Dumb questions - yet again

[earth titan]

I know (looks slightly embarrased). Here he is again with daft questions but please indulge me...

1. I have an EQ3 mount on my 150 newtonian. I'm guessing a bigger scope (say 250) would need a more robust mount?

2. Would a skywatcher 250px dobsonian, with auto tracking, be suitable for imaging in the future?

3. Am I annoying everyone with my continual questions?

[Moonshane]

I know (looks slightly embarrased). Here he is again with daft questions but please indulge me... there are no daft questions. And rest assured there will be others before and after you wondering the same things you will be! I'm still a relative newb compared with most on here but here's my thoughts.

1. I have an EQ3 mount on my 150 newtonian. I'm guessing a bigger scope (say 250) would need a more robust mount? Definitely. Most manufacturers seem to put scopes with mounts that can only just hold the scope they are selling them with. You'd need a substantial mount (probably about £300-500 used plus tripod) to cope with a 250 and if you went to a 300 you'd need to spend even more.

2. Would a skywatcher 250px dobsonian, with auto tracking, be suitable for imaging in the future? I'd suggest it would be fine for webcam imaging of planets/moon and for prime focus DSLR of the moon but not for DSOs. You'd again need to spend maybe £600 at least on just a mount for DSOs. I'm not an imager, this is just what I have read on other posts.

3. Am I annoying everyone with my continual questions?definitely not!

Hope the above helps. Personally, I would only say that you should image if you have one scope for imaging and one scope for observing. I tried a few moon shots but found that I missed seeing what was going on through the eyepiece so have not followed the photography path (despite being well into other forms of photography).

Cheers

Shane

[Ben Ritchie]

2. Would a skywatcher 250px dobsonian, with auto tracking, be suitable for imaging in the future?

In addition to what Shane says, it's an Alt-Az system so even if the tracking is good enough for long-exposure imaging you'll get field rotation (stars appearing to trail around the centre of the field of view). But for webcam imaging of the moon and planets it'll be fine.

[Demonperformer]

If you are good at DIY, I suppose it might be possible to set up some sort of motor at the eyepiece/camera connection to rotate the camera the other way to compensate for this field rotation? Would need to be a pretty accurate. No idea if this would be workable, but seems as if it should be possible (in theory).

[Digz]

In response to question 2 and Shane's comments, partially - you could get some images of DSO's with this scope, most certainly - I have done it with a similar scope.

Don't get me wrong, Im no expert and certain DSO's wont be possible, for example M31 as its a large object and with that focal length of a 250px you wont get it all inframe.

Here are some (very poor) shots with a 250p ds:

http://stargazerslounge.com/imaging-deep-sky/112458-various-dsos-first-attempt.html-

http://stargazerslounge.com/imaging-deep-sky/112545-first-m57.html

Now these are not technically perfect, far from it. But they were taking with a D200 @ prime focus. The difference here is that I am using a German Equatorial mount (GEM) not a dob which is really the best way forward to astro-imaging if your serious about it.

I suppose it all comes down to what kind of astro-imaging you want to do?

[Ben Ritchie]

If you are good at DIY, I suppose it might be possible to set up some sort of motor at the eyepiece/camera connection to rotate the camera the other way to compensate for this field rotation? Would need to be a pretty accurate. No idea if this would be workable, but seems as if it should be possible (in theory).

It's possible - large telescopes use derotators, and Meade sold one for the LX200 line (which, as an aside, is quite possibly the worst bit of astro-kit i've ever used!). Main problem is that the derotation rate varies with position on the sky, so your solution needs to know where you're pointing.

[Earl]

You could make a large equatorial wedge for the dob

[Rossco72]

There are no daft questions - only daft answers!

Astrophotography is expensive, period. If you are looking to go down that road, give serious consideration to your budget. Many thousands of pounds can be spent on equipment in an effort to get decent DSO images.

However, as has been pointed out, webcam imaging is an option, lots of quick frames stacked and sorted. Using a Dobsonian this is your only real option. You can get good planetary and Lunar shots with relatively cheap equipment. Plus the Dobsonian will give you pleanty of mirror for your buck, opening up a lot of visual possibilities which wouldn't be there with say a dedicated APO for imaging (unless you are talking about 180mm AP monsters!!)

So, If you want to get into DSO imaging, look at an EQ6 or better mount, you will need a guidescope, Main scope, Guidecam and imaging cam. Possibly a laptop, software and loads of powertanks or extension leads.

If you want very good visuals and the odd webcam of a planet or the moon then you will be LOADS cheaper with a dob...

Cheers

[Moonshane]

In response to question 2 and Shane's comments, partially - you could get some images of DSO's with this scope, most certainly - I have done it with a similar scope.

Don't get me wrong, Im no expert and certain DSO's wont be possible, for example M31 as its a large object and with that focal length of a 250px you wont get it all inframe.

Here are some (very poor) shots with a 250p ds:

http://stargazerslounge.com/imaging-deep-sky/112458-various-dsos-first-attempt.html-

http://stargazerslounge.com/imaging-deep-sky/112545-first-m57.html

Now these are not technically perfect, far from it. But they were taking with a D200 @ prime focus. The difference here is that I am using a German Equatorial mount (GEM) not a dob which is really the best way forward to astro-imaging if your serious about it.

I suppose it all comes down to what kind of astro-imaging you want to do?

Digz, I am not sure what you are saying? Did you take these images with the EQ or with the dob tracking base?

Clearly with a good quality motorised/tracking/goto EQ you can get good results with most OTAs but not with the tracking dob base??

[Digz]

Hey shane, sorry 'bout that, its not the clearist of prose I have ever written. Plus, rereading what you said I understand it a little more and realise where the confusion came from.

I was trying to point out that the size (aperture / focal length) of the scope will do DSO's wheras you were talking about the scope being a dob and therefore not best suited to DSO's. The images above were taking with an EQ mount, an NEQ6 Pro.

Your last sentence is spot on and what I was trying to get at, I apologise for muddying the waters :)

[Moonshane]

ha ha no worries mate, I just wanted to make sure that the advice was clear - as it happens we were 'singing from the same hymn sheet'

[Digz]

Indeed we were

[Vega]

Visit my website and go to the DSO Gallery... lots of my DSO photo's were taken through my 250px with Canon DSLR (on an EQ6 Synscan pro mount). Namely M1, M13, M27, M51, M57, M81, M97, M99, M101, Bubble Nebula, Leo Triplet.

I'll 2nd what digz said. You wont get M31 in the field of view (however you can get wonderful close up shots of the dust lanes ;-). The 250px has been ideal for taking shots of planetary nebulea, excels at globular clusters and very good for galaxies (with the 1 exception of Andromeda). You can perfectly fit the Orion Nebula in it with a Canon DSLR. I too have been very sucessful with webcam shots of planets through it.

On the mount side of things... look at nothing less than an EQ6 for imaging with this scope. Its a beast. The EQ6 Synscan throws it round like a toy mind you, awesome mount :-)

Matt