days) that cost 25x more and for little gain visually.

 

 

[Moonlit Knight]

On 29/11/2022 at 08:54, Coco said:

Celestron SLT105  f/6.47/660mm  found on ebay 90 quid, its a real gem of a wide field scope, pin point stars to better than 90% through a cheap Starguider 12mm, using a range of SV Bony 1.25 filters ive had hours of fun. Yes false colour on the planets.

I'll order a decent focuser for it one day so I can use some heavier eyepieces, maybe I'll paint it or vinyl wrap it also   The optics really deserves to be in a better tube. Ive had fancy triplets (imaging days) that cost 25x more and for little gain visually.

 

 

I had one of those years ago. I thought, deep in my memory that they were fl7.5, but happy to be wrong. The optics are indeed very good for a short tube achromatic refractor. 

[Coco]

1 hour ago, Moonlit Knight said:

I had one of those years ago. I thought, deep in my memory that they were fl7.5, but happy to be wrong. The optics are indeed very good for a short tube achromatic refractor

Yours might have been but mine is not 😂 agreed the optics are indeed very good.

[RT65CB-SWL]

A few weeks, I got a ‘tip-off’ of a local house clearance as some of the content was astronomy related. 

Anyway... not sure if this is the right place, but to cut a long story short; it was an Aladdin’s cave of astro and photo-equipment. A few OTA’s caught my eye and one was a Meade 102mm/focal length about 900mm. My question is: how much is it worth? and should I get it?

I did not leave empty handed and I managed to find a cradle, albeit slightly oversize my ‘re-modded’ ETX105 for £5. The cradle is going to need some packing for a snug fit.

Edited December 6, 2022 by Philip R

[LDW1]

My NP101 is a lot of fun as well ! Great views.

[Coco]

3 hours ago, LDW1 said:

My NP101 is a lot of fun as well ! Great views.

Hardly a 'cheap achro refractor' or just a boastful type comment.

[LDW1]

21 hours ago, Coco said:

Hardly a 'cheap achro refractor' or just a boastful type comment.

Sorry, I misread the intent ! Not boastful as I really do enjoy the great views in my Svbony 48P, Vixen A62SS and my pre 1995 Celestron C80 refractors as much.

Edited December 7, 2022 by LDW1

[LDW1]

Just now, LDW1 said:

Sorry, I misread the intent ! Not boastful as I really do enjoy the great views in my Svbony 48P, Vixen A62SS and my 1995 Celestron C80 refractors as much.

At age 75 I don't have to boast any more !

[vlaiv]

Just ordered 80/600 achromatic pair from aliexpress .

I hope that if I plant it correctly and water it every day - it will grow into nice looking refractor by next year

 

[Peter Drew]

Just paint Takahashi on the tube and it will look enormous to some people.     🙂

[Rusted]

11 hours ago, Peter Drew said:

Just paint Takahashi on the tube and it will look enormous to some people.     🙂

Wouldn't that stunt its growth into a real refractor?

[neil phillips]

12 hours ago, vlaiv said:

Just ordered 80/600 achromatic pair from aliexpress .

I hope that if I plant it correctly and water it every day - it will grow into nice looking refractor by next year

 

Always wondered about the quality of the Ali lenses. good bad ugly ?

[vlaiv]

2 hours ago, neil phillips said:

Always wondered about the quality of the Ali lenses. good bad ugly ?

Have no idea, but I'll post my findings as soon as I get the chance to inspect them.

Given the holiday seasons, I expect them to arrive next year (at least 30 days shipping).

That will give me plenty of time to design and print focuser and order aluminum tubing locally (or maybe I should wait and measure lens themselves? Not sure, never designed a lens cell before).

[neil phillips]

39 minutes ago, vlaiv said:

Have no idea, but I'll post my findings as soon as I get the chance to inspect them.

Given the holiday seasons, I expect them to arrive next year (at least 30 days shipping).

That will give me plenty of time to design and print focuser and order aluminum tubing locally (or maybe I should wait and measure lens themselves? Not sure, never designed a lens cell before).

Its very interesting will be watching. The cell can be a very simple affair, it will work just fine. Can tell that from my cheap achros here

[Alan64]

I got this Meade S102, a 102mm f/5.9 achromat, last year...

It was a second, a return to a wholesale-club; the only issue, a small scratch on the OTA, and not all that noticeable...

I've used it once, during the day.  It makes for a great terrestrial spotter.

I removed the refractor from its old-fashioned, yoke-type mount.  The OTA had three mounting plates, two for the yoke, and one for the slow-motion control-rod.  All three were removed, the six threaded holes into the OTA filled with set-screws...

Tube-rings were very difficult to find.  I had to settle for these, although intended for 100mm refractors...

As of this posting, I'm waiting on a proper dovetail-bar for it.  Those are very difficult to source as well.  I will then turn the telescope towards the sky at night, before I blacken and flock the telescope throughout, also to render the draw-tube true, square and slop-free within its run.