Advice Please

[Geordiemac]

Hi

Bought a used Skywatcher Startravel 120 OTA and looking for advice on what eyepieces to buy.

Will be using the scope mainly for DSO 's

I would be very greatful if anyone who owns this scope could advise on what ep's they use and what they observe with them .

Hope someone can point me in the right direction as all this is still very new to me.

Regards

George

R

I hope my question makws sense as I am still very new to all this.

[John]

Hi George,

There are loads of options around for low and medium power eyepieces which will work well with your scope on deep sky objects. To a large extent the choice depends on how much you wish to spend with prices ranging from £50-£70 to £500+ per eyepiece.

Are you able / willing to use 2" format eyepieces ?. These show wider fields of view than their 1.25" counterparts so are a good choice for deep sky viewing.

[Geordiemac]

John the idea of buying a second hand OTA was to own something I can casually use when we go away in the caravan, I own a pair of bins I use when away as its a shame to miss the opportunity of the dark skies I find myself under when out in the countryside, the bins are ok but thought the scope would be a good alternative, as you can appreciate the Skywatcher 150 I have is alittle on the large side to use from a touring caravan, therefore the fact that I bought a fairly cheap small scope I, m not sure if it makes sense spending too much on the ep's.

Hope I am making sense here..... I enjoy using the 150 at home but don't want to miss out on some good viewing while away at weekends.

As far as 2" set up ? I am open to suggestions, as mentioned earlier I am still new to all this, was wondering if there is an all round suitable eyepiece I could buy which could be used with both scopes.

Cheers

George

[John]

....As far as 2" set up ? I am open to suggestions, as mentioned earlier I am still new to all this, was wondering if there is an all round suitable eyepiece I could buy which could be used with both scopes.

Cheers

George

Does your Explorer 150 accept 2" eyepieces ?

[ronin]

The scope is f/5, well usually the Startravels are.

Really go get a BST Starguider or 2.

They are good on f/5 scopes and not too expensive.

The scope will give some CA, and the scope is likely the limiting factor so a £300 eyepiece will not give much that the BST's won't.

For DSO's I suppose the 25mm and the 15mm or 18mm.

Part of the reason for these is any eyepiece that cost less will be plossl's and better then BST's will mean jumping to the £100+ per eyepiece bracket.

Personally I would leave the 2" options out of it.

[happy-kat]

When looking at the moon just remove the small centre cap on the cap it cuts CA totally away I find on my ST80.

As you already have a 150 telescope assume you already have eye prices why not use those.

[Geordiemac]

Thanks for all the advice, I guess I, m just wanting to get the best out of the scope on a budget since the scope is used.

Since I purchased the 150 I, ve always promised myself I would upgrade the ep's as reading the forum posts alot of people suggest the supplied ones are not the best.

There is also the fact that Fathers day is on the horizon and my daughters are gonna be looking into prezzies ;-)

Cheers

George

[John]

The ST120 is a low to medium power deep sky scope. It's not really designed for high power lunar and planetary observing because of the chromatic aberration (CA) that these fast achromat refractors generate. On the plus side though, CA has little or no effect on deep sky objects viewed at low to medium magnifications.

Staying with the 1.25" eyepiece format, a 30mm plossl eyepiece such as the Vixen NPL will show a true field of view of 2.5 degrees at 20x magnfication which is a reasonably large patch of sky. It would also work well with your 150PL newtonian and the cost is not too excessive at around £45.00. If you made that purchase and then added something like a BST Starguider at around £47.00 in, say,  the 12mm focal length that would give you 50x but still a wideish view. These two eyepieces would cover a lot of deep sky viewing, give you a noticeable improvement over the performance of the stock eyepieces, work in both your scopes (giving double the magnification and half the field of view in the 150PL) and cost a bit less than £100 in total.

[Geordiemac]

Thanks for that John, all advice on here is much appreciated.

I remember awhile ago we went down to a caravan park in Yorkshire and on the Friday night ....... wow the sky was fantastic, at home in the back garden I use the 150 but there is light pollution, this partcular night I had my bins with me and just thought " if only I had a scope" I could actually just make out the location of a couple of clusters with the naked eye and was amazed with the bins, unfortunately these cannot be held steady enough which is where the 120 comes in.

I cannot wait to use the scope on some true dark skies as I, ve never had that experience yet, and I, m sure on our caravan travels its just a matter of time.

George

[John]

I take my caravan to the SGL star party George - the past couple of years have been rather cloudy but we have had some superbly dark nights in the past 

Under really dark skies even relatively small aperture scopes show really good deep sky views - it's like almost doubling the aperture !