Dobsonian vs SCT

Murat (Mark) · #1 28-12-2010, 11:59 PM

Hi Folks,

This is my very first thread.

I am, as many of you are, busy enough in my income earning profession to have few hours to spare for a fascinating hobby like astronomy. However, the hobby has captured me enough to want to spend a few extra bucks. I purchased six months or so ago a pair of binoculars Andrews 20x80s, which have enabled much 'backyard astronomy". I expect that due to family and work I will spend the vast majority of my time in my backyard with this hobby.

I am not particularly drawn to one aspect of astronomy or another, it all seems so exciting that I cannot narrow down my interests to DSO's, binaries, or doubles, or solar events, or planetary pehonomena alone. I want to wander freely on the pastures to see where my learnings take me. I think this path of "general" interest will carry me for a decade before I narrow down to one area alone, and perhaps this is reasonable.

I now yearn for better viewings from my backyard, but am not certain if I want to photograph it, and I am worried that if I don't buy a very big scope that I will not be able to play with photography.

I also want to be cost effective with this purchase.

I am advised that a DOBSONIAN is a great Noob's scope in astronomy, as it will give you the aperture for fine viewing at an affordable, or "cost effective" price tag. I would happily afford the 6 - 12 inch DOBS. Though serious photography is not done with these. They are also limited in their GOTO accesorisations, noting that some newer GOTO DOBS are on the market.

I was advised that the SCT's were a good buy.

I have seen the Celestron Nexstar 6SE thru to 8SE"s and prices range from $1600 to $2500.

I suspect that whichever way I go, a whole bunch of accessories are going to be made essential to make the purchase complete, to the tune of about a few hundred bucks on top of the scope purchase. I suspect these will include eh eye pieces which I will be told dont come with the scope.

for a hobbyist who is uncertain for how many decades he will continue this passion, which is the better direction to start with? Should I expect that I will evolve from one scope to another purchase and that this first scope will be a stepping stone?? Or should I buy the BEST that I can, noting that this is a hobby.

I am looking at purchasing from Bintel or Andrews in Sydney.

I suppose I am looking for wisdom rather than a clear answer here.

I wish all of you a healthy and content New Year!

http://www.iceinspace.com.au/forum/....es/family1.gif

Thanking you in advance.
Murat

Jeeps (Sam) · #2 29-12-2010, 12:29 AM

After using a cheap scope for a few years and being frustrated with it's wobbly tripod, terrible mirror and eyepieces I threw it away and convinced myself that i would settle for nothing less than a GO TO scope.

I wanted a celestron or Meade computer controlled scope etc. However i took the "aperture rules" advice and bought a dob. I've been impressed and have no trouble finding objects (usually) and i am a fan of simply taking it outside, plonking it on the ground and away you go.

I have no doubts that i will eventually get a go to scope but this dob should suffice for a few years. I might not ever get rid of the dob either

Cheers

ballaratdragons (Ken) · #3 29-12-2010, 01:06 AM

Quote:

Originally Posted by Jeeps

After using a cheap scope for a few years and being frustrated with it's wobbly tripod, terrible mirror and eyepieces I threw it away and convinced myself that i would settle for nothing less than a GO TO scope.

I wanted a celestron or Meade computer controlled scope etc. However i took the "aperture rules" advice and bought a dob. I've been impressed and have no trouble finding objects (usually) and i am a fan of simply taking it outside, plonking it on the ground and away you go.

I have no doubts that i will eventually get a go to scope but this dob should suffice for a few years. I might not ever get rid of the dob either

Cheers

Fantastic advice

Mutley (Paul) · #4 29-12-2010, 02:24 AM

See if there is a club near by and try out a few of their scopes before you make a decision OR a better way to go would be to contact a few members in your locality, arm yourself with a "six pack" and have a look through theirs. All scopes have +'s and -'s and you should get some good advice from fellow members. And what ever you decide keep your eye out for the New Year sales

Good luck and Happy New year. Atb

ZeroID (Brent) · #5 29-12-2010, 06:22 AM

A Dob is a great starting point. As you say you are not sure where this interest will lead you so buying the 'correct' equipment is a big question mark. Get a biggish Dob 8-12", it's a relatively cheap way to get sme real views and fan your interest flames. When you figure out what you really want to do then it will still fetch a goodish oprice secondhand or you probably still hang onto it for those pure visual nights. My 10" was the best 'bang for buck' I've spent. Join a club also.

wavelandscott (Scott) · #6 29-12-2010, 07:21 AM

As suggested, go to an Astro Club/Society meeting before you make a purchase.

Most new moon weekends there is a group of IISers that get together at Mangrove Mountain.

Take the time time to see and try a few different types of scopes and see which one you like.

Each telescope design is a compromise that has its strengths and weakness. Your own preference will determine which scope is right for you. Me, I'm a fan of reflectors and refractors but others are fond of SCT.

Second hand is not a bad way to dip your toe in the water.

Cheers,

casstony · #7 29-12-2010, 12:20 PM

Hi Murat, whatever type of scope you buy I'd urge you to go for a minimum of 10" aperture to help combat light pollution associated with in-town observing. I find that 8" is not quite enough to properly appreciate DSO's froom the backyard.

barx1963 (Malcolm) · #8 29-12-2010, 12:59 PM

Hi Murat
For the dollars you are talking about the go to SCTs are going to leave you with small aperture, and in this caper aperture rules. Having a 12" dob and suffering from some light pollution myself, I know that a lot can be done with a scope of this type. You mention serious photography. You will find most serious astro imagers these days use refractors on GEM mounts rather than fork mounted SCTs which are more likely to be found on wedges in permanent observatories.
I would look at 2 ways of going
1) a 12" dob which can be picked up for around $1k these days and spend the rest of you budget on good eyepieces, specifically Televue Naglers and or Panoptics and a really good set of charts. The current "Gold Standard" is Uranometria 2000 which will set you back about $350 for the complete 3 vol set
2) Get a smaller Go To dob say 10" and get some good EPs

Malcolm

Murat (Mark) · #9 29-12-2010, 01:54 PM

All you guys are so charitable with your advice...thank you!! It is an association that I have made that people interested in astronomy are very nice people in general. Point proven once again.

I am warming to the bias of a 12inch Dobsonian and will get the necessary accessories. Any recommendations for Brand or types of eyepieces to get? Collapsible versus non collapsible?

I need to make some time for a night out with the troops also.

Murat

Strawb (Dave) · #10 29-12-2010, 03:50 PM

Hi Murat,

As a very new astronomer but getting senior in years also I jumped in with a second hand SCT which I enjoy heaps as I do want to develop my imaging skills. However I have to admit to spending time with the wifes 8" collapsible dob last night and enjoyed M42 particularly to the point where I'll have to get another ep for it methinks. I'm honestly thinking of getting a bigger dob to take to star parties and leaving the SCT setup in the obsy ( when I get it that is eh dearest wife

) because the dob is just so user friendly for the visual observer. Advice given to me earlier this year when starting out was to get the best scope I could afford and let things develop from there Good luck which ever way you go.

Dave

floyd_2 (Dean) · #11 29-12-2010, 04:20 PM

Hi Murat,
it's a little more difficult to buy a scope on a budget that has large aperture, and that also allows you to dabble in photography if you decide to go down that path. I think the other guys have nailed it in this thread. Go for the biggest dob that you can afford, remembering that you need to be able to move it out under the stars when you want to use it. If its too heavy for you, or needs two people to set up, you might find this to be a limiting factor to observing.

I have a 14" Orion XX14i on wheels with leveling bolts for visual. I wheel it out of my observatory when I want to use it and level it up. When I want to do some photography, I use my 10" SCT (again on wheels with leveling bolts). It's possible to get yourself a larger / heavier scope if you don't mind doing a few minor mods to make sure its still nice and easy to set up.

I must say that one of the good points about the Orion XX series dobs is that they have an object locator built in. You just do a two star alignment at the start of the night and then use the hand controller to locate the objects that you're interested in. Whilst this may take the joy of star hopping away, you'll certainly see a lot more of the sky on any given night.

Don't forget to set some money aside for some eyepieces if you don't have any / many and perhaps a red dot finder.

Best of luck with your decision.

Dean

multiweb (Marc) · #12 29-12-2010, 04:40 PM

Dobs would be best for large aperture. A big SCT is not ideal to move around for astro-photo down the road if you want to do some. Some interesting photos can be taken with large dobs as well. It's just a different process to capture and track but the results are very good. At the end of the day how big is your car

higginsdj · #13 29-12-2010, 06:57 PM

I started off with what I thought was a large scope - a 114mm Tasco reflector. Within 3 months I ditched this one and purchased a goto SCT (8" Meade LX-90). My biggest issue with that first scope (the Tasco) was trying to find something to look at. If you can't find it then it doesn't matter how big your scope is - you're not going to see it.

BUT before you go down the SCT line note that my interest has always been in recording/photographing what I see and now it's research level imaging through a 14".

If you do not think you are going to take the time to learn to star hop, read star charts or learn the stars then a GOTO is going to be your best companion. If you are willing to put in the effort to get to know your way around the skies then the DOB is the best bang for your buck.

BUT, you must also consider the size of the scope. The bigger it is, the more effort it will be to get it out, set it up then put it away again at the end of the night. A collapsible DOB will take as much time and effort to set up as an 8" SCT. A 12" DOB is going to be heavy, a lot heavier then an 8" SCT (I wouldn't waste my time with an SCT any smaller than 8" by the way).

Just my 2 cents worth

kustard (Simon) · #14 29-12-2010, 07:41 PM

I've always been a fan of the short tube SCT, having owned 2 x 8" and last year I upgraded to a 9.25". The 8" SCT's were stock fork mounted scopes which taught me to star hop and learn the sky (the first scope was stolen, thus I owned two). The 9.25" is a goto scope the reason being that I now know the sky and want to maximise my observing time.

BUT... I will often find myself drooling over 12"+ dobs purely for that aperture lust. And these can quite easily be converted to tracking/goto systems.

As others have said, if you can fit it in your car get the biggest you can get. An SCT is a good choice as they are short tubes but if you crave faint fuzzies then you'll need aperture and lugging a large SCT in your car can be painful.

A second hand scope to start with can be a good way to get into the hobby without spending a packet and once you have an idea of what you might want to observe and if you wish to get into astro-photography then you can easily upgrade, in fact do not be scared of the upgrade path, it is a viable solution in this hobby.

Murat (Mark) · #15 04-01-2011, 10:10 PM

12" Meade Lightbridge Dobsonian

+ 15mm Tele Vue Plossl eyepiece
+ Blue, Yellow and Moon Filters
+ Planisphere
+ Astronomy 2011 magazine
+ Laser Collimator
+ red LED variable intensity light

for $1400

I set it up with music (on my blackberry speaker) in the background and coffee (Blend 43; I make a mean Blend 43!!.

I have to say I spent much time contemplating fancier scopes, but remain uncertain as to whether I wanted these because they were there, or because I was interested. I will find out over the coming decade where my interest takes me, and I look forward to it.

The concept of star hopping (or hunting), is exciting.

Also, the fact that today is cloudy in Sydney makes the metaphorical "stars align" for me with the purchase. If I were really that superstitious (pff!)!! I am told bad weather should be the expectation for any astronomer on the day of their new scope purchase. This delay only adds to the anticipation and excitement so my glass remains half full. After all one needs bad weather time to prepare for the hunt!!

Radiation (Tudor) · #16 05-01-2011, 12:33 AM

I have a 12" lightbride and I love it, it won't disappoint.

However you might want to consider getting rid of the red dot finder and adding a Telrad and a finderscope, makes star hopping much easier. You may also need to weight down the other end of the tube.

AG Hybrid (Adrian) · #17 15-01-2011, 12:05 AM

I'm in the market for a new 12" myself. Just watch out, been reading Cloudy Nights about Lightbridges. They lose colimation as it goes through its alt/az motions.

AstroJunk (Jonathan) · #18 15-01-2011, 02:12 AM

Murat, Great choice to get you into astronomy in style. Well done.

Quote:

Originally Posted by Radiation

However you might want to consider getting rid of the red dot finder and adding a Telrad and a finderscope, makes star hopping much easier. You may also need to weight down the other end of the tube.

And good advice too. Murat, welcome to the world of tinkering and upgrades before you even get your new plaything