How cheap dare I go? Any experience of these?....

[parallaxerr]

As some of you will know, I recently downscaled my astro gear to, well, nearly nothing! A lack of time and therefore use, saw a lot of expensive gear sat around gathering dust, so all the equipment has now moved on to new homes.

I did, however, leave myself with a little something, that being an ST80 on an Orion Tritech II tripod with a Mk4 Baader Zoom & a few filters, the epitome of simplicity. How ironic that I'm now finding a little more time to use this simple scope, probably due to the lack of setup time required. It's literally a pick the whole lot up in one hand affair and I have found this most enjoyable.

Anyway, I have my eye on a small upgrade, but have resisted so far because I desperately do not want to end up on the slippery slope again. I would like a touch more focal length than the 400mm and obviously more aperture is always a good thing. I have the following two scopes in mind an wondered if anyone has any experience of them in this guise or other - I think the same (I guess) Yuzhong Optical lenses have been used in many brands.

http://www.opticstar.com/Run/Astronomy/Astro-Telescopes-Opticstar.asp?p=0_10_1_1_54

https://www.omegon.eu/telescopes/omegon-telescope-90-500-ota/p,43767#tab_bar_1_select

Pros/Cons - The 80/600 offers me the additional focal length I'd like and the 90/500 a bit more FL, but also a bit more aperture. The 80mm has a dual speed focuser whereas the 90mm does not. A prime consideration here is weight, the Tritech II tripod is rated up to approx 6kg, but based on the ST80 experience I would not want to go there, sub 3kg I think is the max for the counterbalance.

Also, I know I could probably get a used ED80 in this price range, however I do not want one. Been there, done that, it's quite heavy for an 80mm and the temptation fo fit a Moonlite etc. would be too great. Nor am I bothered about ED optics in general, I do like Achros.

Would be interested in any first hand experience reports with these scopes and any other recommendations that fit the same criteria, must be a frac.

Cheers

[johninderby]

I’ve had the 80mm and both the short and long fl 90mm versions. Pretty decent optics for an achro and noticeably better than the ST80.  Build quality is also vastly better. Not up to the standards of a WO scope but reasonable. The dual speed focuser is usefull and comes with the f8.8 90m. The f8.8 isn’t as wide field but does have less CA. 

Can definately recoomend these scopes. They’re not perfect but CA isn’t a big problem. Yes it’s there but not that noticeable at lower magnifications. Focuser feels a bit light duty compared to the focusers that come on better scopes but work fine if you don’t put too much weight on them.

I only recently sold my 90mm f8.8 as I picked up a second hand ED scope at a good price.

[alacant]

Hi. I've an opticstar ar80 f5. It's very well made and has well corrected optics (example here). If that is anything to go by, the f7.5 should be even better but with not such a wide field of view. My recommendation would be your 80mm choice.

HTH

 

[parallaxerr]

2 minutes ago, johninderby said:

I’ve had the 80mm and both the short and long fl 90mm versions. Pretty decent optics for an achro and noticeably better than the ST80.  Build quality is also vastly better. Not up to the standards of a WO scope but reasonable. The dual speed focuser is usefull and comes with the f8.8 90m. The f8.8 isn’t as wide field but does have less CA. 

Can definately recoomend these scopes. They’re not perfect but CA isn’t a big problem. Yes it’s there but not that noticeable at lower magnifications. Focuser feels a bit light duty compared to the focusers that come on better scopes but work fine if you don’t put too much weight on them.

I only recently sold my 90mm f8.8 as I picked up a second hand ED scope at a good price.

Thanks John, good feedback on build quality, nice to hear. The focuser would only have to dael with a 1.25" diagonal and the lighter, Mk4 Baader Zoom, so hopefully it would be OK.

1 minute ago, alacant said:

Hi. I've an opticstar ar80 f5. It's very well made and has well corrected optics (example here). If that is anything to go by, the f7.5 should be even better but with not such a wide field of view. My recommendation would be your 80mm choice.

HTH

 

Hi Alacant, long time no speak. That's an impressive image for a fast achro, but I know how good you are at fringe killing! I could never match your processing when I was alt/az imaging!

I just noticed there's no finder shoe on the 90mm which I think may be the deal breaker. I'd been leaning toward the 80mm anyway, suspecting the slower optics would be better corrected.

[Charic]

26 minutes ago, parallaxerr said:

...........the epitome of simplicity. How ironic that I'm now finding a little more time to use this simple scope, probably due to the lack of setup time required. It's literally a pick the whole lot up in one hand affair and I have found this most enjoyable.

 

I'd like to try an ED80 myself (some day) but despite your desire to only own a Refractor, your description above is  pretty fitting for my Skyliner, though you'll need both hands. 

Just as long as I don't  find that "slippery slope" in my garden!!!!!!

[michael.h.f.wilkinson]

The only thing with lower set-up time than my APM 80mm F/6 on Mini-Giro mount is a pair of binoculars. The two scopes you mention are really quite different. The 90mm is more of a wide-field instrument, and the 80mm F/7.5 somewhat less so. Having said that, because the 80mm F/7.5 has a 2" focuser, rather than the 1.25" of the ST80, the F/7.5 scope will allow a larger FOV if equipped with 2" EPs. Something like an SW Aero 40mm (clone of the TMB Paragon I once had) would give about 4.4 deg FOV,  compared to a maximum 3.87 deg FOV at a 27mm field stop in your ST80 (with e.g. a 24mm MaxVision 68 deg EP). CA will be much better controlled at F/7.5. The 90mm has more aperture, of course, but will definitely show more CA at higher magnification

[CraigT82]

I used to own the Opticstar AR90s (90mm F5.5 - same as the Omegon version). It made for a great rich field scope.  Build quality was good but the scope weighed very little, less than 3kgs if I remember correctly.  I used to hold it up to my eye like a monocular with a 32mm panaview and just sweep up and down the milky way.  I'd doubt you need a finder on it as with a widefiled EP it gives a huge TFoV. Maybe just a rigel quickfinder would be sufficient?

[parallaxerr]

58 minutes ago, michael.h.f.wilkinson said:

The only thing with lower set-up time than my APM 80mm F/6 on Mini-Giro mount is a pair of binoculars. The two scopes you mention are really quite different. The 90mm is more of a wide-field instrument, and the 80mm F/7.5 somewhat less so. Having said that, because the 80mm F/7.5 has a 2" focuser, rather than the 1.25" of the ST80, the F/7.5 scope will allow a larger FOV if equipped with 2" EPs. Something like an SW Aero 40mm (clone of the TMB Paragon I once had) would give about 4.4 deg FOV,  compared to a maximum 3.87 deg FOV at a 27mm field stop in your ST80 (with e.g. a 24mm MaxVision 68 deg EP). CA will be much better controlled at F/7.5. The 90mm has more aperture, of course, but will definitely show more CA at higher magnification

 

50 minutes ago, CraigT82 said:

I used to own the Opticstar AR90s (90mm F5.5 - same as the Omegon version). It made for a great rich field scope.  Build quality was good but the scope weighed very little, less than 3kgs if I remember correctly.  I used to hold it up to my eye like a monocular with a 32mm panaview and just sweep up and down the milky way.  I'd doubt you need a finder on it as with a widefiled EP it gives a huge TFoV. Maybe just a rigel quickfinder would be sufficient?

I hadn't considered the two scopes as being "that" different, but different they are. Actually, rich field has not proven that successful from home due to LP giving a very wishy washy view, so I tend to conentrate more on smaller clusters where I can darken the background sky down with a bit of extra mag. Also, I wanted a little more mag for the moon, where CA would become an issue with the F5.5 (though CA really doesn't bother me, like some).

I think my mind is made up, it'll be the 80mm from Opticstar. If my mount was a bit sturdier I'd go for their 90mm F8.8, but I'm just not sure it would be that useable on the Tritech with the added weight and length.

[michael.h.f.wilkinson]

If you want to go to higher magnification and weight is an issue, maybe this little beast would be interesting:

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p1178_Vixen-VMC110L-Maksutov-Teleskop-mit-110mm-Oeffnung-und-ebenem-Bildfeld.html

The short, light OTA should work well on comparatively light mounts, and at 110mm aperture it gathers a lot more light. Bit more expensive, of course. I must say I am tempted to get one of these little scopes myself.

 

[parallaxerr]

1 minute ago, michael.h.f.wilkinson said:

If you want to go to higher magnification and weight is an issue, maybe this little beast would be interesting:

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p1178_Vixen-VMC110L-Maksutov-Teleskop-mit-110mm-Oeffnung-und-ebenem-Bildfeld.html

The short, light OTA should work well on comparatively light mounts, and at 110mm aperture it gathers a lot more light. Bit more expensive, of course. I must say I am tempted to get one of these little scopes myself.

 

Already have a 102/127 Mak in the back of my mind for when planet season arrives!

[johninderby]

Opticstar AR90S f8.8 on photo tripod.

[parallaxerr]

2 minutes ago, johninderby said:

Opticstar AR90S f8.8 on photo tripod.

OH stop it John!

How did you find it re: vibration etc?

That tripod looks a fir bit sturdier than the Tritech II I have.

[michael.h.f.wilkinson]

6 minutes ago, parallaxerr said:

Already have a 102/127 Mak in the back of my mind for when planet season arrives!

I think the Vixen has the 102 mak beaten, and the Vixen's open tube means much faster cool down and low weight compared to aperture (it is only marginally heavier than the smaller 102 maks). The 127 Mak is 1.5 times the weight of the VMC 110. The VMC is also faster (F/9.4), so provides a wider field than either the 102 or 127 maks

[rl]

Like CraigT82 I have the AR90S and echo his comments. It's a great widefield scope. I've used it as a finder on 12" and 14" newts, an application for which it excels. The metalwork is exceptional for the outlay.

But as my only scope? It's not brilliant on planets. I would suggest waiting and paying a bit more for a S/H ED80 for maybe £200-£250. This ticks both the planetry and Deep Sky boxes as well as most small scopes can, is just as light and portable and you are less likely to have outgrown it should the interest spark up again. It will generally outperform both the options you are considering. I'd take the extra optical quality over the 10mm aperture increase. 

Are you really that fixed on a refractor? Secondhand 6" Newts go for under a ton and the short f/5 ones don't weigh a lot. 

Just my 50p...

RL

[johninderby]

4 minutes ago, parallaxerr said:

OH stop it John!

How did you find it re: vibration etc?

That tripod looks a fir bit sturdier than the Tritech II I have.

No problem with vibration but then the Manfrotto 475 tripod will hold 12kg.

BTW this is the ED that repaced the Opticstar.

 

[parallaxerr]

3 minutes ago, johninderby said:

BTW this is the ED that repaced the Opticstar.

The one I pondered over too long, before you snatched it away ? It's very pretty!

[johninderby]

6 minutes ago, parallaxerr said:

The one I pondered over too long, before you snatched it away ? It's very pretty!

And very happy with it.  ?

And in an added twist to the tale I later sold the Opticstar to the same gentleman I bought the ED from and it has now been the basis of a PST mod and apparently working very well. 

[parallaxerr]

I started considering the 90mm F8.8, then thought a larger video tripod would be required, then this, then that......Oh look, I'm on that slippery slope again!

Ordered the Opticstar 80/600, all things considered I think it will offer what I want without breaking the bank and being nice and shiney new (as I prefer my gear).

So if anyone wants/needs a pristine ST80, there's one going up in the ads!

[johninderby]

It’s called “Paralysis  by analysis” when there’s too many options to consider but think you’ll be happy with the scope chosen.  ?

[wheresthetorch?]

On 10/12/2018 at 18:57, parallaxerr said:

Ordered the Opticstar 80/600,

Hi @parallaxerr  Has the telescope arrived yet? I'm interested in putting one of these on my AZ5 mount as a grab and go set up, and would be interested in your first impressions of it. 

[parallaxerr]

15 minutes ago, wheresthetorch? said:

Hi @parallaxerr  Has the telescope arrived yet? I'm interested in putting one of these on my AZ5 mount as a grab and go set up, and would be interested in your first impressions of it. 

It's due for delivery today, so I'll be sure to post first impressions later on. Hopefully get first light soon, however, the forecast is pretty cloudy.....obviously!

[wheresthetorch?]

Brilliant - thanks. Yes, looks like being clouded out here as well.  Luckily it's works Xmas do tonight so I would have missed the Geminids peak anyway! 

[parallaxerr]

Well, it's here. Due to the lack of info on this specific scope, I started a review thread here...