help deciding - Page 2

creeksky (Pete) · #21 03-01-2015, 12:06 PM

Quote:

Originally Posted by madwayne

Hi Pete

How far away is your nearest astronomy club or society? Before you spend your hard earned I suggest a visit to a club and talk to the members and look through their equipment. I couldn't think of a single one of us who wouldn't welcome anyone with an interest to look through their equipment.

If it's a bit of a hike could you visit family or friends while you are there to make the trip worth your effort and expense?

It's not about the colour, I'll image if I want colour. It's about being out under the skies and seeing what detail you can see.

If however you want colour, try observing carbon stars. In my opinion some of the prettiest things you will see in a telescope. My favourite so far is one near Mimosa in Crux, very deep red.

Hope my two bobs worth is of help to you and good luck on your journey.

Wayne

Hi, thanks Wayne,
I believe Brisbane would be the closest 2 hr 45 mins drive, though going through the forums there could be some folks that meet at North Casino NSW (50 ks) from me.
At present I'm still stuck near Wyong nsw. The pony club meets would only be 20 or so ks.
But joined up here after their last meet, perhaps I could time another visit down here to coincide with their next meet up, but I'm bitten by the bug already, and by Jan 12 will have enough funds for a decent second hand or maybe new 8 "inch Dob.
Though maybe its best to get a heritage P130 , to start?

Hoges (John) · #22 03-01-2015, 12:12 PM

For the difference of a few hundred bucks, I think the 8" Dob will give you the most bang for your buck. And the dob mount is the simplest mount to move around too. And, if you later decide you don't wan't to keep it, the 8" dob will probably be the easiest to sell. Or you could later get an EQ mount, put the 8" reflector on it and do some imaging....

But if you can get a look through some scopes in the meantime and chat with their owners, better still.

knightrider · #23 03-01-2015, 01:25 PM

Quote:

Originally Posted by creeksky

Feeling pretty shattered.
At home on a clear night I could swear with naked eye I can see some coloured stars orange, yellow, blue and maybe green too? But perhaps this is a trick of light like a rainbow.

The stars you see through the scope are indeed colourful just as you see them with your eye

There are also appears to be jagged swathes of pure black(no visible even faint stars) between what seems to be the spiral arms of our galaxy?Yes that's correct, it's the dark dust that blocks some of the light from the centre of our galaxy
The night sky explodes with millions more stars than I ever saw growing up in a city!
Lying back on a reclining chair looking up it appears a like a huge star studded massive dome!
While I didn't expect a telescope to show hubble size coloured nebulae, I kinda hoped mini versions, and differing star colours, Mars to be red or a dark orange with whitish polar caps, Jupiter with bands of some colour maybe a faint red spot, neptune a blue dot and maybe with luck Andromeda with a flash of yellow at its core?

The planets most definitely show colour through the telescope. Jupiter has coloured bands. Saturn has a beige hue. Mars is red, and with the right closeness to it and conditions you can see the white polar cap and the dark maria on the surface.
Neptune is blue. Uranus is teal/jade green. Venus is a bright stark white.

I understand now how limited our eyes are and I do understand how mind boggling far away the stars and DSOs are.
But they are all going to be like the monochrome moon? Faint hardly dicernable "fuzzies"
Or will with a faily decent scope my brain "imagine"and create colours? A lot of DSO's will be grey looking, however I have seen in the Orion a green hue. Quite a few plantetary nebula show a colour also.

Or atmophereic spectral refractions make them turn coloured or not at all?
I remember as a kid the wonder and joy of seeing jupiter a large pea sized round white ball and saturn white too with ears, at least (even with a toy Tasco refractor) seeing them with my own eyes was fantastic!
But even back in the 70s in Sydneys western burbs, light polution was bad.
Not until my first trip to Macksville in 1979 did I see the true night sky-just Wow!
Now I have it most every clear and moonless nights.
Just thought a scope would rekindle that "wonder".
-with colour and a bit more detail...

...

raymo · #24 03-01-2015, 09:52 PM

NGC 3918 is bright green in almost any scope.
raymo

creeksky (Pete) · #25 06-01-2015, 06:14 PM

Quote:

Originally Posted by raymo

NGC 3918 is bright green in almost any scope.
raymo

Well I missed out on an 8 inch Dob, So perhaps best to go with a skywatcher 130p?
I haven't yet (apart from planets)even 10 inch, seen any colour in DSOs unless filmed with a camera and registax post process.
Seems the universe is all black and white and unless you have 12 inches or more it ain't gunna improve until we have 3D scopes with 1O80p and even then it will be false colour?
I guess some time in 2075 AD we will have colour scopes, 1 hundred years after colour TV!

barx1963 (Malcolm) · #26 06-01-2015, 06:47 PM

Quote:

Originally Posted by creeksky

Well I missed out on an 8 inch Dob, So perhaps best to go with a skywatcher 130p?
I haven't yet (apart from planets)even 10 inch, seen any colour in DSOs unless filmed with a camera and registax post process.
Seems the universe is all black and white and unless you have 12 inches or more it ain't gunna improve until we have 3D scopes with 1O80p and even then it will be false colour?
I guess some time in 2075 AD we will have colour scopes, 1 hundred years after colour TV!

For VISUAL observing it is not a matter of technology, simply size, get a big enough scope and DSOs will have to exhibit colour, problem is you need a VERY big scope, even the Mt Wilson 60" in the USA shows little according to people who have used it for visual observing.As for "false colour", if you think about it all colour is false colour. there is no intrinsic difference between red light and blue light apart from the wavelength, it is our brains that calls it "red" or "blue".
I would still encourage you to save up for an 8". Having used both sizes when I first started (ie: 130mm versus 8") I know which one I would prefer!
If colour is an absolute must for you, then unfortunately you may have to go the video or imaging route. Start saving now!!

Cheers

Malcolm

raymo · #27 06-01-2015, 07:35 PM

Sorry to rain on your parade Pete, but colour TV came out in Australia
around 1975, but came out in the U.K. some nine years earlier, and in the U.S. some twenty years before that, around 1947, although in the case of the U.S. the colour was horrible, all saturated reds. Looks like we should have our colour scopes by 2047 then. Won't help me though, I'll be long
gone.
raymo

creeksky (Pete) · #28 07-01-2015, 03:46 PM

1-so if I was to get a brand new 8' Dob would it need colminating?

2-Do they all come with a fan that needs to cool the mirror?

3-Do you have to use the fan or just let the scope sit out side for 30 mins ?

4-The finder scope looks awkward to use ie: looks like you have to bend your head sideways?

I sometimes get heavy dew is that a problem?
can a small person lift and carry it?

barx1963 (Malcolm) · #29 07-01-2015, 04:33 PM

Pete
1. Yes, but collimating is very simple, and once you have done it a couple of times it get easier. My 20" needs tweaking but usually no more than 1-2 minutes per night.

2. Usually yes.

3. Depends. If it has been sitting in a warm room and it is cold outside, the fan helps. Remember you are only trying to cool the mirror to the ambient air temperature, so if it is a warm night, not such an issue.
Having said that 8" mirrors cool fairly quickly, but solid tubes slow down the process so best to always use it.

4.Most 8" dobs (eg this one http://www.bintel.com.au/Telescopes/...oductview.aspx ) have a right angle finder which is the most comfortable to use and gives a correct image. There are straight through finders but they are more uncomfortable and give a reversed image.

5. Dew can be a problem, but mostly for eyepieces. Solid tubes usually have no issues with the mirror, but in my 12" is sometimes had issues with the secondary. There are a range of anti dew solutions. Simplest is a 12v Hairdryer (easy to find on ebay) and a 12v battery and ciggy plug.

6. Easy to handle. It splits in 2 with the tube and base separating and the base has a carrying handle. remember you only have to move it twice a night! Once out and once in at the end.

Hope this all helps

Malcolm

creeksky (Pete) · #30 08-01-2015, 09:41 PM

Thanks Barx1963 and others for all your help, you are right the bigger Dob is the better.
I have researched like mad, I even have had multiple
Dreams of shuffling and puttting EPs into perspex holders?

Last night I used up 1 GB of my 8GB monthly allowance (on wireless) on youtube comparing what I would see with an 8 inch, which would be fantastic,compared to a lower Dob.
But today I discovered all my lawn mowers are cactus.need a new one.(will need at least $300 to buy one.
So unless a 8" appears for sale around at most $300, I will have to go for a skywatcher 130p.
No good Skygazing with 1 foot high grass and snakes!
Probably a payback for selling my 20mm refractor in 1987, should have kept it.
I will just start from scratch, learn the sky and constelations, with the 5 inch, but I will save up for an 8 - 10 or even a 12 inch in 8 months time.
Thank y

ou for all the good advice.

Kunama · #31 08-01-2015, 09:50 PM

This might help with your choices Pete and will give you a fairly realistic idea of what you will see with a particular scope
Just input the details of any scope into the relevant boxes, select an eyepiece type and focal length and the click on the 'view' option .... enjoy

http://www.ar-dec.net/vsa/

barx1963 (Malcolm) · #32 08-01-2015, 10:14 PM

Pete
Always glad to help. One of my philosophy's is that any scope is way better than none. If the 130 is all that you can get, go for it and learn to get the best out of it.

Cheers

Malcolm

creeksky (Pete) · #33 09-01-2015, 03:21 PM

I found an 8" for $300
I can't see it until tomorrow its 3hr from me. fingers crossed

Please read my pm to you Barx1963 need your advice on it
its one year old used a handful of times,just in a driveway.

I know they have a fan,does the power to use that come with them usually, or do you need a separate power pack?
Do I have to use the fan? and will it need colimating?

inertia8 (Australia) · #34 09-01-2015, 07:45 PM

Pete,

Power will usually come from a little battery pack and is plugged into the scope, this can be replaced by a powerplug of the appropriate voltage and amperage (not much) and polarity. There will be a socket somewhere on the bottom of the scope and power is simply plugged in.

The fan is used to speed up the cooling of the mirror and tube and I guess you would run it for the first 30mins or so whilst the scope cools to the outside temp.

Collimating? After a 3hr drive home it may well do. See Astrobaby's guide for a good explanation.

creeksky (Pete) · #35 09-01-2015, 08:10 PM

Quote:

Originally Posted by inertia8

Pete,

Power will usually come from a little battery pack and is plugged into the scope, this can be replaced by a powerplug of the appropriate voltage and amperage (not much) and polarity. There will be a socket somewhere on the bottom of the scope and power is simply plugged in.

The fan is used to speed up the cooling of the mirror and tube and I guess you would run it for the first 30mins or so whilst the scope cools to the outside temp.

Collimating? After a 3hr drive home it may well do. See Astrobaby's guide for a good explanation.

Thanks,I have read astrobaby's guide and went into brain lock...
don't know where I can get a film canister lid from maybe cordial lids will surfice?
I plan to take every cushion pillow and doona with me I can find

creeksky (Pete) · #36 09-01-2015, 08:44 PM

Just spoke to the owner.
He has never collimated it,didn't know what that was? (neither did I 3 weeks ago) he was a raw beginner after going to a star party,decided to buy one to begin the hobby but has no time to- with a young family.

Literally used 4 times,to only look at Saturn (he could see the rings clearly)and our moon.

Its never been in car except from day one from store to home.

FAN. he didn't know it had one? doesn't think it does and had was never told or read in the manual that it needed batteries or power for a fan.
Don't all 8* inch dobs have fans?

Its never been knocked always had dust caps on after the little use.

Monstar (Johnny) · #37 09-01-2015, 09:06 PM

I have the Heritage 130 and its a great scope. If you don't like the table top it's easy to mount, I've had mine on an EQ5, an alt/az mount would be even better. It's easy to collimate because you don't have to move from the EP to adapt the primary.

I could go on all night about its advantages but the fact is I wished I'd gone for more aperture and got an 8".

raymo · #38 09-01-2015, 09:18 PM

Most budget level Dobs up to at least 10" don't have fans. Some larger ones don't.
raymo

creeksky (Pete) · #39 09-01-2015, 10:39 PM

Ok thanks,
Am I going to see much with the included EPs,just realized EPs will be expensive and read its no good buying the cheaper ones.
It comes with
10mm and 25mm 1.25" Super Plossl Eyepiece
includes a 2" focuser with a 1.25" adapter, allowing the use of either eyepiece size.
Its a saxon 8 inch.

inertia8 (Australia) · #40 10-01-2015, 12:36 AM

Pete,

Having been a little silly and bought ep's before I got a scope, I would say start off with the included ones and find out where your interests lie when looking at different objects in the sky, then you will get an idea of what sore of zoom and field of view that you want. The 10mm will give you 120x and the 25 about 48x.

As you know, I'm no expert, but I have found the GSO Superview 15mm to be a great budget eyepiece and if my little dob had a 2" focuser I'd definitely consider the 30mm SV as well for pondering about the sky.

EP's don't have to be expensive, the Agena Astro Dual ED / BST Starguider ED and Celestron Xcel LX seem to get plaudits in the budget range and in a scope such as that Saxon, which is close to f6 focal ratio, you will find that it will not be too harsh on eyepieces. I've had to stop myself buying any more eyepieces as I am finding that I really do need > 15mm eye relief for comfortable viewing with my eyeglasses. Whilst I can take the glasses off and get a pretty good view with a bit of re-focussing, it is still noticeably crisper with the glasses on.

As I said, start with what it comes with and go from there. I don't regret the GSO SV 15mm, but for other EP purchases I'm going to wait and put a little bit of money aside so that I can make a more informed purchase (ie: after going to a star party or two and looking through other's EP's.)