View Full Version here: : Choice between nudging a dob around or using a manual EQ mount for tracking
Mountain_Wanderer
27-09-2010, 07:49 PM
G'day,
I'm looking around for my first scope and seem to have come down to a choice between either a:
- Skywatcher 8 inch newtonian on an EQ5 manual mount
or
- Skywatcher 10 inch collapsible dobsonian
Both a similarly priced.
Yes, the 10 inch aperature of the collapsible dob sounds inviting, however I'm worried that I'll very quickly get frustrated at having to continually nudge the scope to keep objects in the middle of the field of view. The 8 inch on the manual EQ5 mount should make this issue a lot easier to work through, though at the cost of aperature.
So, can I perhaps hear people's experiences of using a big phat dob to track objects and how annoying it can be to keep nudging the beast along?Perhaps it ain't that hard?
My idea of getting a manual EQ mount is that I can find my way around the sky, and, If I need to, pause to consult my star charts, then go back to the scope to continue the star hopping. An EQ tracking mount would allow me to quickly catch up where I left off. My concern is that with a dob it would be harder to take up where you left off, because there would be 2 axis' to correct and you'd get lost a lot easier.
My hair is falling out over this. Can anyone help me?
Cheers!
wavelandscott
27-09-2010, 10:33 PM
I'd encourage you to go to a viewing night and try "nudging" a Dobsonian mounted reflecting telescope on for size yourself.
I've never found pushing to be an issue when I was viewing myself.
One man's no problem is another's pain in the neck...try it out yourself and decide.
I'd think that there would be a number of undriven Dobs around the Blue Mountains...
You might guess from my post that I'd suggest the bigger scope...
mswhin63
28-09-2010, 11:46 AM
For visual, I would go for the 10" for future Astro Photography I would go for the EQ.
When I first joined I really didn't know what I wanted so I went for the DOB for budget and apeture. I am fortunate enough now that I can do photography after making an EQ platform which I am considering making for others when I have refined the process.
I must admit fisr time choices can be hard, if I joined an astro society in the first place then my selection would have matched what I initially mentioned.
Paddy
28-09-2010, 02:25 PM
Personally I have never found nudging a dob to be at all frustrating. It is quite a natural movement. To my mind, much quicker to get used to than setting up an EQ mount. Setting up an EQ does get easier with practice, but it seems to me that it would always take longer than setting up a dob.
You will get good at nudging the dob in no time Jowel. Good quality widefield eyepieces in your two most used focal lengths (10mm & 25mm) will help you no end, as the object will take longer to travel across the fov, so you won't need to nudge the dob as much. Just to note as well, the planets move across the fov a lot quicker than deep sky objects. I also use a Red Dot Finder, so if I lose things I can find them back much easier.
How about getting the 10" for now and adding an Argo Narvis down the track. Best of of both worlds :question:.
All this said and done Jowel, I think you pretty much answered your own question when you expressed that you may get frustrated nudging the dob. This hobby takes quite a bit of perseverance & patience. If we don't have it to begin with, we end up acquiring it. ;)
Have you looked into how much setting up an EQ mount involves? I just know that when I want to quickly get out there for a short session, my dob is ready to go at a whim. Drag it outside 30mins- 1hr before observing (to cool down) and that's it. When I'm finished, there's no packing up, I just drag it back in.
You've just got ask yourself what is going to be less of chore for you - setting up EQ mount or nudging a dob. The reason I went for a dob is because, I knew I lacked the patience to set up a mount and because of that, I was worried as to how often I would actually feel motivated to set it up everytime I wanted to use it. I now actually enjoy nudging the dob - I feel in control of my vehicle. Zoom zoom. :D
Nudging a dob will only be part of learning patience & tolerance... you then have targets to find as well... Though frustrating at times doing it manually, it is highly challenging and rewarding.
Kind regards,
Suzy.
asimov
28-09-2010, 10:23 PM
You've got the choice of nudging in 2 directions, or one. I know what I'd rather be doing. Add a motor when you decide to give the nudging away.
DavidU
28-09-2010, 10:34 PM
I will second that ! I also find you can get way smoother movement from a well tuned EQ mount (only needed to bump in one plane).
pgc hunter
28-09-2010, 10:55 PM
Depends on what you're after. If you're into visual and want the biggest scope you can afford/handle, go for the dob and learn to track manually. Eventually it'll be second nature, like driving a manual car ;) . You'll want smooth motions, as a jerky dob will create mass quantities of frustration. Not sure how the SW dobs fare in this department. You could get an EQ platform, but these are fairly pricey.
An EQ mount will provide easier tracking, but take more time and effort to set up properly (bigger learning curve aswell!). But take note, that a Newt on an EQ mount will result in awkward eyepiece positions which will require rotating the tube to get the EP in an ergonomically comfortable postition as you swing it across the sky. EQ mounted Newts are generally not recommended for visual for this reason, but you can get a set of rotating rings which will allow you to rotate the tube within its cradle.
I'd say try before you buy. You could try buying either the dob or EQ second hand and give it a good workout, that way you could re-sell it without monetary loss if it doesn't suit you.
asimov
28-09-2010, 10:55 PM
They'll all be calling us Lazy David - One direction bumpers only! HE-HEE!
michaellxv
28-09-2010, 11:51 PM
I hope you don't mean that literally :rofl:,you should be taking more care with your pride and joy.
Jowel, take a dob for a test drive. It's sooo much fun.
asimov
29-09-2010, 12:01 AM
Dobs are great at low magnification of course. It's only when viewing planets at reasonably high powers that it becomes frustrating. So all jokes aside - It really does depend on what you want to do most of.
mswhin63
29-09-2010, 12:09 AM
I will totally agree, without tracking DOB's are awful for closeup planetary, reasonable for wide moon. They are though great at high power when tracked.
asimov
29-09-2010, 12:40 AM
I started out with a so called 'DOB' back in the 70's. Back then they were called ALT AZ mounts. Imagine a dob on a 3 legged, big lump of pipe 3' high. I think I was at it for 2 weeks before asking my dad if we could make an EQ mount, which we did. 2 weeks after building the EQ, it was "dad, we need a motor!":lol:
:lol2: haha, I do actually drag it outside - she's on wheels, drag drag drag. :P:P:P
dannat
30-09-2010, 04:15 AM
Can I add unless it's a reasonable decent eq mount stick to the don - I would stay with an alt/az. If it was me
Mountain_Wanderer
06-10-2010, 06:51 PM
Decisions decisions...
Guys thanks so much for all this wonderful advice. It's a hard decision to make here. Either go for the 10" aperature over the 8". Or, go for a better tracking system (Eq) over the dob.
I'm trying to work out 2 key things here:
1. How much better is 10" over 8"? I hear that for planets, both are similar, but for deep sky objects the 10" is king. But then the 10 inch is bigger and harder to lug around and is only available in a dob mount. And I hear that the 8 inch can deliver a lot of good quality views and can do just about everything well.
2. Is a manual eq mount (non-motorised) much more better at tracking than a dob or is it only a marginal improvement and therefore not worth getting? I'd like to look at planets in high magnification. I'm worried that with a dob I'd be forced into using lower magnification and also the annoying problem of having to sharply shift the scope aong 2 axis to keep it in view. Would the eq mount allow me to magnify more and also provide a smooth movement of the scope to track planets? Though there's also the worry of how difficult it would be to align to the south pole every time I want to use it.
The temptation of larger aperature is there with the 10" but there seems to be a lot of concessions involved: larger, heavier, difficult tracking. Dunno whether I should fall for temptation or stick with the 8" which should do the job.
mswhin63
06-10-2010, 07:13 PM
I know you want to do both but ulimately what do will you end up doing.
Planetary mostly - 8" with tracking.
But if you intend to do DSO mostly which there is a lot more to see then 10" is the way to go. If you can wait a bit longer to save the pennies then track as well.
Even though I do planetary mostly, I know I made the right choice for 12" as I know I will further down the track will observe more DSO. I will also purchace a heavy duty mount for the DOB in the future or build one. DOB tracking was not available when I bought my scope.
Paddy
06-10-2010, 09:02 PM
the beauty of a dob alt-az mount is that while you are moving it in 2 axes, you do this simultaneously ie you just grab the top of the scope with your paw and move it. Simple. I view at high power and move the dob and sketch. It becomes second nature and is quite intuitive. I find observing with a dob very easy and while it would be a little easier for sketching to track, it's really not that hard. And a 10" is not that much more effort to move than an 8". But I would say that setting up with a 10" dob would be considerably quicker and simpler than setting up an 8" on an EQ. Especially if each time you will have to polar align the scope, even roughly. It's quicker to set up my 16" dob than my ED80 on CG-4 EQ even though I have the tripod position marked.
DavidU
06-10-2010, 09:16 PM
The Dec & RA motion control extensions are nice and easy to use and do not shake a high powered view. Old fashion ,simple and it works
Astroman
06-10-2010, 09:20 PM
I learnt on an Manual EQ mount and had an 8" newtonian on an Alt/Az base both have their good points and bad, if your after a reasonable GOTO but the simplicity of an Alt/az base for visual work, then the new computerised scopes from Skywatcher are ideal and a reasonably low cost. If you want to get into Astrophotography then a German Equatorial would be better. If you want to do live video then the Alt/az would be fine for that also. The choice is endless, I dont find the use of GOTO a problem infact most of the time you pick up where an object should be using GOTO, similar to star hopping, you eventually figure it out. One down side to an EQ mount for visual is the eyepiece tends to get in some weird and wonderful positions which can get quite awkward to get to. Hence the Alt/Az base as the eyepiece is usually at an place where you can get to it.
Good luck with your choices...
Mountain_Wanderer
09-10-2010, 12:52 PM
Just on the Skywatcher 10 inch collapsible dobsonian...
It is fair to say that if the up-down, left-right movements are silky smooth then tracking a planet at high magnification will be a lot more enjoyable?
If I want to track a planet at high mag, at what magnification do I need to see detail on mars, the bands and red spot on Jupiter, or the ring shadow of saturn? Can I have a low magnification for these or do I really need to take it up?
And just on deep sky objects, how good is a 10 inch aperature for detail on fainter objects, particularly galaxies? I know that 8 inches will show the object but not necessarily certain details. Would 10 inches deliver all the good stuff or is it still noticably limited? Take for example some of the more well known galaxies that are favourites for viewing (say the Sombrero galaxy). Will the 10 inch show all the basic features or do I need even more aperature???
I've also googled a bit about equatorial devices for dobsonians. They seem to exist? Maybe someone has some experience with attaching some sort of device to a dob that allows the scope to follow right ascention on a curved axis?
And just something about the base, this is shaping up as the more difficult thing to transport around. I wanted to fit everything in the boot of my small car. I feel the collapsed scope should fit in??? But then there's the bloody big base! That surely can't fit in the boot aswell? For long car trips to go on holidays where car seats are taken and room is at a premium, is it possible to disassemble the base and put it back together after the trip?
mswhin63
09-10-2010, 07:30 PM
For visual, a alt/az track is more than enough, your eyes are great compensators of field rotation. For Astrophotograhy EQ is a must although planetary is a bit more forgiving. Deep Sky Imaging EQ is the only way.
I agree about the bases, I have 2 cars, 1 is a small van Citreon Berlingo, no problems, but my Hyundai IC30CW (wagon) is not suitable for 12" at least, not sure abouth the 10" but feel will still be a bit limited.
sirius0
10-10-2010, 11:08 PM
Not that i'm qualified, I just use binoculars. But I would have thought that if an EQ was a nuisance for quick observation, then perhaps just set the equatorial as if it it is at the equator, latitude zero. Then just 'bump' the RA and DEC like an alt azimuth, for the visual results. Raise the pendants eyebrows who cares?
Mountain_Wanderer
14-10-2010, 09:27 PM
Hey dudes. Just a silly question I have...
When you look through an 8 inch scope on the EQ mount, can you sit down doing so, or do you need to stand up all the time? Or perhaps using a high stool to sit on is the answer? Sitting would be my preference.
Also, when you're looking through the telescope, are you able to easily move the scope along the axis without needing to take your eye away from the eyepiece? What I mean is, can your hands reach the telescope controls when you keep your eye glued to the eyepiece?
that_guy
14-10-2010, 09:48 PM
newts are a pain in the backside (literally) on EQ mounts... they get to some pretty weird places... and if you do this.. your gonna need an observing chair...
NorthernLight
14-10-2010, 11:28 PM
you not only need an observing chair but a ladder. In some (easily achievable) situations the focuser points vertical to the sky so you have to get something high enough to stay on and bend over the scope to be able to look in the EP. If you then want to move the scope you have to balance yourself whilst bending over the scope, move both your arms around it to reach the mount under it and twist the knobs. The other option is bury your mount halfway in the ground but then you have to lie infront of it to observe when the focuser points downwards. Of course you can also turn the tube in its rings but you will always loose your target thereby- and this becomes real fun when a barlow joins the game...
Get DOB! If ever want to do photography youŽll need buy a proper mount with ST-4 port anyways.
jamespierce
15-10-2010, 07:03 PM
8 inches is pretty big on a EQ ... to my mind the dob is a much simpler gentle telescope. When you're learning the sky unless the EQ5 has goto I'm not sure it's much of an advantage... the movements of the EQ are quite hard to get your head around when you're starting out. I'd recommend you go for the DOB (get a truss one if possible too) ... however, I think there is alot to be said for starting out with a 4" refractor, or a 5 or 6 inch SCT on a little goto mount.
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