Video astronomy set up

[JethroB76]

Hey guys, I'm looking for some starting suggestions to get me looking in the right direction for first time video astronomy.
I have a budget of say up to $3000 - I need a suitable mount, scope and camera.
I had thought maybe a wireless GStar camera with something like an ED80 mounted on an iOptron cube mount might be suitable. Or what about something like a goto 8" dob with the same camera?

What are people using and getting good results from? Does the budget need to go up? Perhaps the main requirement is that it is goto and relatively easy to set up and also reasonably portable (I want to stay clear of eq mounts)

I'm a bit out the loop at the moment so am in for some solid research before I pull the trigger - if anyone with some experience has suggestions on gear that would be suitable, or particular things that need to be considered please fire away :thumbsup:

[JethroB76]

Does anybody do any video astronomy?
Anyone own a gstar or mallincam or similar?

[Saturn%5]

Hi Jeff
I think ballaratdragons on these forums will be the man to talk to.

cheers

Graeme.

[DavidLJ]

Hi Jeff

I'm not sure which ED80 you are referring to but if it is the Skywatcher f/7.5 the following may be of some help.

Based on my own experience with using focal reducers and tele-extenders with the GStar camera and using SkyTools to marry that data with the specifications for the Skywatcher ED80, I believe that you will likely get the following FOVs :

With 2x barlow – 18':55” x 13':40”
At prime focus – 37':53” x 27':22”
With x0.5 focal reducer (it replaces the nosepiece) – 49':11” x 35':35”

That gives a fairly useful imaging range. For example you could almost, but not quite, capture the whole of the Sculptor Galaxy NGC253 when using the barlow. And at the other end of the scale you would need a 2 x 3 panel mosaic to mostly cover the Pleiades M45.

I can't opine on what, if any, vignetting you might get using the focal reducer.

David

[Derek Klepp]

http://www.astroholic.com/attachment.php?attachmentid=4608&d=1344428241
Jeff these are quick snapshots. I've been to busy looking at the Sun of Late.In all honesty the bigger the aperture the better the live view for galaxies and smaller objects.Although there has not been much activity on the Gstar group of late you may want to check it out.The newer Gstarex2 has less noise than the older version but not as many functions.Seeing you have a 12" Dob I think that plus the smaller aperture would be a great combo.For video Astronomy in Australia you may want to call myastroshop.
Derek

[Blue Skies]

Hi Jeff,

I don't use my Gstar video camera for general viewing or imaging at the moment, it's largely for trying to record occultations, which is a slightly different game to plain imaging, so I was waiting for someone else to say something!

The mount is important, more important that the scope, I think. But here is something important to think about...

The video camera will stick out a long way from the focuser. If you get a SCT on fork mounts and you want to look/image something near the zenith (if you've got it in alt-az alignment) or near the south celestial pole (if you're using a wedge and it in Equatorial mode) then look out! That big sticky-outy camera is going to go crunch on the forks. I've seen some clever people mod their video camera into entirely different configurations, but if you're like me and don't have the skills then this is something to keep in mind.

I accidentally got around this by buying an iOptron Minitower Pro, which suits my needs admirably. It's not heavy duty, but does point accurately, which is what I want. The upside is, and I didn't actually realise this until I had set it up a few times, is that the scope sits on the side of the mount and has the freedom to swing from 0 to 90 degrees in alt without hitting anything. I use an SCT, but I think other have said here that with a longer refractor they can hit the legs. There are ways around that, though. A german equatorial mount should also avoid a crunch happening.

The Gstars are a good cheap entry camera, but if you're wanting to do some serious imaging I would look at the other models around. I have a few too many hot pixels on the one I'm using at the moment for my liking, and that's even in x4 integrating mode, which is hardly tickling it. But for getting used to what video cameras can do it's fine.

Also keep in mind that depending on what you want to do, you might only want a small, widefield scope, rather than a big aperture or long focal length. The usual rules apply for scopes to video cameras as for any other kind of astrophotography and imaging gear. I'm currently looking at getting a short f/ratio refractor myself to add another option into my set up (as well as keep on trying to work out how to get a camera lens to attach to it, the T-C adpater doesn't completely solve the problem at the moment). So a suite of scopes might be the go rather than just one.

I would also recommend Myastroshop as a good place to start. I've always had good service and the owner is experienced with video camera use.

[DannyV]

Jeff,
I've got two Gstar-Ex Colour cameras from Astroshop. I have one hooked up to a WO 81 and the other with a 50mm cs lens as a spotter. At the moment I'm rebuilding my system, but up to now I've used these cameras as setup cameras to get my EOS dslr on to target. However I want to use the one on the WO81 as a live recording in addition to my dslr on my 800HD. They perform quite well, just visually - I haven't processed any images from them yet. I use them as I have to remote my system into my bedroom as due to health problems I can't stay out at my scope.
These are terrific little cameras they are about 2" (50mm) cubed, and I've wired all the menu buttons into my bedroom so I can change the integration etc on the fly (this would void the warranty I suspect).
Of course the whole thing is mounted on my Celesteron CPC mount and will now be on its Wedge for a polar alignment as well.
I've got the cameras hooked into my video security system, so I can see all channels at once, and record as well, or throw it across to my mac's usb recording.
I'd like to get a third camera when I can afford one - to use on my CPC800.

[tonybarry]

Hi Jeff,

I have used a GStar-EX quite a lot for video astronomy and occultation work.

It is a good cam, although it needs dark field subtraction to keep the hot pixels under control. Nebulosity does this well.

I used mine with an LX90-8" and a 0.65 focal reducer which required me to either keep the max altitude below 65 degrees, or use a 2" diagonal to point the cam so it did not hit the fork base. With this I had a FoV of about 20 arc min.

With Nebulosity to stack, I obtained many excellent images (mainly of galaxies which at the time was my interest).

The LX90 had relatively poor worms in it and it was mounted alt-az, which to the purist is anathema for astro photo work. But this all proved to be an excellent setup; the integration of 2.5 sec was just right for getting maybe 70 % of the images without smear, and the large Periodic Error pushed the camera field of view around enough to wipe out the hot pixels with dark subtraction. If the PE had been much less, the dark subtraction would have left ugly "holes" in the subtracted image ... as it was, the results were very pleasing.

Regards,
Tony Barry
WSAAG

[JethroB76]

Tthanks for the replies so far guys (and PMs).

Some interesting comments - Jacquie, at this stage I am leaning towards an ioptron altaz mount (minitower or similar) unless somebody comes up with a good reason not to. The clearance issues mentioned are why I am not considering a fork mounted scope.
The gstar ex2 maybe the camera I go with.
To be honest I think its the scope that is my main problem - I have read that a faster scope is better? Also while bigger aperture would be good, I do want to maintain reasonable portability and obviously will need to work with in the carrying capacity of the mount.

Should also clarify that at this stage mainly interested in live observation rather that astrophotography as such..

[JethroB76]

Has anyone tried observing using a camera such as the gstar on a goto dob? How about with one of the gso rc scopes?

[rogerco]

Whenever you think of using a camera on a dob you have to check the focuser which is generally designed for an eyepiece, the sensor in a Gstar isn't too far back so it will probably be ok but I would check.

[Graeme Bluestar]

Definitely check your focus if using a Gstar. I have just finished installing a 16" Lightbridge on a GEM mount to use for video timing of lunar occultations. With a Gstar fitted there is not quite enough inward travel with the Meade focuser. By discarding the Meade 2" to 1.25" adaptor I should overcome this problem. A friend is machining an adaptor without the shoulder/compression ring/ thumbscrew design of the Meade adaptor. I have found the 1.25" dimension of the Gstar nosepiece to be only approximate at best, so we can fix that aspect at the same time. Fitting a couple of recessed grub screws into this new adaptor will allow me to tighten it onto the Gstar nosepiece before installing in the Meade focuser.

[Poita]

I was never happy with an Alt/Az setup with my Mallincam Extreme, It worked far better on an EQ mount.
I was using it with a fast ED80 and a faster Hyperstar setup.

The ideal setup to me is a C8 with hyperstar and a Gstar EX or Mallincam.

Aperture isn't all that important, but a fast f ratio is.

[JethroB76]

Hmm, interesting stuff guys. I understand focuser travel being a potential issue with a dob, but one I can get around..
Trying to avoid a gem for portability and the fact I aim to loan it to my father for periods of time hence a simpler set up would be best - is rotation an issue with altaz mounts for this purpose?