What scope next?

kabuki777 (Yusuf) · #1 10-02-2016, 12:35 PM

I have an 8 inch dobsonian which I have had for about a month now. I live in suburbia and its not too badly lit up here just the clouds have been more present lately. I was looking at the next step down the road, should it be a 6 inch achromatic refractor , a c8 or a 14 inch dobsonian. Or maybe just get a 90mm refractor for a quick go sometimes as I dont have much time with kids and all. Its more for deep space viewing 90% of the time.

I have done hours of research and I like the sounds of the refractor big or small and maybe both, but if the 14 inch will go deeper then we shall go the way of the reflectors.

Another question is how big does a dobsonian have to be to start using a step or ladder to view because I cant see myself using a step, I just want mount and tube and DSO hunting. Cheers guys thanks.

The Mekon (John Briggs) · #2 10-02-2016, 01:18 PM

Quote:

Originally Posted by kabuki777

I have an 8 inch dobsonian which I have had for about a month now.
Another question is how big does a dobsonian have to be to start using a step or ladder to view because I cant see myself using a step, I just want mount and tube and DSO hunting. Cheers guys thanks.

1, You don't need another scope, you need to use the 8" you already have. What do you expect the 6" achro or 90mm will give you over the 8"? - nothing is the answer. How many DSO's have you seen with the 8"? - if you have knocked down most of the Messier objects and all the NGCs that are plotted in a sky atlas like Norton's or some of the other condensed atlases, then perhaps you are ready for a larger scope.

2. In the case of a 14" it would have to be F4 or faster, and you would need to be tall to do without any ladder or step at all. My dob is 80" focal length and all I need is a two step stool to see the zenith.

Bombardon (Eugene) · #3 10-02-2016, 01:38 PM

Yusuf,
You sky is not bad near Blacktown, certainly getting crisp at night when I visit grandkids in the nearby Ponds. John's thinking is sound. At least spend a year with your 8" and you will find it more and more useful as the sky settles for Autumn. Another advantage of running on your enthusiasm for a year is that you will settle into a pattern of viewing and be more clear on whether you want a general purpose scope, one for planets, doubles, deep sky. photography etc. Even Jupiter or Saturn could not have spent enough time in your 8"scope yet

The saddest thing I see on this site is people spending lots on big gear and within a short time desperately trying to recoup their losses from a hobby they don't have time for or have lost interest in. Keep that 8" warm

ZeroID (Brent) · #4 10-02-2016, 01:43 PM

John is quite right. A 10" or a 12" DOB would make some minor improvement on DSO's and still be manageable without a ladder but a refractor would not be an improvement for this target.
Seeing DSO's is a patient wait in a dark site, dark adaptation and using averted vision to discern the faint glow that reveals it. They do not show up with the kind of bright colours that Hubble leads you all to expect.
Your 8" is quite capable of seeing many DSO's but it takes practice. Most DSOs are only 'seen' at an amateur level by imaging.

kabuki777 (Yusuf) · #5 10-02-2016, 04:00 PM

Thank you for the replies, yes we newbies do get abit enthusiastic and are expecting to see really noticeable changes with the larger apertures. I got lucky and someone locally was selling the 8 inch gso for $250.

I will keep at it, thanks. Just with all those juicy big scopes out there its really tempting.

John you mentioned I wont be seeing any difference between the 8 dob and the 6 frac, is it really that close? Lucky I havent gone bigger because I was expecting a world of difference. Thanks again.

Chris.B (Christopher) · #6 10-02-2016, 04:29 PM

Your 8 inch dob is going to be way faster to set up than any refractor and will see more. Remember it is a light bucket the bigger the bucket the more you see. 90mm refractor will give faint cotton wool fuzzies the 8" will show details and structure. The best scope is the one you use. Head to a star party and take a look through all the scopes you can. You may be surprised how good the 8 stacks up. Must agree give it a full year, all 4 seasons and then think about upgrading.

Nab (Darren) · #7 10-02-2016, 04:51 PM

I've had my 8" Dob for about 3 and half years now and have come nowhere close to exhausting the possibilities of the scope. So I endorse the earlier comments. Use your 8" for longer and tease out its capabilities. Even on objects you revisit many times there is always more to see/find and learn about.

I have though, just decided to add a modest ED refractor to my scope stable - for two main reasons, 1. for use as a terrestrial camera lens, 2. to exploit short sessions (cloud, cold, time) that would not be available to a cooling 8" (which took nearly an hour to reach stable temp last night).

I have also begun to chase less glamorous objects such as carbon stars, doubles and open clusters. In fact I spent about 2 hours last night between Orion and Monoceros doing just that and thoroughly enjoying the viewing.

Cheers.

Darren.

barx1963 (Malcolm) · #8 10-02-2016, 05:58 PM

Quote:

Originally Posted by kabuki777

Thank you for the replies, yes we newbies do get abit enthusiastic and are expecting to see really noticeable changes with the larger apertures. I got lucky and someone locally was selling the 8 inch gso for $250.

I will keep at it, thanks. Just with all those juicy big scopes out there its really tempting.

John you mentioned I wont be seeing any difference between the 8 dob and the 6 frac, is it really that close? Lucky I havent gone bigger because I was expecting a world of difference. Thanks again.

I think you may be under the misapprehension that somehow optical quality like that seen in high end refractors, somehow compensates for smaller aperture. A 6" refractor is still a 6" and loses out to an 8" on simple ability to gather light. At the high end they do produce exceptional images, but for seeing DSOs, aperture makes a lot of difference.
I have been on the aperture path going from 6 months with a loan 8" dob to a 12" for 4 years and a 20" since 2012.. comparing the 8 to the 12 the difference is marked. Have also looked through a few 10" scopes and is a noticeable but not earth shattering difference.

Malcolm

The Mekon (John Briggs) · #9 10-02-2016, 07:20 PM

Yusuf,

Also look carefully at Nab (Darren)'s post and note the signature. He is using a very nice (I would say ideal) set of eyepieces to get the best out of his 8"
My brother-in-law has an 8" dob and could not believe the difference it made when I placed my 13mm T6 nagler in the focuser. A whole new scope just with one eyepiece.

kabuki777 (Yusuf) · #10 10-02-2016, 08:04 PM

Nice - so one can actually "do up" a telescope. I will do some research on eyepieces now but with the advice given I have only got my ankles wet on the beach as with the use of my 8 inch.
I want to actually now go to a star party and have a look at the quality of some scopes. Awesome.
Last night I was just sitting there with the tablet and an app open learning to map the sky so maybe thats another way to enjoy the night sky and that was without a telescope. Thanks again for the advice.

brian nordstrom (As avatar) · #11 10-02-2016, 11:47 PM

excellent remarks guys , this is why IIS is so good it's a special place for newbys , great help to new amature astronomers , this makes me so proud to be one .

Just a little clarifaction on the 8 inch Newtonion and 6 inch achromat refractor ,,,, Ok ,

These 2 scopes will show about the same detail and go as deep on deep sky objects , the refractor will show stars a little better ( as only a refractor can ) , the planets will be similar as will the moon , but the refractor will be sharper but will show a little CA ( purple ) around the brighter objects .

The Newt will require collumination regularley , the Frak wont ( unless dropped ) .

The Newt will need cleaning and covering properly , the frak is a sealed unit so is not bothered so much by dust and spiders .

The Newt is happy on a simple Dobsonion mount ,, the frak ??? needs at least an HEQ5-6 ,, HEAVY !!! expensive and BIG !!! .

Keep your 8 inch and do as has been said here , learn the sky , learn to observe and most of all ,,,, enjoy the learning curve , take you time ,, its awsome !

Brian.

Quote:

Originally Posted by kabuki777

Thank you for the replies, yes we newbies do get abit enthusiastic and are expecting to see really noticeable changes with the larger apertures. I got lucky and someone locally was selling the 8 inch gso for $250.

I will keep at it, thanks. Just with all those juicy big scopes out there its really tempting.

John you mentioned I wont be seeing any difference between the 8 dob and the 6 frac, is it really that close? Lucky I havent gone bigger because I was expecting a world of difference. Thanks again.

Mickoid (Michael) · #12 12-02-2016, 05:03 PM

Another thing to consider is posture. You may be climbing a ladder to view through a large dobsonian mounted scooe but you can be on your hands and knees viewing through a refractor. As I got older I got sick of getting down low to view objects high above with a refractor and bought myself a newtonian - ah, the relief!

doppler (Rick) · #13 12-02-2016, 07:40 PM

And if you can afford it why not both, 8" newt and 6" achro refractor. It only gets really expensive when you go to top shelf APO and Cass. scopes.

MattT · #14 12-02-2016, 08:24 PM

I think your missing out on the wide field views with an 8" f5? dob. At most 2.5º TFOV so if you must spend some csh go for a 4" f5 Achro Refractor and put it on a simple alt/az mount or as I have done on an EQ3.
A 4" on an EQ3 is perfection in my book....wide fields 5-6º TFOV depending on the eyepiece...tracking when you want. Out in the dark this set up is

tripl e thumbs up from me on all fronts....cheap....wide fields....portable...a great scope to add to a reflector.
Matt...who loves his f5 4" EQ3 Frac.

kabuki777 (Yusuf) · #15 13-02-2016, 10:13 AM

I was only out last night for an hour and my back is sore...I have a pinched nerve which plays up and I will not carry the Dobson mount and the tube together again, its not heavy but I know how the oldies feel now. Maybe a light weight telescope will be better but I will atleast be together a year with this 8 inch.
I will have to look through these wide field refractors before I buy one now as I am still in it for the DSO's. Its good the 4 inches on a mount are affordable and I live near Andrews and they give great advice too.
Right now thanks to the advice given in this thread I will be buying a mid power baader eyepiece from andrews and later the williams optics ultra wide or maybe the super wide eyepieces. Not expensive and they seem quality from the research I have done.