300 dob or 250 goto

[Kendo_Fuzzy]

Hi all,

I've been using a SW 130p goto for the last year and am itching to upgrade.

I spent alot of my time imaging even with the alt-az limitations as im into photography but feel I kind of brushed past just observing.

So reading every post and article id set myself on a SW 250px dob(nongoto).

this rapidly turned into me obsessing about bigger scope! More light! Until I got into thinking about the SW 300p flex dob, but did it stop there? Heck no. I then thought I'm now up around the price of the SW 250px goto. And that's where I've been kinda sitting. Having never used nudge,nudge dob I'm drawn towards the 250goto, but then I read that with low power eye pieces that the 300 would be better.

So can anyone with more experience in using non goto and goto dobs or scopes at the 10-12 inch size help me decide.

Many thanks

Fuzzy

[John]

If your main interest is deep sky objects then all aperture is good. A 12" scope is substantially larger and heavier than a 10" so thats worth bearing in mind.

They are both a major step up from your current scope of course.

I've not bothered with GOTO myself (other than on one scope many years back) so I'll always trade technology for viewing potential. I've used 10" and 12" manual dobs at magnifications up to 300x and nudging soon becomes 2nd nature although I do use ultra-wide angle eyepieces which makes that task quite a lot easier - the eyepieces have cost around 3x as much as any of my scopes though !

[Kendo_Fuzzy]

Hi,

Thanks for the input. I did enjoy doing webcam planetary stacking which i gather would be a bit rough with non goto?

[Moonshane]

if you want to do any kind of imaging them you need a tracking mount - would definitely be advantageous. visual adtronomy for me at least is benefitted by larger aperture and 12" is a great aperture (although 10" is not too shabby either!). as John says though, the difference between a 10" and a 12" f5 is substantial, not so much with a 12" f4 but this requires a coma corrector and good quality EPs so costs start to rise a bit.

If I had the choice between 10" with tracking/GOTO or 12" manual I'd go for the latter every time.

If I were imaging even just planets I'd want a tracking mount but imaging is not for me.

[Rossco72]

A couple of things;

How's your light pollution and how well do you know your way around the sky?

I have the 350 flextube goto, although if you look on the forum you will see my trials with the GOTO not being so good on mine.

That said the larger mirror gives astounding views and objects which i simply can't see in my 100mm frac are just there!

A dark sky helps if you are manually finding objects in my experience, if you have light pollution and need to use filters / photography to see whats there then the Goto is a great help.

As John highlighted though, these are big scopes, my 14" doesn't even fit through standard doorways in the UK so do bear in mind the size if you are buying one without seeing it first.

Regards

Stuart

[Kendo_Fuzzy]

Hi

Part of the reason i wanted non goto was to help me improve my knowledge, I'd never really thought about that with bad quality skies it would make this difficult.

Although the thought of the extra light gathering is appealing I think the hiring is starting to look like a better option for me.

Thanks for your help

Fuzzy

[Sarah]

Either would be good! It may partly come down to size and weight. If you can check them out in the flesh, then I would recommend you do this. We have both a manual dob and a goto dob. The manual dob is great and nudging is very easy. Minimal set up and pack down. Yes it can take longer to find objects, but that can be rewarding when you find something new.

We opted for a goto with the larger dob as we prefer to have the object tracking and staying in the view, particularly when we are taking it in turns to looks through the eyepiece. We are really pleased with the FlexTube GoTo. We have found it works really well. It suits us, but a GoTo dob isn't for everybody.

When we first went for a dob, we went with a 12" solid tube manual dob. It was a great scope and very easy to use. The only reason we sold it was because we bought the 12" FlexTube to take to star parties. The solid tube was too long to fit in the car boot!

A word of warning though, a 12" dob does not cure aperture fever. We have just got a 16" dob to help treat our aperture fever!

I don't know what you have read about eyepieces being better in the 12" over the 10" dob. As you mention low power eyepieces, presumably you are referring to exit pupil? Exit pupil will vary between people, so a higher exit pupil may be less of a problem for some people and more of a problem for others. We have used a 35mm eyepiece in the 12" dob (at f/4.9) and it gave us nice wide views, although it did lack contrast. We didn't realise this lack of contrast was due to the exit pupil, until we used the same eyepiece in our new f/4.4 dob. At f/4.4, with the exit pupil increasing, the lack of contrast was even greater and the views were quite disappointing. So yes the 10" dob at f/4.7 may be a bit worse than the 12" at f/4.9, with a low power eyepiece. I've seen a few people go for a higher mag, wider field eyepiece (82 or 100 degrees) that provides a wide field of view but with a lower exit pupil. We followed this approach and opted for a 21mm 100 degree eyepiece. It was expensive, but the difference in the contrast is so much better! And it still gives us a similar field of view to the 35mm eyepiece.

I would probably opt for the extra aperture over having GoTo. There are lots of threads on here where people have added a Wixey and setting circles to their manual dobs to help with finding objects. But if you felt that the 10" would be the largest you could manage, then it might be tempting to add the GoTo, if you have the funds available. Alternatively, go for the 10" manual version and then use the spare cash for some eyepieces!

[Kendo_Fuzzy]

Oops sorry about the confusing "hiring" in that post. Damn auto correct

[Kendo_Fuzzy]

Thanks for the very informative post Sarah.

This has only gone to swing me back to the manual 300p.

Another point : Lets say I get the 300p, will the desire to hunt DSO's overtake the urge to do imaging? etc. or is it a case of getting this to satisfy my need to "view" more and then get more

scopes later to satisfy any imaging itches I need scratched?

That all makes sense in my head i think....

Fuzzy

[Moonshane]

I don't hold with the idea that aperture is not useful in light polluted areas. everything (without exception) that can fit in the field of view looks better when using my 16" dob and I live it very light polluted skies near Manchester.

[Kendo_Fuzzy]

Thanks Moonshane, this is the kind of opinion Im finding very helpful.

Fuzzy

[Sarah]

1354194300[/url'>' post='1722281']

Another point : Lets say I get the 300p, will the desire to hunt DSO's overtake the urge to do imaging? etc. or is it a case of getting this to satisfy my need to "view" more and then get more

scopes later to satisfy any imaging itches I need scratched?

At the Kelling star party this year, we had so many 'best ever' views, with the 12" dob. It really is a great scope! Most of our observing is with a dob. We have other scopes for imaging and they might occasionally be used for visual too. For me, my interest has probably been a fairly even split between visual and imaging. I think hubby was a little bit more into the imaging than visual. Now with the new dob, the visual is pulling us both back in a bit more!

[Kendo_Fuzzy]

Thanks again Sarah,

I feel like a scope tennis ball, each time I say "right this is what I'll get!" I start thinking about the other option. Even now, with excellent job you've done of swinging it towards to 300p im still thinking that i could at least do some imaging with the 250 goto as well as having a more than reasonable visual dob.

It's like Sophies choice. lol

Fuzzy

[Paulb3098]

Fuzzy,

I went from a 150PL eq3 manual to a 250PX dob goto and just love it. If I had better weather I would have probably stayed with a manual scope but I want to spend as much time looking at objects as possible, which I'm afraid the UK weather doesn't permit. IMHO, owning a goto doesn't stop you learning your way around the night sky, you just get to see more of it, and the 10" scope is manageable lump to move about.

Good luck

Paul

[MarkMayf]

Are there any limitations imaging wise with the 250 goto dob?

Does the low f ratio cause any problems?

[Naemeth]

Are there any limitations imaging wise with the 250 goto dob?

Does the low f ratio cause any problems?

If tracking with AZ, then images produced will be blurred due to the scope having to move on two axes, rather than one for an EQ mount. It would be difficult in all honesty to mount a 10" scope on an EQ mount, and you would probably have to get a premium/observatory class mount (Mesu Mount 200 for example, which is ~€4000), the long focal length would make tracking need to be very accurate, and it's really all too much hassle. An SCT would be a much more compact system, and easier to work with, but only really good for planets.

Aperture really doesn't matter for DSO's for imaging, because the light is gathered by the amount of exposure you have in astrophotography.

HTH

[Sarah]

1354200847[/url'>' post='1722381']

Thanks again Sarah,

I feel like a scope tennis ball, each time I say "right this is what I'll get!" I start thinking about the other option. Even now, with excellent job you've done of swinging it towards to 300p im still thinking that i could at least do some imaging with the 250 goto as well as having a more than reasonable visual dob.

It's like Sophies choice. lol

Fuzzy

Whilst buying astro gear is fun, it can be a bit of a headache deciding! I've not tried planetary imaging with the dob, but if that's what you are interested in, then probably the 10" GoTo would be better suited and still give you that increase in aperture to be a great visual scope! As I said in an earlier post, we have been really pleased with the GoTo on our new dob, so I am sure you won't be disappointed whatever you decide to get!

[crashtestdummy]

If you are interested in imaging you have to go for the goto regardless of any other considerations imho

[Kendo_Fuzzy]

Much appreciated input everybody. I think the 250 goto will ultimately tick more boxes for me than the 300 manual.

I was nice to bounce it around people who quite obviously have suffered with a similar dilemma.

Thanks again for helping me with the decision.

Clear skies

Fuzzy

[jezhughes]

This decision will entirely depend on your mount.

As a 250 owner i can tell you all about the weight problems you'll experience even on an NEQ6. I am in a constant battle shaving grams off my rig to get a good imaging performance. I initially wanted a 300 but i would see that as out of the question now unless all you want to do is observe.

otherwise you can wait for the new NEQ mount next year which i believe has a higher capacity.

If you want to image you're better off getting a Quattro

[Kendo_Fuzzy]

Thanks for the info Jez.

I am starting to think along the lines of maybe getting a 250-300mm manual dob, and then getting a 127mm mak to put on the alt-az goto mount Ive got for imaging planets.

I think this will give me more options as originally the dob was a purely visual idea, with the imaging being a fly in the ointment.

Personally I blame my GF, when my ideas started getting the better of me her response was "what difference does it make to me what scope you get?"

Suddenly I was like a puppy with no bounderies or limitations other than my own conscience, which once the aperture fever took over was no where to be seen.

So in some way Im back to where I was when I reached out for help, too many options, too many scopes.

Fuzzy

[Kendo_Fuzzy]

Which would be better?

A 127mm mak for imaging / planetary with a 250mm Dob for DSO viewing

OR

a 250mm goto auto dob for both?

[Scott]

If you're entertaining the thought of imaging, forget a dob. you will probably get some good results on planetary but sooner or latter you're gonna want to image dso's and for that you need a good eq mount. I would sugest you try to decide whether you want to do visual or imaging for the time being. If its visual,get the 300 dob or the 250 goto but don't choose the goto for imaging. choose it to make viewing more comfortable. if its imaging get a good eq mount and possibly a apo if budget allows. you won't get both from the one setup so you'll have to choose. sorry if this isn't what you want to hear but i'm just trying to be the voice of reason. on a side note, goto doesn't stop you from learning the skies, it has an off button

Scott

[Kendo_Fuzzy]

Thanks Scott,

When I first started thinking of a visual dob I was completely sold on the SW 250px manual, this seemed to be everything I was going to need. It was only when I started thinking "I might as well get the goto, use it for visual but I could do some planetary imaging/stacking", but I guess Im trying to justify the hike in price between the manual and goto. The only thing I can use to justify the difference is being able to do some basic imaging, as I didnt want the goto for anything other than tracking the object I was viewing.

Thanks for your thoughts

Fuzzy

[russ.will]

.....her response was "what difference does it make to me what scope you get?"

You have failed to read behind the lines, I fear. What she specifically did not say was get two scopes. Trust me; When it comes to what she didn't say, my wife has total recall.

Russell