opinions wanted about a short tube 80 or 90 mm

[Mukv]

Greetings

I am about to commit to buying a new grab / guider/finder scope from RVO http://www.rothervalleyoptics.co.uk/rvo-90mm-f500-achromat-refractor-ota.html . It will piggyback on my SW300pds mounted atop a NEQ6Pro weight of the new scope needs to be under 4kg which this is, before I commit to it I was wondering if anyone had other options and opinions on this size of scope? My budget is only £250 but could stretch a little if needed.

I use a canon 5dmk2 for DSO and a QHY132e for planetary photo, also an EQ3 Pro for grab and go kit later around xmas.

Andy

[NGC 1502]

Hi Andy, as I'm not an imager, can't comment on use as a guider.

For grab and go visual, would make a great wide field low to medium power low hassle scope.

Depending on your expectations, ok for higher power too, although higher powers (100x and up ) are not where short focus achromats are at their best.

I once had an Orion Shortube 90, and at low to medium power, particularly on deep sky, worked really well. It would split the double double easily at 125x, but the stars

were enveloped in a haze of light, didn't bother me too much, but would bother others perhaps.

For grab and go visual, a simple alt-az mount is all you need.

Hope others can help with the imaging part of your question, Ed.

[Mukv]

Greetings

The grab and go aspect is quite high in the equation and with the imaging ability a bonus, I hope to stay at less than 150X for visual so  the haze issue wont hinder viewing, what model scope did you have? curious about coatings on the glass.

Talking with RVO they say the glass is nicely corrected for both imaging and photog with quality coatings they are happy to recommend because it's one of their own specified designs ,

Thanks

Andy

[NGC 1502]

Greetings

The grab and go aspect is quite high in the equation and with the imaging ability a bonus, I hope to stay at less than 150X for visual so  the haze issue wont hinder viewing, what model scope did you have? curious about coatings on the glass.

Talking with RVO they say the glass is nicely corrected for both imaging and photog with quality coatings they are happy to recommend because it's one of their own specified designs ,

Thanks

Andy

Hi again Andy. My Shortube 90 was this one http://irwincur.tripod.com/orion_shortube_90.htm not made any longer, and the slightly larger version of the more popular ST80.

Don't know about the coatings, probably very standard ones.  Wish I hadn't sold it, great low hassle "bung it in the car just in case it's clear" scope 

I remember using it at my club, a sceptical clubmate was astounded by the pinpoint stars when viewing the double cluster at about 40x !

My main issue was that it had a 1.25" focuser, so it was hampered with very low power wide field use, just where it worked at its best.

The RVO scope sounds good......

Regards, Ed.

[John]

These short tube achromat refractors are great as portable "rich field" scopes for low to medium power observing of the deep sky but they show quite a lot of chromatic aberration on the moon and planets at high powers. I'd have thought that would make them less than ideal for planetary imaging ?

[Mukv]

Greetings

I use my SW305 PDS for imaging planetary, the short tube may well get used for DSO imaging but also guiding, planetary is just for observing as you point out the shortfalls for this type of tube.

The 500mm FL on a 90 tube is out of a choice of that or 800mm same 90mm tube a slightly wider field of view on the 500.

The orion short tubes have similar specs  also the ST80 that's why this topic not found a real alternative in my price bracket.

Andy

[Mark at Beaufort]

Andy I recently bought this little frac solely for grab and go whilst on holiday. I wanted something that I could carry onto an aircraft. To be honest its ok using a wide field eyepiece but after 60x it starts to get very soft. I previously had a William Optics SD66 which I now regret selling - you would not believe the difference.

http://www.opticstar.com/Run/Astronomy/Astro-Telescopes-Opticstar.asp?p=0_10_1_1_52

[StarryEyed]

An 80f5 is never a bad purchase and my last one was regarded so highly that it was never under mounted.

[ChrisLX200]

An 80f5 is never a bad purchase and my last one was regarded so highly that it was never under mounted.

LOL, should be nice and stable in a hurricane that...

ChrisH

[Fish]

I have a WO ZS66 SD great grab and go , guide scope and imaging. For observing everything about this little scope is spot on. They pop up on the second hand market quite often, may be worth having a look.

[Stu]

I would agree with that, the SD66 is a cracking little scope and would fulfill your needs nicely I should think. It will take around x130 ish, perhaps more under good conditions. I observed the GRS and shadow transits with mine, not easy necessarily but certainly doable.

Sent from my iPhone using Tapatalk

[Mukv]

Greetings

When I started this thread I was expecting a few to suggest SW st80's and the like but I'm amazed about the variety of gear used by you guys , some I never even considered. I was so certain I knew what I wanted but now I'm not so sure.. 

I'ts time to use this internet for what it was designed for no not PO*N, research into some of these new options for a grab and go kit. I never even considered second hand gear!!!

Andy

[carastro]

As you have a Skywatcher scope, do you have the 9 x 50 finderscope on it?   If so this can be converted to a finderguider with a small adapter.  However I am not sure about whether it will be suitable for a 300pds maybe the FL isn't good enough, but I am not very good with those sort of statistics.  Maybe some-one who is could comment, but if it is any good, then it will help with your weight issue, and also your pocket.

Carole 

[Mukv]

Greetings

Yes the 9X50 has been converted to a finder guider and one of my webcams live in it, the LifeCam studio the FL  is 350mm I  believe  I have used it for quite a while and I feel the need to replace it with something a little more versatile , I may even give it a go with the QHY for a night see what it performs like for a laugh..

Andy

[happy-kat]

My best view of Jupiter was using my orion ST80 much better than my 130p. Though I did not compare the two directly on the same night.

[lensman57]

Greetings

I am about to commit to buying a new grab / guider/finder scope from RVO http://www.rothervalleyoptics.co.uk/rvo-90mm-f500-achromat-refractor-ota.html . It will piggyback on my SW300pds mounted atop a NEQ6Pro weight of the new scope needs to be under 4kg which this is, before I commit to it I was wondering if anyone had other options and opinions on this size of scope? My budget is only £250 but could stretch a little if needed.

I use a canon 5dmk2 for DSO and a QHY132e for planetary photo, also an EQ3 Pro for grab and go kit later around xmas.

Andy

Hi Andy,

I had the Opticstar version of this scope, I bought it as my first widefield imager and it was hopeless at imaging as there was  just too much CA. As a low power visual it wasn't too bad on bright DSOs. I think that you are better off saving a little more and going for the WO ZS 71, Apo ED. I have one and it is a bargain at £369.00 from FLO.

Regards,

A.G

[Pig]

Andy,

I have the Equinox 80mm pro and it has turned out to be a top purchase, I would give it 10 out of 10.  The best views I have seen of Jupiter & Saturn are through this scope and the only CA I have witnessed is a very fine line when viewing a full moon.

[russ.will]

I was always quite surprized how good the views were through my ST80. It's somewhat 'budget' build did also give it the advantage of being very light which, given the weight you're already mounting, is handy.

Russell

[StarryEyed]

I agree with Russel good views and light weight.

I took mine to the canary islands one year amd was shocked at the clarity of the skies and then realised how good the little scope is. Price, contrasty, portable and versatile. There is no such thing as a bad one.

[John]

Personally I'd much rather have an ED80 over the ST80. The short achromats seem to have a fair amount of spherical aberration as well as the expected chromatic aberration. I've owned a couple of the ST80's and ST100's and I reckon some were not even diffraction limited. The ED80's I've had, on the other hand, were excellent, CA free and could be pushed beyond 50x per inch quite usefully when conditions were good. 

[Digger1895]

Sorry to be slightly off topic, just don't want to start a new thread for a simple noob question.

For AP why is an 80mm so popular? When you would think larger aperture would gather more light for AP. It can't be price when you look at the amount spent already on associated kit? It can't be size as scopes with larger aperture have similar length?

See, I it'll you it was a noob question :0(