Small Refractors

[Stu1smartcookie]

I am using a Celestron Omni XLT 127 at present , its a superb little scope .. but i want a widefield refractor ... i really dont want to pay too much and i am prepared to go down the route of an achromat rather than an Apo ,despite CA being an obvious pain . I like the idea of a small refractor just to stick on an alt-Az mount . To be honest its going to be used to view DSO's where possible rather than planets as the 127 does very well already . 

Any thoughts are welcome and its also nice to know what other people use . 

Stu 

[John]

I've had a few of the ST80 F/5 and ST102 F/5 achromats over the years and found that they do the sort of job you describe on a lightweight mount pretty well. The ST102 has a 2 inch focuser as standard so great if you really want to go wide with a 2 inch eyepiece.

 

[Space Hopper]

With my small grab and go, i didn't want to sacrifice aperture too much so opted for a 100mm class scope, rather than something in the 60-90mm range.

With a fairly small focal length, its easily manageable and opens up various mount options.

Through the binoviewer it will frame the entire M45 star cluster nicely to give you an example of it's wide field performance.

Here it is....

Edited November 2, 2020 by Space Hopper

[Alan64]

I landed this 80mm f/6 achromat(an ST80 is at f/5) several years ago...

I took that image whilst observing Comet 46P-Wirtenan about a couple of years ago, with a 2" 32mm 70° ocular and a 2" WO star-mirror diagonal.  The view was most spacious.  I watched the comet transit among the background stars long enough to verify that that was indeed the comet.  My own came with a 2" focusser.  However, an 80mm f/5 achromat, in all its models and under differing marques, comes with a 1.25" rather.

Synta offers a 102mm f/5 achromat under its Sky-Watcher branding, but a 102mm f/5 exhibits increased false-colour over an 80mm f/5.  A veritable kaleidoscope it would be, albeit when viewing brighter objects.

The one I feel that would be ideal is this one, a Meade "Infinity" 102mm f/6, and to compensate the aforementioned...

https://www.amazon.co.uk/Meade-Instruments-Infinity-Refractor-Telescope/dp/B00LY8JWAQ?th=1

But I'm not seeing it available there in the UK, let alone the latest Meade "StarPro" 102mm f/6.

Both are available across the "pond", from New York, yet are back-ordered...

https://www.bhphotovideo.com/c/product/1061426-REG/meade_209006_infinity_102mm_altazimuth_refractor.html

https://www.bhphotovideo.com/c/product/1438312-REG/meade_234004_starpro_az_102mm_f_6_5.html

I believe that the metal focussers of both are 2".  Both are also available from this vendor...

https://www.astroshop.eu/telescopes/meade-telescope-ac-102-660-starpro-az/p,59589

https://www.astroshop.eu/telescopes/meade-telescope-ac-102-600-infinity-az/p,51480

Edited November 2, 2020 by Alan64

[Stu1smartcookie]

Space , that looks a lovely scope .. i like the idea of 100mm or even a 120 as i think Skywatcher do a 120mm .. 

i looked at the bresser 102/460(again) as its supposed to have ED glass the last time i saw it  was when it was white ... now sold in a rather fetching black ... also the old fav 72ED from skywatcher which i have used before but i like the extra apperture that a 102 would bring 

Alan , yes a nice little scope indeed.. 

[vlaiv]

I had ST102 and while good, it is a bit crude - no retractable dew shield, focuser is rudimentary and overall scope feel is quite agricultural.

Recently I started looking for maybe another small and light weight wide field instrument and this one caught my eye (I probably not going to get it as I might go for ED glass but I do believe it is a bargain):

https://www.astroshop.eu/telescopes/omegon-telescope-90-500-ota/p,43767

Lighter than 100mm scope and more light grasp than 80mm one. Same focal length as 4" F/5 but being F/5.5 and only 90mm - probably less CA.

[Space Hopper]

6 minutes ago, Stu1smartcookie said:

Space , that looks a lovely scope .. i like the idea of 100mm or even a 120 as i think Skywatcher do a 120mm .. 

And they (SW) also do a 100mm as well.

The highly regarded Esprit 100 F5.5, so would give nice widefield views and be a great imaging scope.

Not cheap of course, but i'm sure there are second hand possibilities.

In the past i've owned a second hand WO FLT 98. Nice optics on that as well, but they are becoming a rare find on the used market.

[Stu1smartcookie]

the ST102 was one of my first scopes ... at the time i wasn't really into astronomy and i barely used it ... i wish i had it now ! the focuser is weak , are they interchangeable to a dual speed ?

I looked at an Omegon ...i saw a vlog on YouTube where a guy was using it with an AZ-Gti. 

[Joaquin69]

I own a sw startravel 120 achromat. CA is painful  in Bright objects. But nice on DSOs.  Its paired with a sw AZ5. Good, stable if you change the stock tripod

[gilesco]

2 minutes ago, Stu1smartcookie said:

the focuser is weak , are they interchangeable to a dual speed ?

Yes, the startravels can have the following focuser as a replacement: https://www.firstlightoptics.com/skywatcher-focusers/dual-speed-2-crayford-focuser-for-sky-watcher-refractors.html But whether you would invest in one that costs almost as much as the scope is another matter.

2 minutes ago, Joaquin69 said:

I own a sw startravel 120 achromat. CA is painful  in Bright objects. But nice on DSOs.  Its paired with a sw AZ5. Good, stable if you change the stock tripod

Me too, I am due to get an Esprit 120ED Pro, in which case, the StarTravel will probably be retired. I still think it has been a good scope, just frustrating focusing - I like my narrowband results, and they would improve if I continued to work on more exposures.

[Stu1smartcookie]

the st120 is something ( seems like ive thought about EVERY scope) i've also looked at ... and its relatively low cost too... i certainly would use it for DSO

[Mark at Beaufort]

Here is another option - http://www.opticstar.com/Run/Astronomy/Astro-Telescopes-Opticstar.asp?p=0_10_1_1_65

It looks a well built frac with a reasonable focuser. A 2" EP should give a 2.5 degree FOV (30mm/70 degree)

[vlaiv]

56 minutes ago, Stu1smartcookie said:

I looked at an Omegon ...i saw a vlog on YouTube where a guy was using it with an AZ-Gti. 

That Omegon that I linked was the same scope Opticstar used to have in their lineup - and it was even better as it had dual speed focuser.

For some reason they don't have it any more, but 90mm F/8.8 is certainly excellent scope for that money as well. I think one could mount it on AzGti as well.

[johninderby]

The Svbony SV48 90mm / 500 achro refractor perhaps? 👍🏻

https://www.ebay.co.uk/itm/SV48-2-Refractor-Astronomical-Telescope-OTA-Professional-indoor-Astrophotography/392976502175?hash=item5b7f398d9f:g:M2YAAOSwWHdfN4vE

Edited November 2, 2020 by johninderby

[Stu1smartcookie]

52 minutes ago, vlaiv said:

but 90mm F/8.8 is certainly excellent scope for that money as well. I think one could mount it on AzGti as well.

I am looking at this ... i will get a simple az-alt mount as i already have a cg4 

[Stu1smartcookie]

1 hour ago, johninderby said:

The Svbony SV48 90mm / 500 achro refractor perhaps? 👍🏻

Now that looks a really nice scope , John ... and a good price too ... i was hovering over the Bresser 102/460 but now i am  more interested in this ! It looks like its really well made ... love the DF on this model . 

Edited November 2, 2020 by Stu1smartcookie

[johninderby]

I used to have the Starsky 90 / 500 which was the same scope but in black. Good optics for an achro and lightweight. Build quality was so much better than the low cost Skywatcher scopes. Not as good as the higher priced scopes like the Altair etc. but OK.

[vlaiv]

7 minutes ago, Stu1smartcookie said:

Now that looks a really nice scope , John ... and a good price too ... i was hovering over the Bresser 103/460 but now i am  more interested in this ! It looks like its really well made ... love the DF on this model . 

I think it comes from the same factory as Omegon one. Only difference being dual speed focuser (Opticstar model had DF) and case - and of course, price difference reflects that.

 

[Stu1smartcookie]

1 minute ago, johninderby said:

I used to have the Starsky 90 / 500 which was the same scope but in black. Good optics for an achro and lightweight. Build quality was so much better than the low cost Skywatcher scopes. Not as good as the higher priced scopes like the Altair etc. but OK.

I think i am leaning towards this . I must admit i hate buying from that source but it really is a good price and is just what i am looking for .( more investigation tonight on the forum and on YouTube )

[johninderby]

Wish I hadn’t seen this thread now. Makes me think of getting one of the Svbony as a compact travel scope. 🤔

Noooooooo must resist. 😁

[johninderby]

It is Svbony’s eBay shop though. They also sell through Amazon but couldn’tfind the SV48.

Edited November 2, 2020 by johninderby

[rwilkey]

Hi Stu, I bought my wife the following for her birthday in March, it is very sturdy and perfect for both general and specialized viewing, the only caveat is that the pillar should not be used if you move the telescope around a lot (as my wife does inside/outside etc) - balance problems, if so. Here: https://www.firstlightoptics.com/sky-watcher-az5-deluxe/sky-watcher-startravel-102-az5-deluxe.html

[Stu1smartcookie]

1 minute ago, johninderby said:

It is Svbony’s eBay shop though. They also sell through Amazon but couldn’tfind the SV48.

Which is a bit more reassuring 

[Stu1smartcookie]

1 minute ago, rwilkey said:

Hi Stu, I bought my wife the following for her birthday in March, it is very sturdy and perfect for both general and specialized viewing, the only caveat is that the pillar should not be used if you move the telescope around a lot (as my wife does inside/outside etc) - balance problems, if so. Here: https://www.firstlightoptics.com/sky-watcher-az5-deluxe/sky-watcher-startravel-102-az5-deluxe.html

A good size scope of course , Robin ... Had a 102 , years ago and it never let me down .

[Alan64]

All entry-level focussers, whether of plastic or metal, whether a refractor or Newtonian, the parts are all there, except those that enable the draw-tube to rack in and out straight and true; with no wobbles or slop, yet easily and smooth as fresh-churned butter.  The factories are not going to provide that which can transform the focusser into a serviceable unit, and for decades...

https://stargazerslounge.com/topic/314294-the-synta-wonky-plastic-focusser-fix/

https://stargazerslounge.com/topic/323772-meade-polaris-90mm-f10-achromat/?do=findComment&comment=3528023

https://stargazerslounge.com/topic/323772-meade-polaris-90mm-f10-achromat/?do=findComment&comment=3528901

PTFE, or HDPE...

https://www.directplastics.co.uk/ptfe-sheet

https://www.directplastics.co.uk/hdpe-sheet