Refractor purchase help

[Ashley Morgan]

Hey everyone, was wondering if I could get some advice from all you experienced and lovely folk here at SGL.

I have finaly decided (99% sure haha) that a refractor would be sensible first seriouse upgrade scope over my second hand helios 80mm refractor. I may be wrong as im still very much a begginer here but here is my reasoning behind it:

I mainly got into the habbit of lunar observing because of time constraints with my masters degree studies, so I was very limited to only short viewing times, but my course is over in 15 days so i can now dedicate whole nights to observing At my house light polution is visible but not so bad, the great thing is im only 15 minute drive away from a dark sky with very minimal light polution if any. But here is my dilema I got the bug for DSO hunting haha even on my small 80mm . Id like to point out im only a visual observer and do not intend to imaging untill im much older and have a much better bank balance haha. Now ive considered every scope with all the pros and cons of each many times and changed my mind like crazy over the past year as im sure some of you may remember haha but I think that a refractor would be best as the detail for lunar would be great but from what ive read also large refractors are also good for DSO viewing? correct me if im wrong? as I was totaly unaware that they could be used for DSO as i thought that newts and dobs were the only ones for dso's? so as I have a dark site I thought a good refractor would be able to suite both my purposes of lunar at home and DSO viewing for when i dedicate a night to the darksite once in a while... So would this actualy work???? could a good refractor (bigger the better im assuming) do both these things? if so could anyone suggest the best refractor for the job?

my budget is roughly £600 but i would also need a stand with it, size is not an issue or weight either so dont be worried about those factors Im not bothered by chromatic abberation and I believe from other posts this wouldnt be much of an issue with DSO's anyway? I know some may suggest newts or dobs but I also like the simplicity of no collimation etc just set up and go, as well as the more crisp viewing a refractor would give So if anyone could help, advise ammend me on any information I may have got wrong I would be very gratefull

Thanks in advance,

Ash

[Moonshane]

Refractors are great instruments and many like them for the reasons you state but I am one of the ones you predicted would recommend dobs.

As far as I am concerned there is no doubt that if you want to be a visual observer then only aperture will satisfy your wishes.

The problem with aperture is that unless you buy a dob/newt, you either have to buy a huge refractor and a mount to suit or accept that you'll get nice views of wider fields with less 'impact' or a larger SCT and again a heavy duty mount.

For your budget you could buy a used 10 or 12" dob which would provide excellent views of all objects. Collimation is easy so don't let this be an issue. Larger refractors sometimes need collimating and have adjustable cells for this purpose.

Just as an extreme example. Last night I was using a 16" dob and got the great views of some DSOs as you'd expect. I then put an aperture mask on to observe Jupiter as the seeing was OK but not great. This gave me an unobstructed APO like view at 170mm and f11. No diffraction spikes and wonderful almost photographic detail. This would be a large and expensive refractor. I also have a 6" f11 planetary dob and this gives excellent views too, comparable with the 16" with the aperture mask.

I am looking forward to a star party in Buxton in October as I really want to test the above set up against a good quality refractor to see whether or not I am fooling myself. I don't believe I am.

my best ever views of Saturn were with a full aperture 12" dob at about 230x magnification.

[valleyman]

I'm with Moonshine, got to be a Dob.

Where is your dark site in Wales?

[lw24]

If you could increase your budget by £95, you could get a Startravel 150 EQ5 - £695.

I understand why you want a refractor, not a reflector, as it was the same reason as me. As the famous saying goes, the best telescope is the one you'll use the most.

If you don't want to worry about collimation, then avoid it. I'm not saying Reflectors should be avoided, as obviously, greater aperture means better DSO visual viewing, but sometimes, compromises have to be made.

Clear Skies

Luke

[Ashley Morgan]

hey guys thanks for the reply's

moonshane: nice and yeah let me know how the comparison goes, i do like the idea of large dobs but I dont want too big a scope to a certain extent lol

Hey valley man Ive been meaning to get in touch to come along to one of youre gatherings as it would be cool to find like minded astropeeps in wales haha I dont go to a dark site perse but down the gower peninsula theres a long stretch of road over these hills and its pitch black there, according to google light pollution maps its also as clear as can be in wales theres also a car pull in area there so its perfect when nights are clear here.

The st 150 looks nice! how big is that in real life? I may look into that as I was considering the SW range of scopes. Have any of you used a refracter for purely DSO? as I would be keen to know what to realisticly expect from a frac for dso viewing

thanks again

[Bizibilder]

I would suggest coming "down" one to a SW 120mm refractor (Evostar). This is a really nice scope for the Sun, Moon and planets. Not too big or heavy and absolutely fine on an EQ3 or 5 size mount. A good Barlow and a couple of eyepieces will set you going. I would also suggest getting at least the motorised mount (not necessarily goto - just the dual axis motors) simply to make life simpler. As a visual observer this leaves your hands free for sketching etc. Some folk say these scopes suffer from chromatism, they do but I for one don't find it a problem except with very bright objects like Venus (You can get a filter that will almost eliminate this problem).

[MatthewC]

If dso's are your thing i would reconsider a dob mounted reflector. With your budget you could have a 10'' skyliner which would vastly outperform any of the refractors mentioned. I bought my 4'' refractor for most of the reasons you have stated but quickly discovered that although a cracking scope, it didn't have the light grasp to really make the dso's stand out. I bought the dob for this purpose a couple of months ago and my only regret was not getting the 10''

[Capricorn]

A scope is a scope, be it refractor or reflector, both can be pointed at planets, moon, stars, DSO and whatever else drifts into view.

Depending on the DSO's you want to look at and see you may need one that can gather a large amount of light. That is where reflectors have the edge. Equally I have seen a lot of DSO's using 8x42 binoculars

At this time is a post about seeing the super nova in M101 I think with binoculars. So how big is really necessary since the idea is find M101 in your binoculars then pick out the SN.

If you want a refractor then I suggest the Evostar range, they are achro's but longer so less CA. The Star Travels are convenient but being short the CA could be too much.

After that it really is how big a diameter. The bigger it is then the more light collected and the more that may be seem. Balance that against size and weight.

[JonnyP]

hey guys thanks for the reply's

I dont go to a dark site perse but down the gower peninsula theres a long stretch of road over these hills and its pitch black there, according to google light pollution maps its also as clear as can be in wales theres also a car pull in area there so its perfect when nights are clear here.

That would be up near Arthur's Stone on Cefn Bryn I'm guessing? Interesting - I've been trying to think of a dark sky site that's easy for me to get to. That's only a 20 minute drive.

My other thought was to head up towards the Lliw reservoirs. I can't think of any site with all round views as you'd get off Cefn Bryn, but I'm fairly sure it will be darker, although feeling a lot more remote..

You must be pretty close to me? I'm near Swansea city centre.

If you see someone lurking around in the dark up on Cefn Bryn, say hello!