Skywatcher Startravel 102 Refractor

[milkyjoe]

Yes, it's me again!

I've been given this some thought over the weekend and have come to the conclusion that I am going to do away with a GOTO scope because I've read they are not worth the cash on this size scope; I want to do the work myself as I feel I like gain more knowledge that way, and I can use the (free) Stellarium software if I want to find a particular object.

I have read a couple of reviews about this scope, and it seems like a winner, I realise this is a 'fast scope' and will be better suited to dso's rather than planets..., but I take it I will be able to see the planets in some form or another, whether I will be able to see much detail I do not know (perhaps someone can enlighten me?). I also realise this scope will suffer from a bit of CA on brighter objects, but I can buy a minus violet filter to combat this.

I was thinking about buying the 120 version of this scope, but apparently the 102 is much better. You can read the review here... Synta (Skywatcher) 120mm F/5 Achromatic Refractor - Review.

Does anyone own one of these scopes either on an eq1 or eq3-2 mount?

Any advice would be appreciated.

Richard.

[milkyjoe]

Just ordered this scope from FLO. Will report when it's received and I get a clear night to observe :-)

Can anyone recommend any decent ep's?

Thanks.

[Macavity]

I think the ST102 is one of those scopes that will always be useful. Eventually, even if you gravitate to bigger and better scopes, it will retain it's use as a WIDE field scope. It will be unique in showing the larger DSO like "Andromeda" and the Pleiades - the Moon will show good contrast and you can either filter or mentally "tune out" the false colour. In truth the Planets will show mostly the gross features - One (two) bands on Jupiter + satellites. Idem the rings of Saturn. It won't be too spectacular, but if you have good eyesight...

Of course (budget) fast scopes paradoxically require better (more expensive) eyepieces. But a decent uprated e.g. "Super Plossl" would give reasonable results. Ideally you might explore the wider fields with a mid-range wide-angle eyepiece. My Baader Hyperions work reasonably well but these days have "competition" among the newer (Skywatcher etc.) wide® field eyepieces... Others, with practical experience of these latter, might comment in more detail.

[Capricorn]

Scopes that are suite to DSO are (tend to be) fast.

For DSO's you need aperture. That is the primary requirement.

Fast is the ratio between focal length and aperture.

If you have a large aperture scope (best for DSO's) then in order to be able to look into the eyepiece it has to be fast.

If a 10" scope was say f/8 then it would have a focal length of 80", add say 12" for the height of the mirror off the ground then the focal plane would be 92" off the ground.

Even if you assume that the secondary shoves the path out to the side it will take out not much more then 9".

So the eyepiece ends up 83" off the ground, 6' 11".

You would have to stand on a box to look into it.

And if you stood on a box you cannot nudge a Dob in order to follow anything, you fall off the box.

So they have to make the focal length about 60" focal length so that people can use the things. So you get an f/5 or f/6 scope.

They are also made f/5 so that the scope assembly isn't an horrendous length.

Suggest you forget the term fast, it is used in photography. When we start putting an eyepiece in the path it wipes out using the term.

A scope of 150mm dia producing an image at 100x magnification should be the same immaterial of the f number of the instrument. Same light collection, same size image observed.

Two "problems" with fast scopes. You need good eyepieces - cost. To get magnification you need short focal length eyepieces which mean short eye relief which can be a pain.

[milkyjoe]

Thanks for your comments Macavity and Capricorn.

I've been reading so many reviews over the past month and been on so many different company websites, I think my eyeballs are broken!

My thoughts about the SW ST102 scope is that it will hopefully be a good all rounder. I need to start somewhere and I didn't just want to purchase any old scope only capable of viewing planets and not much else (although nice I'm sure that is). My requirements and budget prohibit me from buying something I might regret; I can always upgrade my scope in due time or buy something else with a bit more power if need be.

As I said, I have read a lot of reviews of different scopes, reflectors, refractors, sc's/mak's and I must say, there are too many to choose from! I was originally thinking of a nexstar 4se, small and compact although it is, I read mixed reviews (mostly good btw), but little comments people make tend to make you think twice, and it gets very annoying. lol

You mention needing short focal length ep's Capricorn, what sort of makes and sizes would you suggest to a beginner like me? I wear eye glasses so I guess I'm not going to be able to look at the stars with them on am I if they ep's I need have a short eye relief?!

I must say though I am very much looking forward to trying out my scope; I had one when I was a boy, but it was a very cheap one and suffice to say, it didn't get much use!

I will write a review when I get my scope.

[Moonshane]

I bought an Ethos yesterday off someone that has just this scope (as his holiday wide field scope). He loves it. He said with a good quality diagonal and TV plossls it's a wonderful scope with surprisingly little false colour / CA.

I can say it is very light and compact.

Personally, I'd prefer a larger dob (eg 8" f6 Skywatcher) which will be a better all round scope. That said, as others mentioned, there's a place for both and I bet eventually you'll have both.

ps

I am thinking of eventually getting one myself.

[TheThing]

First off, forget all the nonsense about a fast scope having to have expensive EPs. I've owned the SW ST 102 and it coped with a whole range of EPs. Othos work well with it (especailly the volcano tops like Circle T), as do Vixens, Tal Plossls and even the WO SWA's. You DO NOT have to spend hundreds of pounds on EPs to get good results with this scope.

Have a look round the sale board here when you get enough posts and also Astro Buy sell. You can pick up some cracking EPs and very decent prices 2nd hand.

The scope is very capable on DSOs and also the planets. There is no ideal scope for all, but as a beginner, you want notice any shortcomings with this scope until such time as you invet in another scope to directly compare it with. Colour fringing on even a bright moon is not really too evident or all that off putting. I used mine to view Jupiter, Saturn and Mars as well and with good results.

Enjoy and congrats on a great purchase.

[milkyjoe]

First off, forget all the nonsense about a fast scope having to have expensive EPs. I've owned the SW ST 102 and it coped with a whole range of EPs. Othos work well with it (especailly the volcano tops like Circle T), as do Vixens, Tal Plossls and even the WO SWA's. You DO NOT have to spend hundreds of pounds on EPs to get good results with this scope.

Have a look round the sale board here when you get enough posts and also Astro Buy sell. You can pick up some cracking EPs and very decent prices 2nd hand.

The scope is very capable on DSOs and also the planets. There is no ideal scope for all, but as a beginner, you want notice any shortcomings with this scope until such time as you invet in another scope to directly compare it with. Colour fringing on even a bright moon is not really too evident or all that off putting. I used mine to view Jupiter, Saturn and Mars as well and with good results.

Enjoy and congrats on a great purchase.

Thank you.

That's good to hear regarding the scope's capabilities, I was a little worried I'd made the wrong decision. The scope comes with a EQ1 mount, which I assume won't be that good?

I don't have enough posts to view the sale board at the moment.

I have purchased a Tal 2x barlow (recommended by another member), and a 7.5mm and 10mm SW Super Plossl from FLO. It should be interesting to compare these with the standard accessories shipped with the scope, which I've heard are not that good.

You say you looked at Saturn, Jupiter and Mars with this scope; what were the images like... detailed, crisp/blurry-much CA, large/small etc.?

Something else I am interested in is solar observing. I have seen you can buy Baader safety film, which I presume you just place over front of your scope, but a solar filter to put on the ep will also be required, yes?

Thanks for your help.

Richard.