SCT vs dobsonian - much doubt

[cevinator]

Hi,

People trying to decide what is best for them is not new here, I've read many threads like that and apparently I'm in the same boat. I'm really interested in the night sky, planets as well as DSO, as long as there is some magic to it let's say. So I actually want to buy my first real telescope. I try to stay below 2500 € if possible, I'm guessing this is quite the budget for a first telescope. But obviously I want something that I won't outgrow immediately. Also I'm not at all interested in imaging and all that stuff, so thats a big factor in my choice I guess.

So I've been checking things out and I kind of narrowed it down to 2 types, the SCT or the dobsonian, more specifically the celestron 8SE + goto which goes for about 1500€ where I live, or for a dobsonian I was looking at the skyquest XT10 intelliscope, which goes for about 700€. Alot less compared to the celestron nexStar 8SE (btw I also checked the CST 9.25 but they are a little out of my league if I want to buy some decent EP's too). I could spend the extra money I save by buying a dobsonian on better EP's, so eventually the views I'll get from this XT10 will be alot better comapred to the 8SE, is that correct? Will it be really a noticeable difference, though?

Two things that bug me about these dobs is their size obviously so I'm afraid I might not be using it that often if I will get bored of carrying it everywhere? I'm quite a big athletic guy though, so maybe I'm making too big of a deal out of it. I live in Belgium, and as you can see from light pollution maps, Belgium is having quite a big party. I might be moving my telescope to other places alot so I might have to consider mobility. Anyone having experience with both of these telescope to weigh in on this? What I'm also concerned about is the viewing position of the telescope. I'd like to have a kind of relaxing position to watch the stars. I cannot get carried away if I'm standing, you see . Am I right that this could be more of an issue for a big dobsonian than for a smaller SCT? I'm guessing with a tripod you can always get into a viewing position which is kind of relaxing, is this correct?

[nightfisher]

To answer a couple of points for you:

first, do you drive a car, if so a dobsonian will fit in a reasonable size car, some thing like an Astra or similar hatchback, this will allow you to take a dob to a darker site, set up is very quick, put base on ground, fit the optical tube and your done

second, i would think a dob is more comfortable to "sit" beside and view, the dob will give very good views of both planets and deep sky though the C8 is also a good performer 

[tony gazer]

it all depends on what ur going to be trying to do dob easier to set up but the  sct takes up a lot less space and can also sort of manage to track with if set up right but setting up will take a lil longer

[CodnorPaul]

If you go SCT get the CPC not the SE - much more stable Mount. I love my SCT and the views are fantastic in a portable package - but you pay more for it. As for comfort at the EP there isn't much in it at the size you are looking at on an alt-az mount - only difference will be what height to set your seat, and a seat is a must, more important than EPs to me. If your not comfortable you won't linger at the EP long enough to tease out detail.

I prefer SCT views - much clearer and sharper to me than mass produced reflectors, and for a premium reflector you pay similar money to the SCT so lose the saving benefit. But Dobs have a lot of fans, and if you want bigger than 12" they come into their own.

[Gazabone]

Hi Cevinator,

Firstly, I'm pretty new to this hobby too so I wouldn't like you to base your decision purely on what I say.  However I have a 10" Dob and a nexstar 6SE.  The big advantage for me is that the nexstar is a goto whereas my Dob is completely manual.  My current frustrations are that the nexstar has developed a "boot error" so cannot use the mount - I've struggled to correct it - I can't get either my laptop or desktop computers to run the Celestron Firmware manager, but have recently bought a MacBook which runs it fine, the next problem is I have to connect the mount using a RS 2332 cable - won't connect and the only advice is connecting with the RS2332 cable adaptor is "notoriously difficult" so at the moment I can only use it on my AVX mount.  That's OK except I can have the nexstar mount up and running in about 15 minutes and with the help of a 12.5mm illuminated reticle eyepiece at the alignment stage, the accuracy is stunning, everything I slew to was bang centre of the eyepiece (so I would strongly recommend getting one of those if you go for a goto mount that needs you to align it - I got the Saben one from Amazon - about £30 - sorry FLO).

Using a Dob (assuming it's neither Got or Pushto) will help learn the night sky and it's easy to find planets Jupiter, Saturn and Mars with and some of my favourites like M13 and Andromeda Galaxy) but I haven't got the hang of star hopping yet (only recently really started to try and learn it).  Certainly DSO will be hard to find in the early days but well worth persevering with.

An accessory you haven't mentioned but from what you say, you might find really useful is an astronomy chair, basically a variable height chair - one of the best things I've bought for the hobby -  around the £100 mark.

It's always said that you get more bang for your buck with a Dob because of it's simplicity, touch up maintenance is, in my experience, more frequent but a lot easier than a SCT but that is mainly collimation - difficult with a SCT, but very easy on a Dob with a laser collimator.  When I go out I quite often find the Dob less hassle than the SCT, yes, it's big and bulky but quite light.

Whatever you go for, I hope you really enjoy it.

[cevinator]

Thanks everybody for the quick replies. Everybody is here to help, that's really nice .

I do have a car so I guess it is not that much of a problem. But of course if I would like to go to France for a vacation for example, I do need more than just my telescope to survive, so less volume still is better.

I'm interested in what CornorPaul has to say. I guess the better mount makes it less wobbly and more enjoyable (also makes it 400 € more expensive though). But what about the different SCT views? Why are they much clearer and sharper than a dobsonian? Is this more of a personal thing or do more people agree? I've read somewhere to let a dob really shine, EP's are quite important, while less so for SCT's. Does this come into play here? This is quite important to me. To be honest, I'm a little in love with the design of a CST, but I know that shouldn't influence my decision too much if I have not too much problem with the mobility of a dobsonian. I would say that all in all, quality of the views is probably most important.

Also nice to hear that viewing position is probably as good or better with a dob than a SCT. Guess I don't need to worry about that too much, it will be OK either way. I do have to look up those 'astronomy chairs', though.

If I do decide to get a dob, I think I'll go for a pushto system or a goTo system. I guess I can still use it manually as well? 

[Owmuchonomy]

Thanks everybody for the quick replies. Everybody is here to help, that's really nice .

I do have a car so I guess it is not that much of a problem. But of course if I would like to go to France for a vacation for example, I do need more than just my telescope to survive, so less volume still is better.

I'm interested in what CornorPaul has to say. I guess the better mount makes it less wobbly and more enjoyable (also makes it 400 € more expensive though). But what about the different SCT views? Why are they much clearer and sharper than a dobsonian? Is this more of a personal thing or do more people agree? I've read somewhere to let a dob really shine, EP's are quite important, while less so for SCT's. Does this come into play here? This is quite important to me. To be honest, I'm a little in love with the design of a CST, but I know that shouldn't influence my decision too much if I have not too much problem with the mobility of a dobsonian. I would say that all in all, quality of the views is probably most important.

Also nice to hear that viewing position is probably as good or better with a dob than a SCT. Guess I don't need to worry about that too much, it will be OK either way. I do have to look up those 'astronomy chairs', though.

If I do decide to get a dob, I think I'll go for a pushto system or a goTo system. I guess I can still use it manually as well?

Hi and welcome to SGL. Firstly your questions are very important particularly when starting. The budget you quote is a good one to start off and therefore you should be inquisitive. I am in the position today of comparing my 9.25" SCT (about 7 years old) and my very recently acquired 12" Dob (third hand). Is there a difference? Well I haven't had a lot of chance to compare but I have shared the views through both with friends. So for now I would make the following comments.

The Dob is much easier to set up but that's mainly because the SCT goes on a GEM.

the moon looks the same through both (it's a bright target)

M57 looks good through both

M13 looks nicer through the Dob and Albireo looks much much nicer (colours) through the Dob

I haven't tried planets in the Dob but Mars looks very good through the SCT.

In general, the view through the Dob makes me feel that i am 'There' whilst the SCT is like looking through a tunnel (which is not necessarily a criticism).

Comfort doesn't come into it for me as I think that can be solved easily depending upon your choice.

My Dob is F5, so accurate collimation and a decent 24mm EP made a difference

Most importantly my skies are mag 5/6 so the Dob can take advantage of this I understand but I have yet to qualify that comment due to bad weather.

Any queries please ask.

[CodnorPaul]

Others have commented on the sharper views on planets - and on DSO comparisons against a 10" dob and my C8 they comment it is comparable on clusters, bright in nebula etc. Not tried on very faint fuzzies though.

My SCT is well collimated, not sure about the dobs?

[damnut]

My favourite scope was my 10"sct. I long to get a replacement.!

[cevinator]

Thanks for the comments guys, much food for thought!

Well, good to know the comfort factor doesn't really come into play, I can erase that from the list.

I'm still in doubt, though. Sometimes (like 2 times today, lol) I'm really leaning towards a dob (its the aperture no doubt, it's really getting to me now ;-)). But than all of a sudden too many people go on raving about their SCT and how they love it so much and I start thinking again. No, the SCT is not out of my mind completely yet. A 10" SCT is out of my league though I'm afraid, damnut. I wish it wasn't but I have to draw the line somewhere...

I really have to go to a starparty to check it all out myself and convince myself one way or the other... 

[faulksy]

just for the record, i had a celestron cpc 9.25 that was very good and comfortable to use, i then purchased my orion optics uk vx 14" and i can say that planets are slightly better than the sct but everything else is considerably better in the dob, plus a bigger fov. but the down side is good quality eps are more expensive , but you will be fine with your budget. also allow for colimation tools with the dob or power pack with the goto sct

[Digger1895]

I am in a similar situation and keep changing my mind which to get and at the moment am leaning toward the SCT. But I do wish to make one thing clear which seems to worry people about Dobs, the dreaded collimation!!! The only thing daunting about it is reading so much information, once yo've done it once or twice you will wonder what all the fuss is about. I even found one of the easiest quides, Astrobabys, terrifying just to read. Normally guides offer too much information for me, I'm the type of bloke who says "dammit, just tell me what to do and I'll do it".

So don't let that become a deciding factor, just read Astrobabys guide, identify the steps and follow them.

I recently went to a free viewing night put on by the Brisbane Astronomical Society and was able to look through some nice scopes including 2 of which I was considering, a 10" Dob and a CPC 9.25. They both gave fantastic views but to me the Dob seemed softer, almost an artistic view, the SCT seemed harder and more clinical. Remember these are relative views and also my poor attempts to put into words my views. So I'm now leaning toward the SCT but an not sure about the CPC 9.25, although it is rock solid may just be a little too much beast to be tamed on a regular basis.

[Paul73]

If storage is an issue, consider the SkyWatcher FlexTube Dobs. The top section retracts so that you have a much less bulky item in the corner of the room. They are a bit heavier but take seconds to set up (I have the non GoTo version).

Paul

[todd8137]

Hi ,tough choice as I have both scopes you mention ,

9.25"

Great scope for planets the moon and some of the brighter dso ,imaging wise it's a bit of a job the focal length even with a reducer is not ideal ,for planets and a decent fast frame webcam/or dedicated planet cam great for that eye piece wise mid priced eps perform rather well in mine

16" reflector

This scope as out performed most of my scopes and gives great views even a 10" is a killer,scope,and will perform well from most peoples gardens,take one to a dark site and lots of the fainter stuff pops out

Choose the one you want becarefull as you will have it for a few years to,come

Pat

[Moonshane]

I have never looked through an SCT but have lots of experience with newtonians of various sizes. I cannot see how the view through a well collimated newtonian could be improved upon massively but for the same aperture you will get a much wider field of view (like twice the field), quicker set up, quicker cool down, more compact overall (considering the mount and the scope), less cost and more 'modability' with a standard f5 newtonian.

I am sure SCTs are great scopes and many people love them but based on what I have read they are not for me. I have read about more people moving from SCT to newtonian and never looking back than the other way around unless they are planetary imagers.

If I ever get the chance to look through an SCT then I will but I doubt I'll be converted.

[bomberbaz]

I have read about more people moving from SCT to newtonian and never looking back than the other way around unless they are planetary imagers.

If I ever get the chance to look through an SCT then I will but I doubt I'll be converted.

cough erm thats me. I had a Nexstar 8SE goto and prefer my dob. I am reasonably well built but only 5'8" and I manage with my scope split in two, albeit a flex tube. 

Not sure if anyone has mentioned this above but the XT10 will gather far more light than the 8SE and like you said leave you more spare money for eyepieces. However the 8SE is a lot more foregiving at F10 on eyepieces and so you wont need to spend as much to get the same results, well in a roundabout fashion anyway.

There really are so many options but if I was starting over I wouldnt go for an SCT. 

Ok in thier own right but unless I was building an obs I would bother personally

steve

[Chris]

You can get round the narrower field of view of SCTs by using 2 inch widefield eyepieces, well you can get up to around 1.4 degrees anyway.

Having said this the only reason I have C8 is because I have a small observatory will a high pier, the eyepiece position is perfect for me and the scope takes up minimum space for a good amount of aperture.

I definitely wouldn't get an 8SE, the mount just isn't up to the job, go with cpc instead or the new avx mount if you go with an SCT.

If I didn't have an observatory I would go with a dob! They are cheaper and have wider views but are more demanding on eyepieces as said.

[nicoscy]

To make the 8SE mount perform better, you need to keep the tripod legs half extended and hang a couple of kilos from the bottom of the mount to give it extra stability. Find yourself a decent chair and it is very easy to observe. The 8SE is also very forgiving on eyepieces but if you go with a 2" diagonal then the balancing becomes much harder so take that into consideration. It takes slightly less space than the Dob you mention.

But the 8SE takes longer to cool and has a narrower field of view, if that's important to you. For me it is and for DSO I use my dob. For lunar though I have a MCT on order.

Also, the 2" difference in diameter will make a difference on DSO, so again it depends on what you are after.

Finally, both instruments need collimation. The dob frequently but I find it easier than the SCT.

Basically you need to rank your criteria by priority and then decide (size, ease of observing, weight, cool-down time, aperture, cost, required accessories e.t.c.). Once you decide what your priorities are, the decision will be easier.

[RC4U]

i had a celestron 130.. i just got my new celestron evolution 8" and i did get two inch deag and a ES 24mm 82* ep.. the mount is way better than the se...i own hobby store and have sold a few se's and the evolution is by far way better...now i am not very experianced but i really like the new evo..it is very easy to keep the tube on the mount and carry it..the tripod is very easy to setup and with the internal battery its set to go...i store mine in my detached garage and just walk out and grab the whole setup and start...Myself i just cant keep moving to see i really like to take my eye off and then go back and see the same thing not keep moving...another person like my grandaughter can then see the veiw also...and yes a good seat.....jeff